Edge application server discovery method and device and network equipment

Abstract

The invention provides a discovery method and device of an edge application server and network equipment. The method comprises: determining whether the traffic of an application supports routing to a local DN of a VPLMN; if the traffic of the application supports routing to the local DN of the VPLMN, determining to select a public EAS deployed in the VPLMN or a public DNAI for accessing the VPLMN for the terminal; and if the traffic of the application does not support the routing to the local DN of the VPLMN, determining to select a public EAS deployed in the HPLMN or a public DNAI for accessing the HPLMN for the terminal. In the application, the SMF determines whether the flow of the application to be used by the terminal supports the routing to the local DN of the VPLMN or not, thereby selecting the public EAS or the public DNAI deployed in the VPLMN for the terminal, or selecting the public EAS or the public DNAI deployed in the HPLMN.

Description

Technical Field

[0001] The present application relates to the field of communication technology, and in particular to a method, device and network equipment for discovering an edge application server. Background Art

[0002] Mobile Edge Computing (MEC) technology migrates computing storage and business service capabilities to the edge of the network, avoiding the need to transmit data back to the cloud as much as possible, reducing the waiting time and network costs of data going back and forth between the cloud and the cloud. Based on the 5G distributed cloud infrastructure, 5G user planes and 5G MEC nodes are built on the edge cloud. 5G MEC nodes provide the MEC application platform to realize the deployment and management capabilities of third-party applications. Users can obtain services through MEC applications.

[0003] In the prior art, only a common edge application server (EAS) or a common data network access identifier (DNAI) can be selected for a group of non-roaming user equipment (UE). In the scenario where a group of UEs need to access the same edge application server, it is impossible to select a suitable edge application server for the roaming UE. Summary of the invention

[0004] The purpose of the present application is to provide a method, device and network equipment for discovering an edge application server, which solves the problem of being unable to select a suitable edge application server for a roaming UE.

[0005] An embodiment of the present application provides a method for discovering an edge application server, which is executed by a session management function (SMF). The method includes:

[0006] Determine whether the application's traffic supports routing to the local data network (Data Network, DN) of the visited public land mobile network (VPLMN);

[0007] If the traffic of the application supports routing to the local DN of the VPLMN, it is determined that a public edge application server EAS deployed in the VPLMN or a public data network access identifier DNAI for accessing the VPLMN is selected for the terminal;

[0008] If the traffic of the application does not support routing to the local DN of the VPLMN, it is determined that a public EAS deployed in a Home Public Land Mobile Network (HPLMN) or a public DNAI for accessing the HPLMN is selected for the terminal.

[0009] Optionally, the determining whether the traffic of the application supports routing to a local DN of a visited public land mobile network VPLMN includes:

[0010] Determining, based on the received first information, whether the traffic branch of the application supports routing to the local DN of the VPLMN;

[0011] The first information is: a policy and charging control (PCC) rule sent by a policy control function (PCF) or a first request message sent by an application function (AF); or, the first information is: a DNS query request sent by a terminal.

[0012] Optionally, the PCC rule includes at least one of the following information:

[0013] Traffic correlation identification;

[0014] EAS relevance indication;

[0015] Application information;

[0016] The Internet Protocol (IP) address or the candidate public DNAI of the candidate public EAS selected by the AF for the terminal.

[0017] Optionally, the first request message includes at least one of the following information:

[0018] Terminal identification;

[0019] EAS relevance indication;

[0020] Traffic correlation identification;

[0021] Traffic correlation indication;

[0022] Application information;

[0023] The IP address or the candidate public DNAI of the candidate public EAS selected by the AF for the terminal.

[0024] Optionally, determining, according to the received first information, whether the traffic of the application supports routing to the local DN of the VPLMN includes at least one of the following:

[0025] In the case where the first information includes application information, if the application information included in the first information allows being routed to the local DN of the VPLMN, it is determined that traffic of the application supports being routed to the local DN of the VPLMN; if the application information included in the first information does not allow being routed to the local DN of the VPLMN, it is determined that traffic of the application does not support being routed to the local DN of the VPLMN;

[0026] or,

[0027] In the case that the first information includes application information and the IP address of the candidate public EAS or the candidate public DNAI selected by the AF for the terminal, if the candidate public EAS is deployed in the VPLMN or the candidate public DNAI is used to access the VPLMN, and the application information and the candidate public EAS or the candidate public DNAI contained in the first information are allowed to be routed to the local DN of the VPLMN, it is determined that the traffic of the application supports routing to the local DN of the VPLMN; if the candidate public EAS is deployed in the VPLMN or the candidate public DNAI is used to access the VPLMN, and the application information and the candidate public EAS or the candidate public DNAI contained in the first information are not allowed to be routed to the local DN of the VPLMN, it is determined that the traffic of the application does not support routing to the local DN of the VPLMN.

[0028] Optionally, the application information included in the first information is allowed to be routed to the local DN of the VPLMN, including:

[0029] The application information in the VPLMN uninstall information includes the application information in the first information;

[0030] The candidate public EAS or candidate public DNAI allows being routed to the local DN of the VPLMN, including:

[0031] The IP range in the VPLMN offload information includes the IP address of the candidate public EAS.

[0032] Optionally, the method further includes:

[0033] In the case where the first information includes the IP address of the candidate public EAS or the candidate public DNAI selected by the AF for the terminal, if it is determined that the traffic of the application supports routing to the local DN of the VPLMN, then determining the candidate public EAS or the candidate public DNAI as the public EAS or public DNAI of the terminal;

[0034] When the first information includes the IP address of the candidate public EAS or the candidate public DNAI selected by the AF for the terminal, if it is determined that the traffic of the application does not support routing to the local DN of the VPLMN, a public EAS deployed in the HPLMN or a public DNAI for accessing the HPLMN is reselected for the terminal.

[0035] Optionally, the determining, according to the received first information, whether the traffic of the application supports routing to the local DN of the VPLMN further includes:

[0036] In the case where the first information includes the IP address or candidate public DNAI of the candidate public EAS selected by the AF for the terminal, if the candidate public EAS is deployed in the HPLMN or the candidate public DNAI is used to access the HPLMN, it is determined that the traffic of the application does not support routing to the local DN of the VPLMN.

[0037] Optionally, the method further includes:

[0038] If the SMF is the SMF of the HPLMN, and the traffic of the application supports routing to the local DN of the VPLMN, sending the second information to the SMF of the VPLMN;

[0039] The second information includes at least one of the following:

[0040] EAS relevance indication;

[0041] Traffic correlation identification;

[0042] Application information;

[0043] The IP address or the candidate public DNAI of the candidate public EAS selected by the AF for the terminal.

[0044] Optionally, the method further includes:

[0045] If the SMF is the SMF of the VPLMN, and the traffic of the application does not support routing to the local DN of the VPLMN, sending third information to the SMF of the HPLMN;

[0046] The third information includes at least one of the following:

[0047] EAS relevance indication;

[0048] Traffic correlation identification;

[0049] Application information.

[0050] Optionally, the method further includes:

[0051] If the SMF is the SMF of the VPLMN, and it is determined that a public EAS deployed in the VPLMN or a public DNAI for accessing the VPLMN is selected for the terminal, a Domain Name System (DNS) message processing rule is sent to an Edge Application Server Discovery Function (EASDF) of the VPLMN;

[0052] The DNS message processing rule is used to indicate: when the application information contained in the DNS query meets the application information range configured by the SMF of the VPLMN, select a public EAS deployed in the VPLMN or a public DNAI for accessing the VPLMN for the terminal.

[0053] Optionally, the method further includes:

[0054] determining a candidate DNAI based on the fourth information;

[0055] Sending the candidate DNAI to the AF;

[0056] The fourth information includes at least one of the following:

[0057] Terminal location information;

[0058] Available DNAI information;

[0059] VPLMN uninstall information

[0060] EAS deployment information.

[0061] Optionally, the application information includes at least one of the following:

[0062] At least one fully qualified domain name (FQDN);

[0063] At least one EAS IP address.

[0064] An embodiment of the present application provides a method for discovering an edge application server, which is executed by an AF and includes:

[0065] Sending a first request message to a target network element of the VPLMN;

[0066] The first request message includes at least one of the following information:

[0067] Terminal identification;

[0068] EAS relevance indication;

[0069] Traffic correlation identification;

[0070] Traffic correlation indication;

[0071] Application information;

[0072] The IP address or the candidate public DNAI of the candidate public EAS selected by the AF for the terminal.

[0073] Optionally, before sending the first request message to the target network element of the VPLMN, the method further includes:

[0074] Receive candidate DNAI sent by SMF;

[0075] According to the candidate DNAI, a candidate public EAS or a candidate public DNAI is selected for the terminal.

[0076] Optionally, the sending the first request message to the target network element of the VPLMN includes at least one of the following:

[0077] Sending the first request message to the SMF of the VPLMN through a Network Exposure Function (NEF) and / or a Unified Data Repository (UDR) of the VPLMN;

[0078] The first request message is sent to the PCF of the VPLMN through the NEF and / or UDR of the VPLMN, so that the PCF of the VPLMN generates a PCC rule according to the first request message and sends the PCC rule to the SMF of the VPLMN.

[0079] Optionally, the application information includes at least one of the following:

[0080] At least one FQDN;

[0081] At least one EAS IP address.

[0082] Optionally, the determining whether the traffic of the application supports routing to a local DN of a visited public land mobile network VPLMN includes:

[0083] If it is determined that the FQDN carried in the DNS query request sent by the terminal is authorized by the SMF of the HPLMN, it is determined that the traffic of the application supports routing to the local DN of the VPLMN;

[0084] or,

[0085] If it is determined that the FQDN carried in the DNS query request sent by the terminal has not been authorized by the SMF of the HPLMN, it is determined that the traffic of the application does not support routing to the local DN of the VPLMN.

[0086] Optionally, the determining that the terminal selects a public EAS deployed in a VPLMN or a public DNAI for accessing the VPLMN includes:

[0087] If the FQDN carried in the DNS query request sent by the terminal matches the FQDN sent by the NEF of the VPLMN and is configured with an EAS correlation indication or a traffic correlation indication, it is determined that the terminal selects a public EAS deployed in the VPLMN or a public DNAI for accessing the VPLMN.

[0088] Optionally, when it is determined that the traffic of the application supports routing to the local DN of the VPLMN, the method further includes:

[0089] If the notification message sent by the NEF of the VPLMN does not include the IP address of the public EAS, or the SMF of the VPLMN determines to select a new EAS for the terminal, the public EAS deployed in the VPLMN is discovered;

[0090] If the SMF of the VPLMN has an IP address of a public EAS, the IP address of the public EAS is determined as the public EAS deployed in the VPLMN selected for the terminal.

[0091] Optionally, when it is determined that the traffic of the application does not support routing to the local DN of the VPLMN, the method further includes:

[0092] If the notification message sent by the NEF of the VPLMN does not include the IP address of the public EAS, or the SMF of the VPLMN determines to select a new EAS for the terminal, at least one of the following is performed:

[0093] Discover the public EAS deployed in the HPLMN;

[0094] Sending fifth information to the SMF of the HPLMN, the fifth information being used to request the SMF of the HPLMN to discover a public EAS; the fifth information comprising at least one of an EAS correlation indication, a traffic correlation identifier, and an FQDN;

[0095] Sending a second request message to the NEF of the VPLMN and / or the NEF of the HPLMN, where the second request message is used to request the NEF to determine a common EAS;

[0096] If the SMF of the VPLMN has an IP address of a public EAS, the IP address of the public EAS is determined as the public EAS deployed in the HPLMN selected for the terminal.

[0097] Optionally, the method further includes:

[0098] The IP address of the public EAS is sent to the NEF of the VPLMN and / or the NEF of the HPLMN.

[0099] Optionally, in the case where traffic of the application supports routing to a local DN of a VPLMN, the method further includes:

[0100] If the notification message sent by the NEF of the VPLMN does not include the public DNAI, a third request message is sent to the NEF of the VPLMN, where the third request message is used to request the NEF of the VPLMN to determine the public DNAI.

[0101] Optionally, the method further includes:

[0102] The DNAI is determined based on the public EAS.

[0103] Optionally, the method further includes:

[0104] Sending a DNS message processing rule to the EASDF of the VPLMN, wherein the DNS message processing rule is used to instruct the EASDF of the VPLMN to send the IP address of the public EAS to the terminal;

[0105] The DNS message processing rules include: a public EAS IP address and forwarding operation instruction information set to directly respond to the DNS request.

[0106] Optionally, the method further includes:

[0107] Sending sixth information to the EASDF of the VPLMN; the sixth information includes information for constructing an EDNS client subnet option; or, the sixth information includes information of a local DNS server associated with a public DNAI.

[0108] Optionally, the method further includes:

[0109] Sending a first subscription message to the NEF of the VPLMN and / or the NEF of the HPLMN, where the first subscription message is used to subscribe to a notification message of the AF traffic impact request information;

[0110] Receiving a first notification message sent by the NEF of the VPLMN and / or the NEF of the HPLMN;

[0111] The first notification message includes at least one of the following information:

[0112] Traffic correlation identification;

[0113] EAS relevance indication;

[0114] Traffic correlation indication;

[0115] The IP address of the public EAS;

[0116] Public DNAI;

[0117] FQDN;

[0118] Information about NEF.

[0119] The embodiment of the present application also provides a method for discovering an edge application server, which is executed by the NEF and includes:

[0120] Receiving a first subscription message sent by the SMF of the VPLMN, where the first subscription message is used to subscribe to a notification message of AF traffic impact request information;

[0121] Sending a first notification message to the SMF of the VPLMN;

[0122] The first notification message includes at least one of the following information:

[0123] Traffic correlation identification;

[0124] EAS relevance indication;

[0125] Traffic correlation indication;

[0126] The IP address of the public EAS;

[0127] Public DNAI;

[0128] FQDN;

[0129] Information about NEF.

[0130] Optionally, the method further includes:

[0131] Sending a second subscription message to the UDR of the VPLMN, where the second subscription message is used to subscribe to a notification message of the AF traffic impact request information;

[0132] receiving a second notification message sent by the UDR of the VPLMN;

[0133] The sending a first notification message to the SMF of the VPLMN includes:

[0134] When it is determined according to the second notification message that the terminal affected by the AF request is a roaming terminal, sending the first notification message to the SMF of the VPLMN;

[0135] The second notification message includes at least one of the following:

[0136] Traffic correlation identification;

[0137] EAS relevance indication;

[0138] Traffic correlation indication;

[0139] The IP address of the public EAS;

[0140] Public DNAI;

[0141] FQDN;

[0142] Space validity conditions.

[0143] Optionally, the method further includes:

[0144] If the NEF of the VPLMN does not have the IP address or public DNAI of the public EAS associated with the traffic correlation identifier, a fourth request message is sent to the NEF of the HPLMN, where the fourth request message is used to request the IP address or public DNAI of the public EAS.

[0145] Optionally, the method further includes:

[0146] Receiving a second request message sent by the SMF of the VPLMN;

[0147] A public EAS is determined according to the second request message.

[0148] Optionally, the method further includes:

[0149] receiving a third request message sent by the SMF of the VPLMN;

[0150] A public DNAI is determined according to the third request message.

[0151] Optionally, the method further includes:

[0152] Receive the IP address of the public EAS sent by the SMF of the VPLMN, where the public EAS is discovered by the SMF of the VPLMN.

[0153] An embodiment of the present application provides a method for discovering an edge application server, which is executed by a PCF of a VPLMN. The method includes:

[0154] receiving a first request message;

[0155] generating a PCC rule according to the first request message;

[0156] Sending the PCC rules to the SMF of the VPLMN;

[0157] The first request message includes at least one of the following information:

[0158] Terminal identification;

[0159] EAS relevance indication;

[0160] Traffic correlation identification;

[0161] Traffic correlation indication;

[0162] Application information;

[0163] The IP address or candidate public DNAI of the candidate public EAS selected by the AF for the terminal;

[0164] The PCC rule includes at least one of the following information:

[0165] Traffic correlation identification;

[0166] EAS relevance indication;

[0167] Application information;

[0168] The IP address or the candidate public DNAI of the candidate public EAS selected by the AF for the terminal.

[0169] Optionally, the receiving a first request message includes:

[0170] Receive a first request message sent by the NEF and / or UDR of the VPLMN.

[0171] Optionally, the application information includes at least one of the following:

[0172] At least one FQDN;

[0173] At least one EAS IP address.

[0174] An embodiment of the present application provides a network device, including: a memory, a transceiver, and a processor:

[0175] A memory for storing a computer program; a transceiver for receiving and sending data under the control of the processor; and a processor for reading the computer program in the memory and performing the following operations:

[0176] Determine whether the traffic of the application supports routing to the local data network DN of the visited public land mobile network VPLMN;

[0177] If the traffic of the application supports routing to the local DN of the VPLMN, it is determined that a public edge application server EAS deployed in the VPLMN or a public data network access identifier DNAI for accessing the VPLMN is selected for the terminal;

[0178] If the traffic of the application does not support routing to the local DN of the VPLMN, it is determined that a public EAS deployed in the home public land mobile network HPLMN or a public DNAI for accessing the HPLMN is selected for the terminal.

[0179] Optionally, the processor is configured to read the computer program in the memory and perform the following operations:

[0180] Determining, according to the received first information, whether the traffic of the application supports routing to the local DN of the VPLMN;

[0181] The first information is: a policy and charging control PCC rule sent by a policy control function PCF or a first request message sent by an application function AF; or, the first information is: a DNS query request sent by a terminal.

[0182] Optionally, the PCC rule includes at least one of the following information:

[0183] Traffic correlation identification;

[0184] EAS relevance indication;

[0185] Application information;

[0186] The Internet Protocol IP address or the candidate public DNAI of the candidate public EAS selected by the AF for the terminal.

[0187] Optionally, the first request message includes at least one of the following information:

[0188] Terminal identification;

[0189] EAS relevance indication;

[0190] Traffic correlation identification;

[0191] Traffic correlation indication;

[0192] Application information;

[0193] The IP address or the candidate public DNAI of the candidate public EAS selected by the AF for the terminal.

[0194] Optionally, the processor is configured to read the computer program in the memory and perform at least one of the following operations:

[0195] In the case where the first information includes application information, if the application information included in the first information allows being routed to the local DN of the VPLMN, it is determined that traffic of the application supports being routed to the local DN of the VPLMN; if the application information included in the first information does not allow being routed to the local DN of the VPLMN, it is determined that traffic of the application does not support being routed to the local DN of the VPLMN;

[0196] or,

[0197] In the case that the first information includes application information and the IP address of the candidate public EAS or the candidate public DNAI selected by the AF for the terminal, if the candidate public EAS is deployed in the VPLMN or the candidate public DNAI is used to access the VPLMN, and the application information and the candidate public EAS or the candidate public DNAI contained in the first information are allowed to be routed to the local DN of the VPLMN, it is determined that the traffic of the application supports routing to the local DN of the VPLMN; if the candidate public EAS is deployed in the VPLMN or the candidate public DNAI is used to access the VPLMN, and the application information and the candidate public EAS or the candidate public DNAI contained in the first information are not allowed to be routed to the local DN of the VPLMN, it is determined that the traffic of the application does not support routing to the local DN of the VPLMN.

[0198] Optionally, the application information included in the first information is allowed to be routed to the local DN of the VPLMN, including:

[0199] The application information in the VPLMN uninstall information includes the application information in the first information;

[0200] The candidate public EAS or candidate public DNAI allows being routed to the local DN of the VPLMN, including:

[0201] The IP range in the VPLMN offload information includes the IP address of the candidate public EAS.

[0202] Optionally, the processor is configured to read the computer program in the memory and perform the following operations:

[0203] In the case where the first information includes the IP address of the candidate public EAS or the candidate public DNAI selected by the AF for the terminal, if it is determined that the traffic of the application supports routing to the local DN of the VPLMN, then determining the candidate public EAS or the candidate public DNAI as the public EAS or public DNAI of the terminal;

[0204] When the first information includes the IP address of the candidate public EAS or the candidate public DNAI selected by the AF for the terminal, if it is determined that the traffic of the application does not support routing to the local DN of the VPLMN, a public EAS deployed in the HPLMN or a public DNAI for accessing the HPLMN is reselected for the terminal.

[0205] Optionally, the processor is configured to read the computer program in the memory and perform the following operations:

[0206] In the case where the first information includes the IP address or candidate public DNAI of the candidate public EAS selected by the AF for the terminal, if the candidate public EAS is deployed in the HPLMN or the candidate public DNAI is used to access the HPLMN, it is determined that the traffic of the application does not support routing to the local DN of the VPLMN.

[0207] Optionally, the processor is configured to read the computer program in the memory and perform the following operations:

[0208] If the SMF is the SMF of the HPLMN, and the traffic of the application supports routing to the local DN of the VPLMN, sending the second information to the SMF of the VPLMN;

[0209] The second information includes at least one of the following:

[0210] EAS relevance indication;

[0211] Traffic correlation identification;

[0212] Application information;

[0213] The IP address or the candidate public DNAI of the candidate public EAS selected by the AF for the terminal.

[0214] Optionally, the processor is configured to read the computer program in the memory and perform the following operations:

[0215] If the SMF is the SMF of the VPLMN, and the traffic of the application does not support routing to the local DN of the VPLMN, sending third information to the SMF of the HPLMN;

[0216] The third information includes at least one of the following:

[0217] EAS relevance indication;

[0218] Traffic correlation identification;

[0219] Application information.

[0220] Optionally, the processor is configured to read the computer program in the memory and perform the following operations:

[0221] If the SMF is the SMF of the VPLMN, and it is determined that a public EAS deployed in the VPLMN or a public DNAI for accessing the VPLMN is selected for the terminal, a DNS message processing rule is sent to the EASDF of the VPLMN;

[0222] The DNS message processing rule is used to indicate: when the application information contained in the DNS query meets the application information range configured by the SMF of the VPLMN, select a public EAS deployed in the VPLMN or a public DNAI for accessing the VPLMN for the terminal.

[0223] Optionally, the processor is configured to read the computer program in the memory and perform the following operations:

[0224] determining a candidate DNAI based on the fourth information;

[0225] Sending the candidate DNAI to the AF;

[0226] The fourth information includes at least one of the following:

[0227] Terminal location information;

[0228] Available DNAI information;

[0229] VPLMN uninstall information

[0230] EAS deployment information.

[0231] Optionally, the application information includes at least one of the following:

[0232] At least one fully qualified domain name (FQDN);

[0233] At least one EAS IP address.

[0234] Optionally, the processor is configured to read the computer program in the memory and perform the following operations:

[0235] If it is determined that the FQDN carried in the DNS query request sent by the terminal is authorized by the SMF of the HPLMN, it is determined that the traffic of the application supports routing to the local DN of the VPLMN;

[0236] or,

[0237] If it is determined that the FQDN carried in the DNS query request sent by the terminal has not been authorized by the SMF of the HPLMN, it is determined that the traffic of the application does not support routing to the local DN of the VPLMN.

[0238] Optionally, the processor is configured to read the computer program in the memory and perform the following operations:

[0239] If the FQDN carried in the DNS query request sent by the terminal matches the FQDN sent by the NEF of the VPLMN and is configured with an EAS correlation indication or a traffic correlation indication, it is determined that the terminal selects a public EAS deployed in the VPLMN or a public DNAI for accessing the VPLMN.

[0240] Optionally, the processor is configured to read the computer program in the memory and perform the following operations:

[0241] If the notification message sent by the NEF of the VPLMN does not include the IP address of the public EAS, or the SMF of the VPLMN determines to select a new EAS for the terminal, the public EAS deployed in the VPLMN is discovered;

[0242] If the SMF of the VPLMN has an IP address of a public EAS, the IP address of the public EAS is determined as the public EAS deployed in the VPLMN selected for the terminal.

[0243] Optionally, the processor is configured to read the computer program in the memory and perform the following operations:

[0244] If the notification message sent by the NEF of the VPLMN does not include the IP address of the public EAS, or the SMF of the VPLMN determines to select a new EAS for the terminal, at least one of the following is performed:

[0245] Discover the public EAS deployed in the HPLMN;

[0246] Sending fifth information to the SMF of the HPLMN, the fifth information being used to request the SMF of the HPLMN to discover a public EAS; the fifth information comprising at least one of an EAS correlation indication, a traffic correlation identifier, and an FQDN;

[0247] Sending a second request message to the NEF of the VPLMN and / or the NEF of the HPLMN, where the second request message is used to request the NEF to determine a common EAS;

[0248] If the SMF of the VPLMN has an IP address of a public EAS, the IP address of the public EAS is determined as the public EAS deployed in the HPLMN selected for the terminal.

[0249] Optionally, the processor is configured to read the computer program in the memory and perform the following operations:

[0250] The IP address of the public EAS is sent to the NEF of the VPLMN and / or the NEF of the HPLMN.

[0251] Optionally, the processor is configured to read the computer program in the memory and perform the following operations:

[0252] If the notification message sent by the NEF of the VPLMN does not include the public DNAI, a third request message is sent to the NEF of the VPLMN, where the third request message is used to request the NEF of the VPLMN to determine the public DNAI.

[0253] Optionally, the processor is configured to read the computer program in the memory and perform the following operations:

[0254] The DNAI is determined based on the public EAS.

[0255] Optionally, the processor is configured to read the computer program in the memory and perform the following operations:

[0256] Sending a DNS message processing rule to the EASDF of the VPLMN, wherein the DNS message processing rule is used to instruct the EASDF of the VPLMN to send the IP address of the public EAS to the terminal;

[0257] The DNS message processing rules include: a public EAS IP address and forwarding operation instruction information set to directly respond to the DNS request.

[0258] Optionally, the processor is configured to read the computer program in the memory and perform the following operations:

[0259] Sending sixth information to the EASDF of the VPLMN; the sixth information includes information for constructing an EDNS client subnet option; or, the sixth information includes information of a local DNS server associated with a public DNAI.

[0260] Optionally, the processor is configured to read the computer program in the memory and perform the following operations:

[0261] Sending a first subscription message to the NEF of the VPLMN and / or the NEF of the HPLMN, where the first subscription message is used to subscribe to a notification message of the AF traffic impact request information;

[0262] Receiving a first notification message sent by the NEF of the VPLMN and / or the NEF of the HPLMN;

[0263] The first notification message includes at least one of the following information:

[0264] Traffic correlation identification;

[0265] EAS relevance indication;

[0266] Traffic correlation indication;

[0267] The IP address of the public EAS;

[0268] Public DNAI;

[0269] FQDN;

[0270] Information about NEF.

[0271] An embodiment of the present application provides a network device, including: a memory, a transceiver, and a processor:

[0272] A memory for storing a computer program; a transceiver for receiving and sending data under the control of the processor; and a processor for reading the computer program in the memory and performing the following operations:

[0273] Receiving a first subscription message sent by the SMF of the VPLMN, where the first subscription message is used to subscribe to a notification message of AF traffic impact request information;

[0274] Sending a first notification message to the SMF of the VPLMN;

[0275] The first notification message includes at least one of the following information:

[0276] Traffic correlation identification;

[0277] EAS relevance indication;

[0278] Traffic correlation indication;

[0279] The IP address of the public EAS;

[0280] Public DNAI;

[0281] FQDN;

[0282] Information about NEF.

[0283] Optionally, the processor is configured to read the computer program in the memory and perform the following operations:

[0284] Sending a second subscription message to the UDR of the VPLMN, where the second subscription message is used to subscribe to a notification message of the AF traffic impact request information;

[0285] receiving a second notification message sent by the UDR of the VPLMN;

[0286] When it is determined according to the second notification message that the terminal affected by the AF request is a roaming terminal, sending the first notification message to the SMF of the VPLMN;

[0287] The second notification message includes at least one of the following:

[0288] Traffic correlation identification;

[0289] EAS relevance indication;

[0290] Traffic correlation indication;

[0291] The IP address of the public EAS;

[0292] Public DNAI;

[0293] FQDN;

[0294] Space validity conditions.

[0295] Optionally, the processor is configured to read the computer program in the memory and perform the following operations:

[0296] If the NEF of the VPLMN does not have the IP address or public DNAI of the public EAS associated with the traffic correlation identifier, a fourth request message is sent to the NEF of the HPLMN, where the fourth request message is used to request the IP address or public DNAI of the public EAS.

[0297] Optionally, the processor is configured to read the computer program in the memory and perform the following operations:

[0298] Receiving a second request message sent by the SMF of the VPLMN;

[0299] A public EAS is determined according to the second request message.

[0300] Optionally, the processor is configured to read the computer program in the memory and perform the following operations:

[0301] receiving a third request message sent by the SMF of the VPLMN;

[0302] A public DNAI is determined according to the third request message.

[0303] Optionally, the processor is configured to read the computer program in the memory and perform the following operations:

[0304] Receive the IP address of the public EAS sent by the SMF of the VPLMN, where the public EAS is discovered by the SMF of the VPLMN.

[0305] An embodiment of the present application provides a network device, including: a memory, a transceiver, and a processor:

[0306] A memory for storing a computer program; a transceiver for receiving and sending data under the control of the processor; and a processor for reading the computer program in the memory and performing the following operations:

[0307] Sending a first request message to a target network element of the VPLMN;

[0308] The first request message includes at least one of the following information:

[0309] Terminal identification;

[0310] EAS relevance indication;

[0311] Traffic correlation identification;

[0312] Traffic correlation indication;

[0313] Application information;

[0314] The IP address or the candidate public DNAI of the candidate public EAS selected by the AF for the terminal.

[0315] Optionally, the processor is configured to read the computer program in the memory and perform the following operations:

[0316] Receive candidate DNAI sent by SMF;

[0317] According to the candidate DNAI, a candidate public EAS or a candidate public DNAI is selected for the terminal.

[0318] Optionally, the processor is configured to read the computer program in the memory and perform at least one of the following operations:

[0319] Sending the first request message to the SMF of the VPLMN through the NEF and / or UDR of the VPLMN;

[0320] The first request message is sent to the PCF of the VPLMN through the NEF and / or UDR of the VPLMN, so that the PCF of the VPLMN generates a PCC rule according to the first request message and sends the PCC rule to the SMF of the VPLMN.

[0321] Optionally, the application information includes at least one of the following:

[0322] At least one FQDN;

[0323] At least one EAS IP address.

[0324] An embodiment of the present application provides a network device, including: a memory, a transceiver, and a processor:

[0325] A memory for storing a computer program; a transceiver for receiving and sending data under the control of the processor; and a processor for reading the computer program in the memory and performing the following operations:

[0326] receiving a first request message;

[0327] generating a PCC rule according to the first request message;

[0328] Sending the PCC rules to the SMF of the VPLMN;

[0329] The first request message includes at least one of the following information:

[0330] Terminal identification;

[0331] EAS relevance indication;

[0332] Traffic correlation identification;

[0333] Traffic correlation indication;

[0334] Application information;

[0335] The IP address or the candidate public DNAI of the candidate public EAS selected by the AF for the terminal.

[0336] The PCC rule includes at least one of the following information:

[0337] Traffic correlation identification;

[0338] EAS relevance indication;

[0339] Application information;

[0340] The IP address or the candidate public DNAI of the candidate public EAS selected by the AF for the terminal.

[0341] Optionally, the processor is configured to read the computer program in the memory and perform the following operations:

[0342] Receive a first request message sent by the NEF and / or UDR of the VPLMN.

[0343] Optionally, the application information includes at least one of the following:

[0344] At least one FQDN;

[0345] At least one EAS IP address.

[0346] An embodiment of the present application provides a device for discovering an edge application server, including:

[0347] A first determination unit, configured to determine whether the traffic of the application supports routing to the local DN of the VPLMN;

[0348] A second determining unit is configured to determine, if the traffic of the application supports routing to the local DN of the VPLMN, to select a public edge application server EAS deployed in the VPLMN or a public data network access identifier DNAI for accessing the VPLMN for the terminal;

[0349] If the traffic of the application does not support routing to the local DN of the VPLMN, it is determined that a public EAS deployed in the home public land mobile network HPLMN or a public DNAI for accessing the HPLMN is selected for the terminal.

[0350] An embodiment of the present application provides a device for discovering an edge application server, including:

[0351] A third receiving unit is used to receive a first subscription message sent by the SMF of the VPLMN, where the first subscription message is used to subscribe to a notification message of the AF traffic impact request information;

[0352] A seventh sending unit, configured to send a first notification message to the SMF of the VPLMN;

[0353] The first notification message includes at least one of the following information:

[0354] Traffic correlation identification;

[0355] EAS relevance indication;

[0356] Traffic correlation indication;

[0357] The IP address of the public EAS;

[0358] Public DNAI;

[0359] FQDN;

[0360] Information about NEF.

[0361] An embodiment of the present application provides a discovery device for an edge application server, including:

[0362] A first sending unit, configured to send a first request message to a target network element of the VPLMN;

[0363] The first request message includes at least one of the following information:

[0364] Terminal identification;

[0365] EAS relevance indication;

[0366] Traffic correlation identification;

[0367] Traffic correlation indication;

[0368] Application information;

[0369] The IP address or the candidate public DNAI of the candidate public EAS selected by the AF for the terminal.

[0370] An embodiment of the present application provides a discovery device for an edge application server, including:

[0371] A first receiving unit, configured to receive a first request message;

[0372] A generating unit, configured to generate a PCC rule according to the first request message;

[0373] A second sending unit, configured to send the PCC rule to the SMF of the VPLMN;

[0374] The first request message includes at least one of the following information:

[0375] Terminal identification;

[0376] EAS relevance indication;

[0377] Traffic correlation identification;

[0378] Traffic correlation indication;

[0379] Application information;

[0380] The IP address or the candidate public DNAI of the candidate public EAS selected by the AF for the terminal.

[0381] The PCC rule includes at least one of the following information:

[0382] Traffic correlation identification;

[0383] EAS relevance indication;

[0384] Application information;

[0385] The IP address or the candidate public DNAI of the candidate public EAS selected by the AF for the terminal.

[0386] An embodiment of the present application provides a processor-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps of the above-mentioned method for discovering an edge application server are implemented.

[0387] The beneficial effects of the above technical solution of the present application are:

[0388] In an embodiment of the present application, the SMF determines whether the traffic of the application to be used by the terminal supports routing to the local DN of the VPLMN, thereby selecting a public EAS or public DNAI deployed in the VPLMN for the terminal, or selecting a public EAS or public DNAI deployed in the HPLMN, thereby enabling selection of a suitable public EAS or public DNAI for the terminal. BRIEF DESCRIPTION OF THE DRAWINGS

[0389] Figure 1 A schematic diagram showing the network architecture of edge computing;

[0390] Figure 2 A flowchart of a method for discovering an edge application server according to an embodiment of the present application is shown;

[0391] Figure 3 A second flowchart of the method for discovering an edge application server according to an embodiment of the present application is shown;

[0392] Figure 4 A third flowchart of the method for discovering an edge application server according to an embodiment of the present application is shown;

[0393] Figure 5 A fourth flowchart of the method for discovering an edge application server according to an embodiment of the present application;

[0394] Figure 6a and Figure 6b A fifth flowchart of the method for discovering an edge application server according to an embodiment of the present application is shown;

[0395] Figure 7 A sixth flowchart of a method for discovering an edge application server according to an embodiment of the present application;

[0396] Figure 8 A seventh flowchart of a method for discovering an edge application server according to an embodiment of the present application;

[0397] Fig. 9 One of the structural schematic diagrams showing the discovery device of the edge application server in the embodiment of the present application;

[0398] Fig.10 A second structural diagram showing a discovery device of an edge application server according to an embodiment of the present application;

[0399] Fig.11 A third structural diagram showing a discovery device of an edge application server according to an embodiment of the present application;

[0400] Fig.12 One of the structural schematic diagrams of the network device according to the embodiment of the present application is shown;

[0401] Fig.13A second structural diagram of a network device according to an embodiment of the present application;

[0402] Fig.14 The third structural diagram of the network device according to the embodiment of the present application. DETAILED DESCRIPTION

[0403] In order to make the technical problems, technical solutions and advantages to be solved by the application clearer, the following will be described in detail in conjunction with the accompanying drawings and specific embodiments. In the following description, specific details such as specific configurations and components are provided only to help fully understand the embodiments of the application. Therefore, it should be clear to those skilled in the art that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the application. In addition, for clarity and brevity, the description of known functions and structures has been omitted.

[0404] It should be understood that the references to "one embodiment" or "an embodiment" throughout the specification mean that the specific features, structures, or characteristics associated with the embodiment are included in at least one embodiment of the present application. Therefore, the references to "in one embodiment" or "in an embodiment" appearing throughout the specification do not necessarily refer to the same embodiment. In addition, these specific features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0405] In the various embodiments of the present application, it should be understood that the size of the serial numbers of the following processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0406] In the embodiments of the present application, the term "and / or" describes the association relationship of the associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the associated objects before and after are in an "or" relationship.

[0407] In the embodiments of the present application, the term "plurality" refers to two or more than two, and other quantifiers are similar.

[0408] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0409] When describing the embodiments of the present application, some concepts used in the following description are first explained.

[0410] 1. Mobile Edge Computing

[0411] MEC technology migrates computing storage and business service capabilities to the edge of the network, avoiding the need to transmit data back to the cloud as much as possible, reducing the waiting time and network costs of data going back and forth between the cloud and the cloud. Based on the 5G distributed cloud infrastructure, 5G user planes and 5G MEC nodes are built on the edge cloud. 5G MEC nodes provide MEC application platforms to implement the deployment and management capabilities of third-party applications. Users can obtain services through MEC applications.

[0412] The network architecture of edge computing is as follows: Figure 1 The figure shows the network architecture diagram for accessing the edge computing server in a roaming scenario.

[0413] 5G defines an application function (AF), which sends an AF request to a non-trusted domain (such as a network exposure function (NEF)) or to a trusted domain (such as a policy control function entity (PCF)), which contains a series of parameters such as the target data network name (DNN), application identifier (ID), N6 routing requirements, and application location. Based on the information parameters provided by AF and combined with its own policy control, PCF generates PCC rules for the target protocol data unit (PDU) session service flow and selects a suitable user plane function (UPF) for it through SMF. MEC provides functions such as application infrastructure resource orchestration, application instantiation, and application rule configuration. Therefore, when MEC is deployed in a 5G system, MEC can also act as an AF to interact with the 5G system control plane on behalf of the applications deployed on MEC.

[0414] Among them, Figure 1 The main network functions in the shown architecture are described as follows:

[0415] AMF: used for registration, connection management, etc.

[0416] UPF: An external PDU session node interconnected with the data network, performing message routing and forwarding.

[0417] SMF: used for session establishment, deletion, user plane selection and control, UE IP allocation, etc.

[0418] AF: Interacts with the core network to provide services. Based on the operator's deployment, a trusted AF can interact directly with the relevant network function (NF), while an untrusted AF cannot interact directly with the NF, but should use an open framework through the NEF.

[0419] PCF: Supports a unified policy framework to manage network behavior and provide policy rules for control plane NF execution.

[0420] NRF: Supports service discovery function.

[0421] Unified Data Management (UDM): stores UE information, such as subscription information and information about established PDU sessions.

[0422] NEF: securely exposes the services and capabilities provided by the network to external network-related functions.

[0423] UDR: used for storage of contract data, retrieval of contract data by UDM FE, storage of policy information, and retrieval of policy information by PCF.

[0424] EASDF: used to process DNS messages based on SMF instructions.

[0425] EAS: Provides edge services.

[0426] Local DN (Local part of DN): L-DN for short. It refers to a set of network entities deployed in a local data network. Local access DN provides access to the local part of DN.

[0427] In order to support selective data routing to DN, SMF can control the data path of PDU session to ensure that PDU session can correspond to multiple N6 interfaces at the same time. Each anchor point supporting PDU session provides different access paths to the same DN to achieve local diversion. It can be achieved through the uplink classifier (UL CL) function and the IPv6 multi-homing function branching point (BP). This architecture is called the session breakout connection model.

[0428] When UE roams, the UE establishes a Home Routed (HR) session based on the subscription that supports session breakout to the VPLMN. In this scenario, there is a protocol between the Home PLMN and the Visited PLMN that supports local routing of HomeRouted sessions in the VPLMN. When a Home Routed Session Breakout (HR-SBO) PDU session is established, the UE can access the EAS deployed in the Edge Hosting Environment (EHE) in the VPLMN, and can also access the data network in the Home PLMN.

[0429] There are some application scenarios that need to support the selection of common DNAI or common EAS for a UE group. The scenario examples are as follows:

[0430] Interactive multi-user gaming: Different UEs that can be identified by the application, for example, UEs in a geographical area, need to access the same gaming service for interaction. The UEs need to connect to the same application server, or an application server associated with the same DNAI, or an application server belonging to the same L-DN, to reduce the latency of the interaction on the application server side.

[0431] Online conference: It is impossible to determine in advance which electronic conference (e-meeting) different UEs will access. If UEs accessing the same conference access the same e-meeting server, the interaction delay on the application server side can be reduced, and the communication volume between application servers can also be reduced, which will greatly reduce costs.

[0432] This group of UEs may be in a roaming state or a non-roaming state.

[0433] The embodiments of the present application provide a method and device for discovering an edge application server, so as to solve the problem that a suitable edge application server cannot be selected for a roaming UE.

[0434] Among them, the method and the device are based on the same application concept. Since the method and the device solve the problem in a similar principle, the implementation of the device and the method can refer to each other, and the repeated parts will not be repeated.

[0435] like Figure 2 As shown, an embodiment of the present application provides a method for discovering an edge application server, which is executed by a session management function SMF and specifically includes the following steps:

[0436] Step 201: Determine whether the traffic of the application supports routing to the local data network DN of the visited public land mobile network VPLMN.

[0437] Step 202: If the traffic of the application supports routing to the local DN of the VPLMN, it is determined that the public edge application server EAS deployed in the VPLMN or the public data network access identifier DNAI for accessing the VPLMN is selected for the terminal;

[0438] If the traffic of the application does not support routing to the local DN of the VPLMN, it is determined that a public EAS deployed in the home public land mobile network HPLMN or a public DNAI for accessing the HPLMN is selected for the terminal.

[0439] In this embodiment, the SMF may be the SMF of the VPLMN (which may be denoted as V-SMF) or the SMF of the HPLMN (which may be denoted as H-SMF), that is, it may determine through the VPLMN network or the HPLMN network whether the traffic of the application supports routing to the local DN of the VPLMN. The application is the application to be used by the terminal, and the SMF determines whether the traffic of the application supports routing to the local DN of the VPLMN. If it supports, a public EAS or public DNAI deployed in the VPLMN may be selected for the terminal, that is, the terminal may use the application deployed in the local DN of the VPLMN; if it does not support, a public EAS or public DNAI deployed in the HPLMN may be selected for the terminal, and the terminal may use the application deployed in the HPLMN.

[0440] The terminal may be a roaming terminal, and the terminal may be any one of a group of terminals using a specific application, the group of terminals using a specific application being in a roaming state, that is, the terminal is a terminal that establishes an HR session or an HR-SBO session.

[0441] In an embodiment of the present application, the SMF determines whether the traffic of the application to be used by the terminal supports routing to the local DN of the VPLMN, thereby selecting a public EAS or public DNAI deployed in the VPLMN for the terminal, or selecting a public EAS or public DNAI deployed in the HPLMN, thereby enabling selection of a suitable public EAS or public DNAI for the terminal.

[0442] As an optional embodiment, the determining whether the traffic of the application supports routing to the local DN of the visited public land mobile network VPLMN includes:

[0443] Determining, according to the received first information, whether the traffic of the application supports routing to the local DN of the VPLMN;

[0444] The first information is: a policy and charging control PCC rule sent by a policy control function entity PCF or a first request message sent by an application function AF; or, the first information is: a DNS query request sent by a terminal. The SMF can determine whether the traffic of the application supports routing to the local DN of the VPLMN based on the content carried in the DNS query request sent by the terminal, or the SMF can determine whether the traffic of the application is allowed to be routed through HR-SBO based on the content carried in the DNS query request sent by the terminal. For example: determine whether the traffic of the application supports routing to the local DN of the VPLMN based on the FQDN carried in the DNS query request.

[0445] Optionally, the PCC rule includes at least one of the following information:

[0446] Traffic Correlation ID;

[0447] EAS Correlation indication;

[0448] Application information, such as at least one fully qualified domain name FQDN and / or at least one IP address of an EAS;

[0449] The Internet Protocol IP address or the candidate public DNAI of the candidate public EAS selected by the AF for the terminal.

[0450] In this embodiment, the AF can determine the public EAS or public DNAI that needs to be accessed for a group of UEs using a specific application. The SMF can determine the candidate public DNAI based on the location of the terminal, multiple available DNAIs, VPLMN offloading information, EAS deployment information, and other information, and send the candidate public DNAI to the AF; the AF can select the candidate public EAS or candidate public DNAI for the terminal based on the candidate public DNAI.

[0451] Optionally, the first request message includes at least one of the following information:

[0452] Terminal Identifier (UE Identifier);

[0453] EAS Correlation indication;

[0454] Traffic Correlation ID;

[0455] Traffic correlation indication (EAS Correlation indication);

[0456] Application information; such as at least one fully qualified domain name FQDN and / or at least one EAS IP address;

[0457] The IP address or the candidate public DNAI of the candidate public EAS selected by the AF for the terminal.

[0458] In this embodiment, the AF requests to select a common EAS or a common DNAI for a group of UEs using a specific application, wherein the AF can send a first request message to the PCF, and the PCF generates a PCC rule based on the request of the AF, and can send the PCC rule to the SMF, and the SMF determines whether the traffic of the application supports routing to the local DN of the VPLMN according to the PCC rule.

[0459] It should be noted that if AF sends the first request message to H-PCF (i.e., the PCF of HPLMN), then after H-PCF generates the PCC rules, it can send the PCC rules to H-SMF. If H-SMF determines that the traffic of the application supports routing to the local DN of VPLMN, H-SMF needs to send the relevant content in the first request message to V-SMF.

[0460] AF can also send the first request message to V-PCF (i.e., the PCF of VPLMN). After V-PCF generates the PCC rules, it can send the PCC rules to V-SMF. If V-SMF determines that the traffic of the application does not support routing to the local DN of VPLMN, V-SMF needs to send the relevant content in the request message to H-SMF.

[0461] Alternatively, the AF may directly send the first request message to the V-SMF, and the V-SMF determines whether the traffic of the application supports routing to the local DN of the VPLMN according to the PCC rule.

[0462] As an optional embodiment, determining, according to the received first information, whether the traffic of the application supports routing to the local DN of the VPLMN includes at least one of the following:

[0463] Mode 1: In the case where the first information includes application information, if the application information included in the first information allows being routed to the local DN of the VPLMN, it is determined that the traffic of the application supports being routed to the local DN of the VPLMN; if the application information included in the first information does not allow being routed to the local DN of the VPLMN, it is determined that the traffic of the application does not support being routed to the local DN of the VPLMN;

[0464] or,

[0465] Method 2: When the first information includes application information and the IP address of the candidate public EAS or the candidate public DNAI selected by the AF for the terminal, if the candidate public EAS is deployed in the VPLMN or the candidate public DNAI is used to access the VPLMN, and the application information and the candidate public EAS or the candidate public DNAI included in the first information are allowed to be routed to the local DN of the VPLMN, it is determined that the traffic of the application supports routing to the local DN of the VPLMN; if the candidate public EAS is deployed in the VPLMN or the candidate public DNAI is used to access the VPLMN, and the application information and the candidate public EAS or the candidate public DNAI included in the first information are not allowed to be routed to the local DN of the VPLMN, it is determined that the traffic of the application does not support routing to the local DN of the VPLMN.

[0466] Optionally, the application information includes at least one of the following:

[0467] At least one fully qualified domain name (FQDN);

[0468] At least one EAS IP address.

[0469] In this embodiment, the SMF determines whether the traffic of the application supports routing to the local DN of the VPLMN according to the first information, which may include the above two methods. The two methods are described below respectively.

[0470] For method 1: Taking the first information as a PCC rule as an example, if the SMF determines that the application information contained in the PCC rule contains an FQDN, and the FQDN is allowed to be routed to the local DN of the VPLMN, it is determined that the application traffic supports routing to the local DN of the VPLMN, that is, it is determined that the public EAS deployed in the VPLMN or the public DNAI for accessing the VPLMN can be selected for the terminal. If the SMF determines that the FQDN in the application information contained in the PCC rule is not allowed to be routed to the local DN of the VPLMN, it is determined that the application traffic does not support routing to the local DN of the VPLMN, that is, it is determined that the public EAS deployed in the HPLMN or the public DNAI for accessing the HPLMN can be selected for the terminal.

[0471] Taking the first information being the first request message as an example, if the SMF determines that the application information contained in the first request message includes an FQDN, and the FQDN is allowed to be routed to the local DN of the VPLMN, then it is determined that the application traffic supports routing to the local DN of the VPLMN, that is, it is determined that a public EAS deployed in the VPLMN or a public DNAI for accessing the VPLMN can be selected for the terminal. If the SMF determines that the FQDN in the application information contained in the first request message is not allowed to be routed to the local DN of the VPLMN, then it is determined that the application traffic does not support routing to the local DN of the VPLMN, that is, it is determined that a public EAS deployed in the HPLMN or a public DNAI for accessing the HPLMN can be selected for the terminal.

[0472] For method 2: taking the application information including FQDN as an example, if the PCC rule sent by the PCF or the first request message contains the IP address or candidate public DNAI of the candidate public EAS selected by the AF for the terminal, and the candidate public EAS is deployed in the VPLMN or the candidate public DNAI is used to access the local DN of the VPLMN, and the FQDN or candidate public EAS or candidate public DNAI contained in the first information is allowed to be routed to the local DN of the VPLMN, then it can be determined that the application traffic supports routing to the local DN of the VPLMN.

[0473] If the candidate public EAS contained in the first message is deployed in the VPLMN or the candidate public DNAI is used to access the VPLMN, but the application information contained in the first message and the candidate public EAS or the candidate public DNAI are not allowed to be routed to the local DN of the VPLMN, it is determined that the traffic of the application does not support routing to the local DN of the VPLMN, that is, it is determined that a public EAS deployed in the HPLMN or a public DNAI for accessing the HPLMN needs to be selected for the terminal.

[0474] Optionally, in the above-mentioned method 1 and method 2, the application information included in the first information is allowed to be routed to the local DN of the VPLMN, including: the application information in the VPLMN offload information includes the application information in the first information.

[0475] For example: the above application information includes FQDN, and the FQDN in the VPLMN Specific Offloading Information includes the FQDN in the first information (such as the PCC rule or the first request message), and it is considered that the application information included in the first information is allowed to be routed to the local DN of the VPLMN. On the contrary, the FQDN in the VPLMN Specific Offloading Information does not include the FQDN in the first information (such as the PCC rule or the first request message), and it is considered that the application information included in the first information is not allowed to be routed to the local DN of the VPLMN.

[0476] The candidate public EAS or candidate public DNAI is allowed to be routed to the local DN of the VPLMN, including: the IP range in the VPLMN offload information includes the IP address of the candidate public EAS.

[0477] For example, if the IP range in the VPLMN Specific Offloading Information contains the IP address of the Common EAS, it is considered that the candidate public EAS or candidate public DNAI is allowed to be routed to the local DN of the VPLMN. On the contrary, if the IP range in the VPLMN Specific Offloading Information does not contain the IP address of the Common EAS, it is considered that the candidate public EAS or candidate public DNAI is not allowed to be routed to the local DN of the VPLMN.

[0478] As an optional embodiment, the method further includes:

[0479] In the case where the first information includes the IP address of the candidate public EAS or the candidate public DNAI selected by the AF for the terminal, if it is determined that the traffic of the application supports routing to the local DN of the VPLMN, then determining the candidate public EAS or the candidate public DNAI as the public EAS or public DNAI of the terminal;

[0480] When the first information includes the IP address of the candidate public EAS or the candidate public DNAI selected by the AF for the terminal, if it is determined that the traffic of the application does not support routing to the local DN of the VPLMN, a public EAS deployed in the HPLMN or a public DNAI for accessing the HPLMN is reselected for the terminal.

[0481] In this embodiment, if the AF selects a candidate public EAS or a candidate public DNAI for the terminal and is able to determine that the application traffic supports routing to the local DN of the VPLMN, the candidate public EAS or candidate public DNAI selected by the AF can be used as the public EAS or public DNAI finally selected for the terminal; if it is determined that the application traffic does not support routing to the local DN of the VPLMN, the candidate public EAS or candidate public DNAI selected by the AF cannot be used as the public EAS or public DNAI of the terminal, and it is necessary to reselect a public EAS deployed in the HPLMN or a public DNAI for accessing the HPLMN for the terminal.

[0482] Optionally, the determining, according to the received first information, whether the traffic branch of the application supports routing to the local DN of the VPLMN further includes:

[0483] In the case where the first information includes the IP address or candidate public DNAI of the candidate public EAS selected by the AF for the terminal, if the candidate public EAS is deployed in the HPLMN or the candidate public DNAI is used to access the HPLMN, it is determined that the traffic of the application does not support routing to the local DN of the VPLMN.

[0484] In this embodiment, if the candidate public EAS selected by the AF for the terminal is deployed in the HPLMN, or the candidate public DNAI is used to access the HPLMN, it can be determined that the application traffic does not support routing to the local DN of the VPLMN, that is, the terminal cannot use the service deployed locally in the VPLMN.

[0485] As an optional embodiment, the method further includes:

[0486] If the SMF is the SMF of the HPLMN, and the traffic of the application supports routing to the local DN of the VPLMN, sending the second information to the SMF of the VPLMN;

[0487] The second information includes at least one of the following:

[0488] EAS relevance indication;

[0489] Traffic correlation identification;

[0490] Application information;

[0491] The IP address or the candidate public DNAI of the candidate public EAS selected by the AF for the terminal.

[0492] In this embodiment, if it is determined that the traffic of the application supports routing to the local DN of the VPLMN, it is necessary to select a public EAS deployed in the VPLMN or a public DNAI for accessing the VPLMN for the terminal. The terminal uses the local services of the VPLMN, so after the H-SMF determines that the traffic of the application supports routing to the local DN of the VPLMN, it is necessary to send relevant information to the V-SMF, such as one or more of the EAS correlation indication, traffic correlation identifier, FQDN, EAS IP address, AF selected candidate public EAS IP address or candidate public DNAI, etc.

[0493] As an optional embodiment, the method further includes:

[0494] If the SMF is the SMF of the VPLMN, and the traffic of the application does not support routing to the local DN of the VPLMN, sending third information to the SMF of the HPLMN;

[0495] The third information includes at least one of the following:

[0496] EAS relevance indication;

[0497] Traffic correlation identification;

[0498] Application information.

[0499] In this embodiment, if the V-SMF determines that the traffic of the application does not support routing to the local DN of the VPLMN, it is necessary to select a public EAS or public DNAI deployed in the HPLMN for the terminal, and the network element of the HPLMN needs to perform relevant operations. The V-SMF sends relevant information to the H-SMF, such as one or more of the EAS correlation indication, traffic correlation identifier, FQDN, etc.

[0500] As an optional embodiment, the method further includes:

[0501] If the SMF is the SMF of the VPLMN, and it is determined that a public EAS deployed in the VPLMN or a public DNAI for accessing the VPLMN is selected for the terminal, a domain name system DNS message processing rule is sent to the edge application server discovery function EASDF of the VPLMN;

[0502] The DNS message processing rule is used to indicate: when the application information contained in the DNS query meets the application information range configured by the SMF of the VPLMN, select a public EAS deployed in the VPLMN or a public DNAI for accessing the VPLMN for the terminal.

[0503] In this embodiment, for the discovery process of the edge application server, if the V-SMF determines to select the public EAS deployed in the VPLMN or the public DNAI for accessing the VPLMN, the V-SMF also needs to configure the DNS message handling rule to the V-EASDF, and the message handling rule is used to indicate that when the FQDN contained in the DNS query satisfies the application information configured by the V-SMF, the common EAS deployed in the VPLMN can be selected. Alternatively, the common DNAI of the local DN for accessing the VPLMN is selected through the local LDS server (Local DNS Server) / resolver (Resolver) or V-EASDF.

[0504] The application information contained in the DNS query satisfies the application information range configured by the SMF of the VPLMN. For example, the FQDN contained in the DNS query satisfies the FQDN range configured by the V-SMF, that is, the FQDN contained in the DNS query is the FQDN(s) contained in both the VPLMN specific offloading information (Specific Offloading Information) and the PCC rule.

[0505] As an optional embodiment, the method further includes: determining a candidate DNAI based on the fourth information; sending the candidate DNAI to the AF;

[0506] The fourth information includes at least one of the following:

[0507] Terminal location information (UE location);

[0508] Available DNAI information, such as a list of available DNAIs (DNAI list);

[0509] VPLMN Specific Offloading Information;

[0510] EAS deployment information (EASDeployment Information).

[0511] In this embodiment, the SMF may be an H-SMF or a V-SMF. The H-SMF or the V-SMF determines the candidate DNAI(s) based on the UE location, the available DNAI list provided by the AF, the VPLMN Specific Offloading Information, the EAS Deployment Information, etc., and sends them to the AF.

[0512] In an embodiment of the present application, for a roaming UE that establishes an HR / HR-SBO session, the core network determines whether the traffic of the application to be used by the UE supports routing to the local DN of the VPLMN through the interaction between the AF and the network elements of the HPLMN or the network elements of the VPLMN, thereby selecting a common EAS deployed in the VPLMN or HPLMN for the roaming UE, or selecting a suitable common DNAI.

[0513] As an optional embodiment, the determining whether the traffic of the application supports routing to the local DN of the visited public land mobile network VPLMN includes:

[0514] If it is determined that the FQDN carried in the DNS query request sent by the terminal is authorized by the SMF of the HPLMN, it is determined that the traffic of the application supports routing to the local DN of the VPLMN;

[0515] or,

[0516] If it is determined that the FQDN carried in the DNS query request sent by the terminal has not been authorized by the SMF of the HPLMN, it is determined that the traffic of the application does not support routing to the local DN of the VPLMN.

[0517] In this embodiment, if the V-SMF determines that the target FQDN in the DNS query request has been authorized by the H-SMF, it can be determined that the application traffic supports routing to the local DN of the VPLMN, indicating that access to the EAS deployed in the VPLMN is allowed. If the V-SMF determines that the FQDN in the DNS query request has not been authorized by the H-SMF, it can be determined that the application traffic does not support routing to the local DN of the VPLMN, that is, access to the EAS deployed in the VPLMN is not allowed, then the terminal can access the local DN deployed in the HPLMN.

[0518] Optionally, the determining that the terminal selects a public EAS deployed in a VPLMN or a public DNAI for accessing the VPLMN includes:

[0519] If the FQDN carried in the DNS query request sent by the terminal matches the FQDN sent by the NEF of the VPLMN, and is configured with an EAS correlation indication or a traffic correlation indication, it is determined that the terminal selects a public EAS deployed in the VPLMN or a public DNAI for accessing the VPLMN.

[0520] In this embodiment, the FQDN carried in the DNS query request sent by the terminal matches the FQDN sent by the NEF of the VPLMN, which may mean that the FQDN received from the V-NEF includes the FQDN carried in the DNS query request. And if the EAS Correlation indication or the indication of traffic correlation is set, the SMF determines that the UE identified by the Traffic Correlation ID requires a UE group, and for this UE group, it is necessary to connect to a common EAS or select a common DNAI.

[0521] Optionally, the method further includes:

[0522] Sending a first subscription message to the NEF of the VPLMN and / or the NEF of the HPLMN, where the first subscription message is used to subscribe to a notification message of AF traffic influence request information;

[0523] Receiving a first notification message sent by the NEF of the VPLMN and / or the NEF of the HPLMN;

[0524] The first notification message includes at least one of the following information:

[0525] Traffic correlation identification;

[0526] EAS relevance indication;

[0527] Traffic correlation indication;

[0528] The IP address of the public EAS;

[0529] Public DNAI;

[0530] FQDN;

[0531] Information about NEF.

[0532] In this embodiment, V-SMF subscribes to the notification message of AF traffic influence request information (AF traffic response request message) from V-NEF; V-NEF subscribes to the notification message of AF traffic influence request information from V-UDR. AF sends a request message requesting to select common EAS or common DNAI for a group of UEs accessing a specific application, and then V-UDR notifies the V-NEF that has subscribed to the AF traffic influence request information. V-NEF determines the UE affected by the AF request and provides the first notification message to the V-SMF that has subscribed to the AF traffic influence request information.

[0533] As an optional embodiment, in the case of determining that the traffic of the application supports routing to the local DN of the VPLMN, the method further includes:

[0534] If the notification message sent by the NEF of the VPLMN does not include the IP address of the public EAS, or the SMF of the VPLMN determines to select a new EAS for the terminal, the public EAS deployed in the VPLMN is discovered;

[0535] If the SMF of the VPLMN has an IP address of a public EAS, the IP address of the public EAS is determined as the public EAS deployed in the VPLMN selected for the terminal.

[0536] In this embodiment, if common EAS is not received from the notification information sent by V-NEF, or V-SMF decides to trigger the EAS discovery process to select a new EAS for the UE group, V-SMF can perform the process of discovering EAS, for example: V-SMF discovers common EAS based on the technology of discovering EAS through HR-SBO PDU session. If V-SMF itself has an available common EAS IP address, there is no need to perform the discovery process.

[0537] As an optional embodiment, when it is determined that the traffic of the application does not support routing to the local DN of the VPLMN, the method further includes:

[0538] If the notification message sent by the NEF of the VPLMN does not include the IP address of the public EAS, or the SMF of the VPLMN determines to select a new EAS for the terminal, at least one of the following is performed:

[0539] Discover the public EAS deployed in the HPLMN;

[0540] Sending fifth information to the SMF of the HPLMN, the fifth information being used to request the SMF of the HPLMN to discover a public EAS; the fifth information comprising at least one of an EAS correlation indication, a traffic correlation identifier, and an FQDN;

[0541] Sending a second request message to the NEF of the VPLMN and / or the NEF of the HPLMN, where the second request message is used to request the NEF to determine a common EAS;

[0542] If the SMF of the VPLMN has an IP address of a public EAS, the IP address of the public EAS is determined as the public EAS deployed in the HPLMN selected for the terminal.

[0543] In this embodiment, if common EAS is not received from the notification information sent by V-NEF, or V-SMF decides to trigger the EAS discovery process to select a new EAS for the UE group, V-SMF can perform the process of discovering EAS to discover the public EAS deployed in the HPLMN. And / or, V-SMF can also send the fifth information to the SMF of the HPLMN, so that H-SMF performs the process of discovering the public EAS deployed in the HPLMN. Among them, V-SMF can send the fifth information through the Nsmf_PDU session status notification request (Nsmf_PDUSession_StatusNotify request). The fifth information includes: one or more of EASCorrelation indication, Traffic Correlation ID, and FQDN. H-SMF can discover common EAS based on the technology of discovering EAS through HR-SBO PDU session. And / or, V-SMF can request NEF to determine the common EAS IP address.

[0544] If V-SMF itself has an available common EAS IP address, there is no need to perform the discovery process.

[0545] Optionally, the method further includes: sending the IP address of the public EAS to the NEF of the VPLMN and / or the NEF of the HPLMN.

[0546] In this embodiment, after the SMF obtains the IP address of the EAS, it may also perform a common EAS IP coordination process, and the SMF provides the new common EAS IP address to the NEF (V-NEF or H-NEF).

[0547] Optionally, in the case where traffic of the application supports routing to a local DN of a VPLMN, the method further includes:

[0548] If the notification message sent by the NEF of the VPLMN does not include the public DNAI, a third request message is sent to the NEF of the VPLMN, where the third request message is used to request the NEF of the VPLMN to determine the public DNAI.

[0549] In this embodiment, if the common DNAI is not received from the notification information sent by the V-NEF, the V-SMF may request the NEF to determine the common DNAI.

[0550] Optionally, the method further includes: determining a DNAI based on the public EAS. In this embodiment, if the V-SMF determines a public EAS for the terminal, the DNAI may also be determined based on the public EAS.

[0551] Optionally, the method further includes:

[0552] Send a DNS message processing rule to the EASDF of the VPLMN, wherein the DNS message processing rule is used to instruct the EASDF of the VPLMN to send the IP address of the public EAS to the terminal; wherein the DNS message processing rule includes: the public EAS IP address and forwarding operation indication information set to directly respond to the DNS request (Respond directly to the DNS request).

[0553] In this embodiment, the V-SMF may send a DNS message handling rule including a common EAS IP address and setting the forwarding action (Forwarding Action) to "Respond directly to the DNS request" to the V-EASDF to instruct the V-EASDF to directly reply the common EAS IP address to the UE via a DNS response.

[0554] Optionally, the method further includes: sending sixth information to the EASDF of the VPLMN; the sixth information includes information for constructing an EDNS client subnet option (EDNS Client Subnet option); or, the sixth information includes information of a local DNS server (Local DNS server) related to the public DNAI.

[0555] In this embodiment, when the common DNAI is determined, the V-SMF may provide the V-EASDF with information for constructing an EDNS Client Subnet option, where the EDNS Client Subnet option indicates a location that is topologically close to the common DNAI. Alternatively, the V-SMF provides the V-EASDF with a Local DNS server associated with the common DNAI.

[0556] The following describes the implementation process of the discovery method of the edge application server with examples for the network element interaction between the AF and the HPLMN and the network element interaction between the AF and the VPLMN.

[0557] As an optional embodiment, AF provides EAS Correlation indication, Traffic Correlation ID and other information by interacting with HPLMN. 5GC determines whether the traffic of the application to be used by the UE supports routing to the local DN of the VPLMN, and selects common EAS / common DNAI for the roaming UE based on the information provided by AF.

[0558] like Figure 3 As shown, the method includes:

[0559] Step 30: The roaming UE establishes a HR / HR-SBO session.

[0560] Step 31. The AF requests the selection of common EAS / common DNAI for a group of UEs using a specific application, and sends information such as UE Identifier(s), EAS Correlation indication, Traffic CorrelationID, indication of traffic correlation, FQDN(s) to the H-PCF through the H-NEF and H-UDR.

[0561] Step 32: The H-PCF generates a PCC rule based on the request of the AF, wherein the PCC rule includes parameters such as TrafficCorrelation ID, EAS Correlation indication, FQDN(s), etc. Optionally, it may be sent to the H-SMF via the Npcf_SM Policy Control_Update Notify service operation.

[0562] Step 33: Based on the PCC rule, the H-SMF determines that the UE belongs to the UE group identified by the Traffic Correlation ID, and this UE group needs to access the common EAS / common DNAI.

[0563] Step 33a. If the H-SMF determines that the FQDN included in the PCC rule is allowed to be routed to the local DN of the VPLMN (for example, the FQDN in the VPLMN Specific Offloading Information includes the FQDN in the PCC), it is determined that the common EAS deployed in the VPLMN can be selected or the common DNAI used to access the VPLMN can be selected. The H-SMF sends information such as EAS Correlation indication, Traffic Correlation ID, and FQDN to the V-SMF. Optionally, the H-SMF can send the above information values ​​to the V-SMF via an Nsmf_PDU session update request (Nsmf_PDUSession_Update request) or an Nsmf_PDU session status notification request (Nsmf_PDUSession_StatusNotify request) message.

[0564] Step 33b: If the H-SMF determines that the FQDN included in the PCC rule is not allowed to be routed to the local DN of the VPLMN (for example, the FQDN in the VPLMN Specific Offloading Information does not include the FQDN in the PCC), it is determined that the common EAS deployed in the HPLMN or the common DNAI for accessing the HPLMN can be selected.

[0565] Step 34a, if step 33a is executed, V-SMF configures a DNS message handling rule to V-EASDF, indicating that when the FQDN contained in the DNS query meets the FQDN range configured by V-SMF, the common EAS deployed in the VPLMN is selected based on the existing technology. Alternatively, the common DNAI of the local DN accessing the VPLMN is selected through the Local DNS Server / Resolver or V-EASDF.

[0566] Step 34b: If step 33b is executed, the H-SMF selects the commonEAS deployed in the HPLMN based on the existing technology, or selects the common DNAI of the DN accessed to the HPLMN.

[0567] As another optional embodiment, AF provides information such as EAS Correlation indication and Traffic Correlation ID by interacting with the network elements of the VPLMN. The 5GC determines whether the traffic of the application to be used by the UE supports routing to the local DN of the VPLMN, and selects common EAS / common DNAI for the roaming UE based on the information provided by the AF.

[0568] like Figure 4 As shown, the method includes:

[0569] Step 40: The roaming UE establishes a HR or HR-SBO session.

[0570] Step 41a. Optionally, the AF requests the selection of common EAS or commonDNAI for a group of UEs using a specific application, and may send information such as UE Identifier(s), EAS Correlation indication, Traffic Correlation ID, indication of traffic correlation, FQDN(s) to the V-SMF through V-NEF and V-UDR.

[0571] Step 41b, optionally, AF requests to select common EAS or commonDNAI for a group of UEs using a specific application, and sends UE Identifier(s), EAS Correlation indication, TrafficCorrelation ID, FQDN(s) and other information to V-PCF through V-NEF and V-UDR. Based on the AF request, V-PCF generates PCC rules including TrafficCorrelation ID, EAS Correlation indication, FQDN(s), and sends the PCC rules to V-SMF.

[0572] Step 42: V-SMF determines that the UE belongs to the UE group identified by the Traffic Correlation ID, and this UE group needs to access the common EAS / common DNAI.

[0573] Specifically, step 42 may include:

[0574] Step 42a: If the V-SMF determines that the FQDN received in step 41 is allowed to be routed to the local DN of the VPLMN, it is determined that the common EAS deployed in the VPLMN can be selected or the common DNAI can be selected to access the local DN of the VPLMN.

[0575] Step 42b: If the V-SMF determines that the FQDN received in step 41 is not allowed to be routed to the local DN of the VPLMN, it determines to select the common EAS deployed in the HPLMN or select the common DNAI to access the DN of the HPLMN.

[0576] V-SMF can send EAS Correlation indication, Traffic Correlation ID, FQDN and other information to H-SMF through Nsmf_PDUSession_Update request or Nsmf_PDUSession_StatusNotify request.

[0577] Step 43a: If step 42a is executed, V-SMF configures a DNS message handling rule to V-EASDF, indicating that when the FQDN contained in the DNS query meets the FQDN range configured by V-SMF, the common EAS deployed in the VPLMN is selected based on the existing technology. Alternatively, the common DNAI of the local DN accessing the VPLMN is selected through the Local DNS Server / Resolver or V-EASDF.

[0578] Step 43b: If step 42b is executed, the H-SMF selects the commonEAS deployed in the HPLMN based on the existing technology, or selects the common DNAI of the DN accessed to the HPLMN.

[0579] As another optional embodiment, AF provides common EAS IPaddress / common DNAI, EAS Correlation indication, Traffic Correlation ID and other information by interacting with the network elements of HPLMN, and 5GC determines whether the traffic of the application to be used by the UE supports routing to the local DN of the VPLMN, and determines whether to use the common EAS / common DNAI provided by AF or reselect the common EAS / common DNAI.

[0580] like Figure 5 As shown, the method includes:

[0581] Step 50: The roaming UE establishes a HR / HR-SBO session.

[0582] Step 51: Optionally, the H-SMF determines candidate DNAI(s) based on the UE location, the available DNAI list provided by the AF, the VPLMN Specific Offloading Information, the EASDeployment Information and other information, and sends the candidate DNAI to the AF.

[0583] Step 52: The AF determines the common EAS or common DNAI to be accessed for a group of UEs using a specific application. If the H-SMF sends the candidate DNAI(s) to the AF in step 51, the AF may determine the common EAS or common DNAI based on the candidate DNAI(s).

[0584] The AF sends the UE Identifier(s), Common EAS IP address, Common DNAI, EAS Correlation indication, Traffic Correlation ID, FQDN(s) and other information to the H-PCF through the H-NEF and H-UDR, requesting the determination of common EAS or common DNAI for the terminal. It should be noted that only one of the Common EAS IP address and Common DNAI is provided.

[0585] Step 53: Based on the AF request, the H-PCF generates a PCC rule including Common EAS IP address or Common DNAI, Traffic Correlation ID, EAS Correlation indication, and FQDN(s), and sends the PCC rule to the H-SMF.

[0586] Step 54: Based on the PCC rule, the H-SMF determines that the UE belongs to the UE group identified by the Traffic Correlation ID, and determines that this UE group needs to access the provided common EAS or Common DNAI.

[0587] Specifically, step 54 may include:

[0588] Step 54a. If the common EAS provided by AF is deployed in the VPLMN or the common DNAI is used to access the local DN of the VPLMN, and the H-SMF determines that the FQDN contained in the PCC or the Common EAS IP address is allowed to be routed to the local DN of the VPLMN (for example, the FQDN in the VPLMN Specific Offloading Information contains the FQDN in the PCC, and the IPrange contains the Common EAS IP address), then the H-SMF can send common EAS, EAS Correlation indication, Traffic Correlation ID, FQDN and other information to the V-SMF.

[0589] Step 54b. If the common EAS provided by the AF is deployed in the VPLMN or the common DNAI is used to access the local DN of the VPLMN, but the H-SMF determines that the FQDN contained in the PCC or the Common EAS IP address is not allowed to be routed to the local DN of the VPLMN (for example, the FQDN in the VPLMN Specific Offloading Information does not include the FQDN in the PCC rule, and the IP range does not include the Common EAS IP address), it is determined that the common EAS deployed in the HPLMN needs to be reselected and the common DNAI needs to be selected to access the DN of the HPLMN.

[0590] Step 54c: If the common EAS provided by the AF is deployed in the HPLMN or the common DNAI is used to access the local DN of the HPLMN, it is determined to select the common EAS deployed in the HPLMN or select the common DNAI to access the DN of the HPLMN.

[0591] Step 55a. If step 54a is executed, V-SMF also needs to configure the DNS messagehandling rule to V-EASDF, indicating that when the FQDN contained in the DNS query meets the FQDN range configured by V-SMF, it is necessary to send common EAS (that is, the common EAS received in step 52) to the UE, or select the common DNAI received in step 52.

[0592] Step 55b: If step 54b or step 54c is executed, the H-SMF selects the common EAS deployed in the HPLMN based on the existing technology, or selects the common DNAI of the DN accessing the HPLMN.

[0593] As another optional embodiment, AF provides common EAS / commonDNAI, EAS Correlation indication, Traffic Correlation ID and other information by interacting with the network elements of the VPLMN, and 5GC determines whether the traffic of the application to be used by the UE supports routing to the local DN of the VPLMN, and determines whether to use the common EAS / common DNAI provided by the AF or reselect the common EAS / common DNAI.

[0594] like Figure 6a As shown, the method includes:

[0595] Step 60: The roaming UE establishes a HR / HR-SBO session.

[0596] Step 61: Optionally, the V-SMF determines candidate DNAI(s) based on the UE location, the available DNAI list provided by the AF, and information such as VPLMN Specific Offloading Information and EASDeployment Information, and sends the candidate DNAI(s) to the AF.

[0597] Step 62: The AF determines the common EAS or common DNAI to be accessed for a group of UEs using a specific application. If the V-SMF sends the candidate DNAI(s) to the AF in step 61, the AF may determine the common EAS or common DNAI based on the candidate DNAI(s).

[0598] Step 62a: Optionally, the AF sends the UE Identifier(s), Common EAS IP address, Common DNAI, EAS Correlation indication, Traffic Correlation ID, FQDN(s) and other information to the V-SMF via the V-NEF and V-UDR. It should be noted that only one of the Common EAS IP address and Common DNAI is provided.

[0599] Step 62b, optionally, AF sends UE Identifier(s), Common EAS IPaddress, Common DNAI, EAS Correlation indication, Traffic CorrelationID, FQDN(s) and other information to V-PCF through V-NEF and V-UDR, and only provides one of Common EAS and Common DNAI. Based on AF's request, V-PCF generates PCC rules including Traffic Correlation ID, EAS Correlation indication, Common EAS IPaddress / Common DNAI, FQDN(s), and sends the PCC rules to V-SMF.

[0600] Step 63: V-SMF determines that the UE belongs to the UE group identified by the Traffic Correlation ID, and this UE group needs to access the common EAS / common DNAI.

[0601] Specifically, step 63 may include:

[0602] Step 63a: If the common EAS provided by the AF is deployed in the VPLMN or the common DNAI is used to access the local DN of the VPLMN, and the V-SMF determines that the FQDN or the Common EAS IP address received in step 62 is allowed to be routed to the local DN of the VPLMN, then it is determined that the common EAS deployed in the VPLMN can be selected or the common DNAI can be selected to access the local DN of the VPLMN.

[0603] Step 63b: If the common EAS provided by the AF is deployed in the VPLMN or the common DNAI is used to access the local DN of the VPLMN, but the V-SMF determines that the FQDN or Common EAS IP address received in step 62 is not allowed to be routed to the local DN of the VPLMN, it is determined that the common EAS deployed in the HPLMN needs to be reselected and the common DNAI is selected to access the DN of the HPLMN. The V-SMF sends EAS Correlation indication, Traffic Correlation ID, FQDN and other information to the H-SMF through Nsmf_PDUSession_Update request or Nsmf_PDUSession_StatusNotify request.

[0604] Step 63c: If the common EAS provided by the AF is deployed in the HPLMN or the common DNAI is used to access the local DN of the HPLMN, it is determined that the common EAS deployed in the HPLMN can be selected to select the common DNAI to access the DN of the HPLMN. The V-SMF sends EAS Correlation indication, Traffic Correlation ID, FQDN and other information to the H-SMF through Nsmf_PDUSession_Update request or Nsmf_PDUSession_StatusNotify request.

[0605] Step 64a. If step 63a is executed, V-SMF configures the DNS message handling rule to V-EASDF, indicating that when the FQDN contained in the DNS query meets the FQDN range configured by V-SMF, V-SMF also needs to provide commonEAS (i.e., common EAS received in step 62) to UE, or select the common DNAI received in step 62.

[0606] Step 64b: If step 63b or step 63c is executed, the H-SMF selects the common EAS deployed in the HPLMN based on the existing technology, or selects the common DNAI of the DN accessing the HPLMN.

[0607] In the above embodiment, for a roaming UE that establishes an HR / HR-SBO session, the 5GC determines whether the application traffic supports routing to the local DN of the VPLMN through the interaction between the AF and the network element of the HPLMN or the network element of the VPLMN, thereby selecting the common EAS deployed in the VPLMN or the common EAS deployed in the HPLMN for the roaming UE, or selecting a suitable common DNAI.

[0608] like Figure 6b As shown, the method includes:

[0609] Step b0: The roaming UE establishes a HR / HR-SBO session.

[0610] Step b11: V-SMF subscribes to the notification message of AF traffic influence request information from V-NEF.

[0611] Step b12: V-NEF subscribes to the notification message of AF traffic influence request information from V-UDR. NEF uses a notification endpoint to update the AF influence data associated with the Trafficcorrelation ID in the UDR, thereby subscribing the participating SMF related information for the members of the UE group.

[0612] Step b2: AF sends a request message, requesting to select common EAS or common DNAI for a group of UEs accessing a specific application.

[0613] The AF may use an External / Internal Group ID(s) or a list of UEs or any UE as Target UE Identifier(s) and additionally Spatial Validity Condition to identify a group of UEs associated with a common EAS or common DNAI. For example, the AF indicates a group of roaming UEs by providing an External Group ID.

[0614] The AF request may also include: EAS Correlation indication, Traffic Correlation ID, Common EAS or common DNAI (if provided by the AF), FQDN, and Spatial Validity Condition.

[0615] Step b3: The V-UDR notifies the V-NEF that has subscribed to the AF traffic influence request information. The notification message includes the information in step b2.

[0616] Step b4: The V-UDR notifies the V-PCF that has subscribed to the AF traffic influence request information. The notification message includes the information in step b1.

[0617] Step b5a, (if the member of the UE group is a non-roaming UE), the PCF generates a PCC rule including Traffic Correlation ID, EAS Correlation indication, Common EAS or common DNAI, FQDN(s), and NEF subscription, and sends it to the SMF.

[0618] Step b5b, (if the members of the UE group are roaming UEs) If the AF provides an External Group ID to identify a group of roaming UEs, the V-NEF determines the HPLMN to which the UE belongs and obtains the Internal Group ID from the UDM through the H-NEF.

[0619] If the V-NEF does not have the common EAS IP address or common DNAI associated with the requested Traffic correlation ID, the V-NEF uses the Traffic correlation ID to request the common EAS IP address or common DNAI from the H-NEF.

[0620] The V-NEF determines the UE affected by the AF request and provides the Traffic Correlation ID, EAS Correlation indication or indication of traffic correlation, Common EAS or common DNAI, FQDN(s), and NEF subscription information (e.g., notification endpoint) to the V-SMF that has subscribed to the AF traffic influence request information.

[0621] V-SMF can initiate the EAS rediscovery process based on the information notified by V-NEF.

[0622] Step b6a: (if the member of the UE group is a non-roaming UE) determine a common EAS IP address or a common DNAI based on an existing method, and provide the common EAS IP address to the UE.

[0623] Step b6b, (if the member of the UE group is a roaming UE) If the FQDN carried in the DNS query request sent by the UE matches the FQDN sent by the V-NEF, for example, the FQDN received from the V-NEF contains the FQDN carried in the DNS query request. And if the EAS Correlation indication or indication of traffic correlation is set, the SMF determines that the UE identified by the Traffic Correlation ID requires a UE group, and for this UE group, it is necessary to connect to a common EAS or select a common DNAI.

[0624] In the scenario where common EAS is selected, perform the following operations:

[0625] (1) If the V-SMF determines that the target FQDN in the DNS query request has been authorized by the H-SMF (i.e., access to the EAS deployed in the VPLMN is allowed), the following steps are performed:

[0626] (1.1) If no common EAS is received in the notification message sent by V-NEF, or V-SMF decides to trigger the EAS discovery process to select a new EAS for the UE group, V-SMF discovers common EAS based on the technology of discovering EAS through HR-SBO PDU session. In addition, the common EAS IP coordination process is performed to provide the new common EAS IP address to NEF (according to the notification endpoint provided by NEF in 5b).

[0627] (1.2) If V-SMF has an available common EAS IP address, there is no need to execute (1.1).

[0628] (2) If the V-SMF determines that the target FQDN in the DNS query request is not authorized by the H-SMF (i.e., access to the EAS deployed in the VPLMN is not allowed), the following steps are performed:

[0629] (2.1) If common EAS is not received from the notification information sent by V-NEF, or V-SMF decides to trigger the EAS discovery process to select a new EAS for the UE group, V-SMF can discover common EAS based on the technology of discovering EAS through HR-SBO PDU session.

[0630] And / or, V-SMF may also send one or more of EAS Correlation indication, Traffic Correlation ID, and FQDN to H-SMF via Nsmf_PDU session status notification request (Nsmf_PDUSession_StatusNotify request), and H-SMF discovers common EAS based on the technology of discovering EAS through HR-SBO PDU session.

[0631] And / or, the V-SMF may request the NEF to determine the common EAS IP address.

[0632] In addition, V-SMF can also perform the common EAS IP coordination process, and SMF provides the new common EAS IP address to NEF (V-NEF or H-NEF).

[0633] (2.2) If V-SMF has an available common EAS IP address, there is no need to execute (2.1).

[0634] For the scenario where common DNAI is selected, do the following:

[0635] If the V-SMF does not receive the common DNAI from the notification information sent by the V-NEF, the V-SMF requests the NEF to determine the common DNAI.

[0636] (If the members of the UE group are roaming UEs) Perform the following steps for the scenario where common EAS is selected:

[0637] Step b7: V-SMF can determine DNAI based on common EAS.

[0638] Step b8, V-SMF sends a DNS message handling rule containing the common EAS IP address and setting the Forwarding Action to "Respond directly to the DNS request" to V-EASDF, to instruct V-EASDF to directly reply the common EAS IP address to the UE via a DNS response.

[0639] Step b9: V-EASDF replies to UE via DNS response including common EAS IP address.

[0640] (If the members of the UE group are roaming UEs) For the scenario where common DNAI is selected, perform the following steps:

[0641] Step b10: When the common DNAI is determined, V-SMF provides V-EASDF with information for constructing an EDNS Client Subnet option, where the EDNS Client Subnet option indicates a location that is topologically close to the common DNAI. Alternatively, V-SMF provides V-EASDF with a local DNS server associated with the common DNAI.

[0642] In an embodiment of the present application, the SMF determines whether the traffic of the application to be used by the terminal supports routing to the local DN of the VPLMN, thereby selecting a public EAS or public DNAI deployed in the VPLMN for the terminal, or selecting a public EAS or public DNAI deployed in the HPLMN, thereby enabling selection of a suitable public EAS or public DNAI for the terminal.

[0643] The embodiment of the present application also provides a method for discovering an edge application server, which is executed by the NEF and includes:

[0644] Receiving a first subscription message sent by the SMF of the VPLMN, where the first subscription message is used to subscribe to a notification message of AF traffic impact request information;

[0645] Sending a first notification message to the SMF of the VPLMN;

[0646] The first notification message includes at least one of the following information:

[0647] Traffic correlation identification;

[0648] EAS relevance indication;

[0649] Traffic correlation indication;

[0650] The IP address of the public EAS;

[0651] Public DNAI;

[0652] FQDN;

[0653] Information about NEF.

[0654] In this embodiment, the NEF may be a V-NEF or an H-NEF. The V-SMF may subscribe to the notification message of the AF traffic response request message to the V-NEF through a first subscription message. The AF sends a request message requesting the selection of common EAS or common DNAI for a group of UEs accessing a specific application, and the V-UDR notifies the V-NEF that has subscribed to the AF traffic influencerequest information. The V-NEF determines the UE affected by the AF request, and provides the first notification message to the V-SMF that has subscribed to the notification message of the AF traffic response request message.

[0655] Optionally, the method further includes:

[0656] Sending a second subscription message to the UDR of the VPLMN, where the second subscription message is used to subscribe to a notification message of the AF traffic impact request information;

[0657] receiving a second notification message sent by the UDR of the VPLMN;

[0658] The sending a first notification message to the SMF of the VPLMN includes:

[0659] When it is determined according to the second notification message that the terminal affected by the AF request is a roaming terminal, sending the first notification message to the SMF of the VPLMN;

[0660] The second notification message includes at least one of the following:

[0661] Traffic correlation identification;

[0662] EAS relevance indication;

[0663] Traffic correlation indication;

[0664] The IP address of the public EAS;

[0665] Public DNAI;

[0666] FQDN;

[0667] Space validity conditions.

[0668] In this embodiment, V-SMF can subscribe to the notification message of AF traffic response request message from V-NEF; V-NEF can subscribe to the notification message of AF traffic response request message from V-UDR. AF sends a request message to request the selection of common EAS or common DNAI for a group of UEs accessing a specific application, and V-UDR notifies V-NEF that has subscribed to the notification message of AF traffic response request message through the second notification message. V-NEF determines that the UE affected by the AF request is a roaming UE, and provides the first notification message to V-SMF that has subscribed to the notification message of AF traffic response request message.

[0669] Optionally, the method further includes:

[0670] If the NEF of the VPLMN does not have the IP address or public DNAI of the public EAS associated with the traffic correlation identifier, a fourth request message is sent to the NEF of the HPLMN, where the fourth request message is used to request the IP address or public DNAI of the public EAS.

[0671] In this embodiment, if the V-NEF itself does not obtain the public EAS IP address or public DNAI, it can request the public EAS or public DNAI from the H-NEF. The V-NEF can use the Traffic correlation ID to request the common EAS IP address or common DNAI from the H-NEF.

[0672] Optionally, the method further includes:

[0673] Receiving a second request message sent by the SMF of the VPLMN;

[0674] A public EAS is determined according to the second request message.

[0675] In this embodiment, if the notification message sent by the V-NEF does not include the IP address of the public EAS, or the V-NEF determines to select a new EAS for the terminal, a second request message can be sent to the V-NEF and / or H-NEF, and the V-NEF and / or H-NEF determines the public EAS based on the second request message.

[0676] Optionally, the method further includes:

[0677] receiving a third request message sent by the SMF of the VPLMN;

[0678] A public DNAI is determined according to the third request message.

[0679] In this embodiment, if the notification message sent by the V-NEF to the V-SMF does not include the public DNAI, the V-SMF may send a third request message to the V-NEF, and the V-NEF determines the public DNAI according to the third request message.

[0680] Optionally, the method further includes:

[0681] Receive the IP address of the public EAS sent by the SMF of the VPLMN, where the public EAS is discovered by the SMF of the VPLMN.

[0682] In this embodiment, after the V-SMF determines the IP address of the public EAS, it can be sent to the V-NEF.

[0683] In an embodiment of the present application, the SMF may subscribe to the notification message of the AF traffic impact request information from the NEF. After the AF requests or sends a message to select a common EAS or common DNAI for the terminal, the UDR may send a notification message to the NEF that has subscribed to the notification message of the AF traffic impact request information. The NEF may send a notification message to the SMF that has subscribed to the notification message of the AF traffic impact request information. The notification message includes one or more of the traffic correlation identifier, EAS correlation indication, traffic correlation indication, IP address of the public EAS (if any), public DNAI (if any), FQDN, and NEF information. This enables the SMF to select a suitable public EAS or public DNAI for the terminal.

[0684] like Figure 7 As shown, the embodiment of the present application also provides a method for discovering an edge application server, which is executed by AF, and the method includes:

[0685] Step 701: Send a first request message to a target network element of a VPLMN;

[0686] The first request message includes at least one of the following information:

[0687] Terminal identification;

[0688] EAS relevance indication;

[0689] Traffic correlation identification;

[0690] Traffic correlation indication;

[0691] Application information;

[0692] The IP address or the candidate public DNAI of the candidate public EAS selected by the AF for the terminal.

[0693] Optionally, the application information includes at least one of the following:

[0694] At least one FQDN;

[0695] At least one EAS IP address.

[0696] In this embodiment, the target network element of the VPLMN may be a NEF of the VPLMN, a UDR of the VPLMN, a SMF of the VPLMN, or the like.

[0697] If the AF requests to select a common EAS or a common DNAI for a group of UEs using a specific application, a first request message may be sent to the target network element of the VPLMN. The first request message may include one or more of the following information: UE Identifier, EAS Correlation indication, Traffic Correlation ID, indication of traffic correlation, FQDN(s), etc.

[0698] Optionally, before sending the first request message to the target network element of the VPLMN, the method further includes: receiving a candidate DNAI sent by the SMF; and selecting a candidate public EAS or a candidate public DNAI for the terminal according to the candidate DNAI.

[0699] In this embodiment, the H-SMF or V-SMF can determine the candidate DNAI based on the UE location information, the available DNAI list provided by the AF, the VPLMN Specific Offloading Information, the EAS Deployment Information and other information, and send the determined candidate DNAI to the AF. The AF can select the candidate public EAS or candidate public DNAI for the terminal based on the candidate DNAI. And the UE Identifier, Common EAS IP address, Common DNAI, EASCorrelation indication, Traffic Correlation ID, FQDN and other information can be sent to the PCF or SMF. It should be noted that only one of the Common EAS IP address and Common DNAI is provided.

[0700] As an optional embodiment, the sending the first request message to the target network element of the VPLMN includes at least one of the following:

[0701] Sending the first request message to the SMF of the VPLMN through the network opening function NEF and / or UDR of the VPLMN;

[0702] The first request message is sent to the PCF of the VPLMN through the NEF and / or UDR of the VPLMN, so that the PCF of the VPLMN generates a PCC rule according to the first request message and sends the PCC rule to the SMF of the VPLMN.

[0703] In this embodiment, the AF may send the first request message to the V-NEF and / or V-UDR, and the V-NEF and / or V-UDR may send the first request message to the V-SMF. The V-NEF and / or V-UDR may also send the first request message to the V-PCF, and the V-PCF generates a PCC rule based on the information in the first request message, and sends the PCC rule to the V-SMF, so that the V-SMF determines whether the traffic of the application supports routing to the local DN of the VPLMN according to the first request message or the PCC rule, thereby selecting a public EAS or a public DNAI for the terminal.

[0704] In an embodiment of the present application, AF sends a first request message to a target network element of the VPLMN, so that the target network element sends the first request message to the SMF, or sends the first request message to the PCF, and the PCF generates a PCC rule and sends it to the SMF. The SMF determines whether the traffic of the application to be used by the terminal supports routing to the local DN of the VPLMN, thereby selecting a public EAS or public DNAI deployed in the VPLMN for the terminal, or selecting a public EAS or public DNAI deployed in the HPLMN, thereby enabling selection of a suitable public EAS or public DNAI for the terminal.

[0705] like Figure 8 As shown, the embodiment of the present application also provides a method for discovering an edge application server, which is executed by the PCF of the VPLMN, and the method includes:

[0706] Step 801: receiving a first request message;

[0707] Step 802: Generate a PCC rule according to the first request message;

[0708] Step 803: Send the PCC rule to the SMF of the VPLMN;

[0709] The first request message includes at least one of the following information:

[0710] Terminal identification;

[0711] EAS relevance indication;

[0712] Traffic correlation identification;

[0713] Traffic correlation indication;

[0714] Application information;

[0715] The IP address or the candidate public DNAI of the candidate public EAS selected by the AF for the terminal.

[0716] The PCC rule includes at least one of the following information:

[0717] Traffic correlation identification;

[0718] EAS relevance indication;

[0719] Application information;

[0720] The IP address or the candidate public DNAI of the candidate public EAS selected by the AF for the terminal.

[0721] Optionally, the receiving a first request message includes: receiving a first request message sent by an NEF and / or UDR of the VPLMN.

[0722] Optionally, the application information includes at least one of the following:

[0723] At least one FQDN;

[0724] At least one EAS IP address.

[0725] In this embodiment, the AF can send a first request message to the V-PCF through the V-NEF and / or V-UDR. The V-PCF generates a PCC rule based on the information in the first request message and sends the PCC rule to the V-SMF, so that the V-SMF determines whether the traffic of the application supports routing to the local DN of the VPLMN based on the first request message or the PCC rule, thereby selecting a public EAS or a public DNAI for the terminal.

[0726] The above embodiment introduces the method for discovering the edge application server of the present application. The following embodiment will further illustrate the corresponding device in conjunction with the accompanying drawings.

[0727] Specifically, Fig. 9 As shown, the embodiment of the present application provides a discovery device 900 for an edge application server, which is applied to SMF and includes:

[0728] A first determining unit 910 is used to determine whether the traffic of the application supports routing to the local DN of the VPLMN;

[0729] The second determining unit 920 is configured to determine, if the traffic of the application supports routing to the local DN of the VPLMN, whether to select a public edge application server EAS deployed in the VPLMN or a public data network access identifier DNAI for accessing the VPLMN for the terminal;

[0730] If the traffic of the application does not support routing to the local DN of the VPLMN, it is determined that a public EAS deployed in the home public land mobile network HPLMN or a public DNAI for accessing the HPLMN is selected for the terminal.

[0731] Optionally, the first determining unit is specifically configured to:

[0732] Determining, according to the received first information, whether the traffic of the application supports routing to the local DN of the VPLMN;

[0733] The first information is: a policy and charging control PCC rule sent by a policy control function PCF or a first request message sent by an application function AF; or, the first information is: a DNS query request sent by a terminal.

[0734] Optionally, the PCC rule includes at least one of the following information:

[0735] Traffic correlation identification;

[0736] EAS relevance indication;

[0737] Application information;

[0738] The Internet Protocol IP address or the candidate public DNAI of the candidate public EAS selected by the AF for the terminal.

[0739] Optionally, the first request message includes at least one of the following information:

[0740] Terminal identification;

[0741] EAS relevance indication;

[0742] Traffic correlation identification;

[0743] Traffic correlation indication;

[0744] Application information;

[0745] The IP address or the candidate public DNAI of the candidate public EAS selected by the AF for the terminal.

[0746] Optionally, the first determining unit is specifically configured to perform at least one of the following:

[0747] In the case where the first information includes application information, if the application information included in the first information allows being routed to the local DN of the VPLMN, it is determined that traffic of the application supports being routed to the local DN of the VPLMN; if the application information included in the first information does not allow being routed to the local DN of the VPLMN, it is determined that traffic of the application does not support being routed to the local DN of the VPLMN;

[0748] or,

[0749] In the case that the first information includes application information and the IP address of the candidate public EAS or the candidate public DNAI selected by the AF for the terminal, if the candidate public EAS is deployed in the VPLMN or the candidate public DNAI is used to access the VPLMN, and the application information and the candidate public EAS or the candidate public DNAI contained in the first information are allowed to be routed to the local DN of the VPLMN, it is determined that the traffic of the application supports routing to the local DN of the VPLMN; if the candidate public EAS is deployed in the VPLMN or the candidate public DNAI is used to access the VPLMN, and the application information and the candidate public EAS or the candidate public DNAI contained in the first information are not allowed to be routed to the local DN of the VPLMN, it is determined that the traffic of the application does not support routing to the local DN of the VPLMN.

[0750] Optionally, the application information included in the first information is allowed to be routed to the local DN of the VPLMN, including:

[0751] The application information in the VPLMN uninstall information includes the application information in the first information;

[0752] The candidate public EAS or candidate public DNAI allows being routed to the local DN of the VPLMN, including:

[0753] The IP range in the VPLMN offload information includes the IP address of the candidate public EAS.

[0754] Optionally, the device further includes: a third determining unit; the third determining unit is specifically configured to:

[0755] In the case where the first information includes the IP address of the candidate public EAS or the candidate public DNAI selected by the AF for the terminal, if it is determined that the traffic of the application supports routing to the local DN of the VPLMN, then determining the candidate public EAS or the candidate public DNAI as the public EAS or public DNAI of the terminal;

[0756] When the first information includes the IP address of the candidate public EAS or the candidate public DNAI selected by the AF for the terminal, if it is determined that the traffic of the application does not support routing to the local DN of the VPLMN, a public EAS deployed in the HPLMN or a public DNAI for accessing the HPLMN is reselected for the terminal.

[0757] Optionally, the first determining unit is further configured to:

[0758] In the case where the first information includes the IP address or candidate public DNAI of the candidate public EAS selected by the AF for the terminal, if the candidate public EAS is deployed in the HPLMN or the candidate public DNAI is used to access the HPLMN, it is determined that the traffic of the application does not support routing to the local DN of the VPLMN.

[0759] Optionally, the device further includes: a third sending unit; the third sending unit is specifically configured to:

[0760] If the SMF is the SMF of the HPLMN, and the traffic of the application supports routing to the local DN of the VPLMN, sending the second information to the SMF of the VPLMN;

[0761] The second information includes at least one of the following:

[0762] EAS relevance indication;

[0763] Traffic correlation identification;

[0764] Application information;

[0765] The IP address or the candidate public DNAI of the candidate public EAS selected by the AF for the terminal.

[0766] Optionally, the device further includes: a fourth sending unit; the fourth sending unit is specifically configured to:

[0767] If the SMF is the SMF of the VPLMN, and the traffic of the application does not support routing to the local DN of the VPLMN, sending third information to the SMF of the HPLMN;

[0768] The third information includes at least one of the following:

[0769] EAS relevance indication;

[0770] Traffic correlation identification;

[0771] Application information.

[0772] Optionally, the device further includes: a fifth sending unit; the fifth sending unit is specifically configured to:

[0773] If the SMF is the SMF of the VPLMN, and it is determined that a public EAS deployed in the VPLMN or a public DNAI for accessing the VPLMN is selected for the terminal, a domain name system DNS message processing rule is sent to the edge application server discovery function EASDF of the VPLMN;

[0774] The DNS message processing rule is used to indicate: when the application information contained in the DNS query meets the application information range configured by the SMF of the VPLMN, select a public EAS deployed in the VPLMN or a public DNAI for accessing the VPLMN for the terminal.

[0775] Optionally, the device further comprises:

[0776] a fourth determining unit, configured to determine a candidate DNAI based on fourth information;

[0777] A sixth sending unit, configured to send the candidate DNAI to the AF;

[0778] The fourth information includes at least one of the following:

[0779] Terminal location information;

[0780] Available DNAI information;

[0781] VPLMN uninstall information;

[0782] EAS deployment information.

[0783] Optionally, the application information includes at least one of the following:

[0784] At least one fully qualified domain name (FQDN);

[0785] At least one EAS IP address.

[0786] Optionally, the first determining unit is specifically configured to:

[0787] If it is determined that the FQDN carried in the DNS query request sent by the terminal is authorized by the SMF of the HPLMN, it is determined that the traffic of the application supports routing to the local DN of the VPLMN;

[0788] or,

[0789] If it is determined that the FQDN carried in the DNS query request sent by the terminal has not been authorized by the SMF of the HPLMN, it is determined that the traffic of the application does not support routing to the local DN of the VPLMN.

[0790] Optionally, the second determining unit is specifically configured to:

[0791] If the FQDN carried in the DNS query request sent by the terminal matches the FQDN sent by the NEF of the VPLMN and is configured with an EAS correlation indication or a traffic correlation indication, it is determined that the terminal selects a public EAS deployed in the VPLMN or a public DNAI for accessing the VPLMN.

[0792] Optionally, the device further comprises:

[0793] A first discovery unit, configured to discover a public EAS deployed in the VPLMN if the notification message sent by the NEF of the VPLMN does not include the IP address of the public EAS, or the SMF of the VPLMN determines to select a new EAS for the terminal;

[0794] The fifth determining unit is configured to determine, if the SMF of the VPLMN has an IP address of a public EAS, the IP address of the public EAS as the public EAS deployed in the VPLMN selected for the terminal.

[0795] Optionally, the device further comprises:

[0796] an eighth sending unit, configured to, if the notification message sent by the NEF of the VPLMN does not include the IP address of the public EAS, or the SMF of the VPLMN determines to select a new EAS for the terminal, perform at least one of the following:

[0797] Discover the public EAS deployed in the HPLMN;

[0798] Sending fifth information to the SMF of the HPLMN, the fifth information being used to request the SMF of the HPLMN to discover a public EAS; the fifth information comprising at least one of an EAS correlation indication, a traffic correlation identifier, and an FQDN;

[0799] Sending a second request message to the NEF of the VPLMN and / or the NEF of the HPLMN, where the second request message is used to request the NEF to determine a common EAS;

[0800] The sixth determining unit is configured to determine, if the SMF of the VPLMN has an IP address of a public EAS, the IP address of the public EAS as the public EAS deployed in the HPLMN selected for the terminal.

[0801] Optionally, the device further comprises:

[0802] The ninth sending unit is configured to send the IP address of the public EAS to the NEF of the VPLMN and / or the NEF of the HPLMN.

[0803] Optionally, the device further comprises:

[0804] The tenth sending unit is configured to send a third request message to the NEF of the VPLMN if the notification message sent by the NEF of the VPLMN does not include the public DNAI, wherein the third request message is used to request the NEF of the VPLMN to determine the public DNAI.

[0805] Optionally, the device further comprises:

[0806] A seventh determining unit is configured to determine the DNAI based on the public EAS.

[0807] Optionally, the device further comprises:

[0808] an eleventh sending unit, configured to send a DNS message processing rule to the EASDF of the VPLMN, wherein the DNS message processing rule is used to instruct the EASDF of the VPLMN to send the IP address of the public EAS to the terminal;

[0809] The DNS message processing rules include: a public EAS IP address and forwarding operation instruction information set to directly respond to the DNS request.

[0810] Optionally, the device further comprises:

[0811] The twelfth sending unit is used to send sixth information to the EASDF of the VPLMN; the sixth information includes information for constructing an EDNS client subnet option; or the sixth information includes information of a local DNS server related to the public DNAI.

[0812] Optionally, the device further comprises:

[0813] A thirteenth sending unit, configured to send a first subscription message to the NEF of the VPLMN and / or the NEF of the HPLMN, where the first subscription message is used to subscribe to a notification message of the AF traffic impact request information;

[0814] a fourth receiving unit, configured to receive a first notification message sent by the NEF of the VPLMN and / or the NEF of the HPLMN;

[0815] The first notification message includes at least one of the following information:

[0816] Traffic correlation identification;

[0817] EAS relevance indication;

[0818] Traffic correlation indication;

[0819] The IP address of the public EAS;

[0820] Public DNAI;

[0821] FQDN;

[0822] Information about NEF.

[0823] It should be noted here that the above-mentioned device provided in the embodiment of the present application can implement all the method steps implemented by the above-mentioned method embodiment applied to SMF, and can achieve the same technical effect. The parts and beneficial effects of this embodiment that are the same as the method embodiment will not be described in detail here.

[0824] Specifically, an embodiment of the present application provides a discovery device for an edge application server, which is applied to NEF, including:

[0825] A third receiving unit is used to receive a first subscription message sent by the SMF of the VPLMN, where the first subscription message is used to subscribe to a notification message of the AF traffic impact request information;

[0826] A seventh sending unit, configured to send a first notification message to the SMF of the VPLMN;

[0827] The first notification message includes at least one of the following information:

[0828] Traffic correlation identification;

[0829] EAS relevance indication;

[0830] Traffic correlation indication;

[0831] The IP address of the public EAS;

[0832] Public DNAI;

[0833] FQDN;

[0834] Information about NEF.

[0835] Optionally, the device further comprises:

[0836] A fourteenth sending unit, configured to send a second subscription message to the UDR of the VPLMN, where the second subscription message is used to subscribe to a notification message of the AF traffic impact request information;

[0837] a fifth receiving unit, configured to receive a second notification message sent by the UDR of the VPLMN;

[0838] The seventh sending unit is specifically used for:

[0839] When it is determined according to the second notification message that the terminal affected by the AF request is a roaming terminal, sending the first notification message to the SMF of the VPLMN;

[0840] The second notification message includes at least one of the following:

[0841] Traffic correlation identification;

[0842] EAS relevance indication;

[0843] Traffic correlation indication;

[0844] The IP address of the public EAS;

[0845] Public DNAI;

[0846] FQDN;

[0847] Space validity conditions.

[0848] Optionally, the device further comprises:

[0849] The fifteenth sending unit is configured to send a fourth request message to the NEF of the HPLMN if the NEF of the VPLMN does not have the IP address or public DNAI of the public EAS associated with the traffic correlation identifier, wherein the fourth request message is used to request the IP address or public DNAI of the public EAS.

[0850] Optionally, the device further comprises:

[0851] A sixth receiving unit, configured to receive a second request message sent by the SMF of the VPLMN;

[0852] An eighth determining unit is configured to determine a public EAS according to the second request message.

[0853] Optionally, the device further comprises:

[0854] A seventh receiving unit, configured to receive a third request message sent by the SMF of the VPLMN;

[0855] A ninth determining unit is configured to determine a public DNAI according to the third request message.

[0856] Optionally, the device further comprises:

[0857] The eighth receiving unit is used to receive the IP address of the public EAS sent by the SMF of the VPLMN, where the public EAS is discovered by the SMF of the VPLMN.

[0858] It should be noted here that the above-mentioned device provided in the embodiment of the present application can implement all the method steps implemented in the above-mentioned method embodiment applied to NEF, and can achieve the same technical effect. The parts and beneficial effects of this embodiment that are the same as those of the method embodiment will not be described in detail here.

[0859] Specifically, Fig.10As shown, the embodiment of the present application provides a discovery device 1000 for an edge application server, which is applied to AF, including:

[0860] The first sending unit 1010 is configured to send a first request message to a target network element of the VPLMN;

[0861] The first request message includes at least one of the following information:

[0862] Terminal identification;

[0863] EAS relevance indication;

[0864] Traffic correlation identification;

[0865] Traffic correlation indication;

[0866] Application information;

[0867] The IP address or the candidate public DNAI of the candidate public EAS selected by the AF for the terminal.

[0868] Optionally, the device further comprises:

[0869] A second receiving unit, configured to receive a candidate DNAI sent by the SMF;

[0870] The selection unit is used to select a candidate public EAS or a candidate public DNAI for the terminal according to the candidate DNAI.

[0871] Optionally, the first sending unit is specifically configured to perform at least one of the following:

[0872] Sending the first request message to the SMF of the VPLMN through the network opening function NEF and / or UDR of the VPLMN;

[0873] The first request message is sent to the PCF of the VPLMN through the NEF and / or UDR of the VPLMN, so that the PCF of the VPLMN generates a PCC rule according to the first request message and sends the PCC rule to the SMF of the VPLMN.

[0874] Optionally, the application information includes at least one of the following:

[0875] At least one FQDN;

[0876] At least one EAS IP address.

[0877] It should be noted here that the above-mentioned device provided in the embodiment of the present application can implement all the method steps implemented in the above-mentioned method embodiment applied to AF, and can achieve the same technical effect. The parts and beneficial effects of this embodiment that are the same as the method embodiment will not be described in detail here.

[0878] Specifically, Fig.11 As shown, the embodiment of the present application provides a discovery device 1100 for an edge application server, which is applied to a PCF of a VPLMN, including:

[0879] The first receiving unit 1110 is configured to receive a first request message;

[0880] A generating unit 1120, configured to generate a PCC rule according to the first request message;

[0881] The second sending unit 1130 is configured to send the PCC rule to the SMF of the VPLMN;

[0882] The first request message includes at least one of the following information:

[0883] Terminal identification;

[0884] EAS relevance indication;

[0885] Traffic correlation identification;

[0886] Traffic correlation indication;

[0887] Application information;

[0888] The IP address or the candidate public DNAI of the candidate public EAS selected by the AF for the terminal.

[0889] The PCC rule includes at least one of the following information:

[0890] Traffic correlation identification;

[0891] EAS relevance indication;

[0892] Application information;

[0893] The IP address or the candidate public DNAI of the candidate public EAS selected by the AF for the terminal.

[0894] Optionally, the first receiving unit is specifically configured to:

[0895] Receive a first request message sent by the NEF and / or UDR of the VPLMN.

[0896] Optionally, the application information includes at least one of the following:

[0897] At least one FQDN;

[0898] At least one EAS IP address.

[0899] It should be noted here that the above-mentioned device provided in the embodiment of the present application can implement all the method steps implemented in the above-mentioned method embodiment applied to PCF, and can achieve the same technical effect. The parts and beneficial effects of this embodiment that are the same as the method embodiment will not be described in detail here.

[0900] It should be noted that the division of units in the embodiments of the present application is schematic and is only a logical function division. There may be other division methods in actual implementation. In addition, each functional unit in each embodiment of the present application may be integrated into a processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0901] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a processor-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, server, or network device, etc.) or a processor (processor) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (Read-Only Memory, ROM), random access memory (Random Access Memory, RAM), disk or optical disk and other media that can store program codes.

[0902] like Fig.12 As shown, an embodiment of the present application further provides a network device, which may be an SMF, and includes: a memory 1220, a transceiver 1200, and a processor 1210; wherein the memory 1220 is used to store a computer program; the transceiver 1200 is used to receive and send data under the control of the processor 1210; the processor 1210 is used to read the computer program in the memory and perform the following operations:

[0903] Determine whether the traffic of the application supports routing to the local data network DN of the visited public land mobile network VPLMN;

[0904] If the traffic of the application supports routing to the local DN of the VPLMN, it is determined that a public edge application server EAS deployed in the VPLMN or a public data network access identifier DNAI for accessing the VPLMN is selected for the terminal;

[0905] If the traffic of the application does not support routing to the local DN of the VPLMN, it is determined that a public EAS deployed in the home public land mobile network HPLMN or a public DNAI for accessing the HPLMN is selected for the terminal.

[0906] Optionally, the processor is configured to read the computer program in the memory and perform the following operations:

[0907] Determining, according to the received first information, whether the traffic of the application supports routing to the local DN of the VPLMN;

[0908] The first information is: a policy and charging control PCC rule sent by a policy control function PCF or a first request message sent by an application function AF; or, the first information is: a DNS query request sent by a terminal.

[0909] Optionally, the PCC rule includes at least one of the following information:

[0910] Traffic correlation identification;

[0911] EAS relevance indication;

[0912] Application information;

[0913] The Internet Protocol IP address or the candidate public DNAI of the candidate public EAS selected by the AF for the terminal.

[0914] Optionally, the first request message includes at least one of the following information:

[0915] Terminal identification;

[0916] EAS relevance indication;

[0917] Traffic correlation identification;

[0918] Traffic correlation indication;

[0919] Application information;

[0920] The IP address or the candidate public DNAI of the candidate public EAS selected by the AF for the terminal.

[0921] Optionally, the processor is configured to read the computer program in the memory and perform at least one of the following operations:

[0922] In the case where the first information includes application information, if the application information included in the first information allows being routed to the local DN of the VPLMN, it is determined that traffic of the application supports being routed to the local DN of the VPLMN; if the application information included in the first information does not allow being routed to the local DN of the VPLMN, it is determined that traffic of the application does not support being routed to the local DN of the VPLMN;

[0923] or,

[0924] In the case that the first information includes application information and the IP address of the candidate public EAS or the candidate public DNAI selected by the AF for the terminal, if the candidate public EAS is deployed in the VPLMN or the candidate public DNAI is used to access the VPLMN, and the application information and the candidate public EAS or the candidate public DNAI contained in the first information are allowed to be routed to the local DN of the VPLMN, it is determined that the traffic of the application supports routing to the local DN of the VPLMN; if the candidate public EAS is deployed in the VPLMN or the candidate public DNAI is used to access the VPLMN, and the application information and the candidate public EAS or the candidate public DNAI contained in the first information are not allowed to be routed to the local DN of the VPLMN, it is determined that the traffic of the application does not support routing to the local DN of the VPLMN.

[0925] Optionally, the application information included in the first information is allowed to be routed to the local DN of the VPLMN, including:

[0926] The application information in the VPLMN uninstall information includes the application information in the first information;

[0927] The candidate public EAS or candidate public DNAI allows being routed to the local DN of the VPLMN, including:

[0928] The IP range in the VPLMN offload information includes the IP address of the candidate public EAS.

[0929] Optionally, the processor is configured to read the computer program in the memory and perform the following operations:

[0930] In the case where the first information includes the IP address of the candidate public EAS or the candidate public DNAI selected by the AF for the terminal, if it is determined that the traffic of the application supports routing to the local DN of the VPLMN, then determining the candidate public EAS or the candidate public DNAI as the public EAS or public DNAI of the terminal;

[0931] When the first information includes the IP address of the candidate public EAS or the candidate public DNAI selected by the AF for the terminal, if it is determined that the traffic of the application does not support routing to the local DN of the VPLMN, a public EAS deployed in the HPLMN or a public DNAI for accessing the HPLMN is reselected for the terminal.

[0932] Optionally, the processor is configured to read the computer program in the memory and perform the following operations:

[0933] In the case where the first information includes the IP address or candidate public DNAI of the candidate public EAS selected by the AF for the terminal, if the candidate public EAS is deployed in the HPLMN or the candidate public DNAI is used to access the HPLMN, it is determined that the traffic of the application does not support routing to the local DN of the VPLMN.

[0934] Optionally, the processor is configured to read the computer program in the memory and perform the following operations:

[0935] If the SMF is the SMF of the HPLMN, and the traffic of the application supports routing to the local DN of the VPLMN, sending the second information to the SMF of the VPLMN;

[0936] The second information includes at least one of the following:

[0937] EAS relevance indication;

[0938] Traffic correlation identification;

[0939] Application information;

[0940] The IP address or the candidate public DNAI of the candidate public EAS selected by the AF for the terminal.

[0941] Optionally, the processor is configured to read the computer program in the memory and perform the following operations:

[0942] If the SMF is the SMF of the VPLMN, and the traffic of the application does not support routing to the local DN of the VPLMN, sending third information to the SMF of the HPLMN;

[0943] The third information includes at least one of the following:

[0944] EAS relevance indication;

[0945] Traffic correlation identification;

[0946] Application information.

[0947] Optionally, the processor is configured to read the computer program in the memory and perform the following operations:

[0948] If the SMF is the SMF of the VPLMN, and it is determined that a public EAS deployed in the VPLMN or a public DNAI for accessing the VPLMN is selected for the terminal, a DNS message processing rule is sent to the EASDF of the VPLMN;

[0949] The DNS message processing rule is used to indicate: when the application information contained in the DNS query meets the application information range configured by the SMF of the VPLMN, select a public EAS deployed in the VPLMN or a public DNAI for accessing the VPLMN for the terminal.

[0950] Optionally, the processor is configured to read the computer program in the memory and perform the following operations:

[0951] determining a candidate DNAI based on the fourth information;

[0952] Sending the candidate DNAI to the AF;

[0953] The fourth information includes at least one of the following:

[0954] Terminal location information;

[0955] Available DNAI information;

[0956] VPLMN uninstall information

[0957] EAS deployment information.

[0958] Optionally, the application information includes at least one of the following:

[0959] At least one fully qualified domain name (FQDN);

[0960] At least one EAS IP address.

[0961] Optionally, the processor is configured to read the computer program in the memory and perform the following operations:

[0962] If it is determined that the FQDN carried in the DNS query request sent by the terminal is authorized by the SMF of the HPLMN, it is determined that the traffic of the application supports routing to the local DN of the VPLMN;

[0963] or,

[0964] If it is determined that the FQDN carried in the DNS query request sent by the terminal has not been authorized by the SMF of the HPLMN, it is determined that the traffic of the application does not support routing to the local DN of the VPLMN.

[0965] Optionally, the processor is configured to read the computer program in the memory and perform the following operations:

[0966] If the FQDN carried in the DNS query request sent by the terminal matches the FQDN sent by the NEF of the VPLMN and is configured with an EAS correlation indication or a traffic correlation indication, it is determined that the terminal selects a public EAS deployed in the VPLMN or a public DNAI for accessing the VPLMN.

[0967] Optionally, the processor is configured to read the computer program in the memory and perform the following operations:

[0968] If the notification message sent by the NEF of the VPLMN does not include the IP address of the public EAS, or the SMF of the VPLMN determines to select a new EAS for the terminal, the public EAS deployed in the VPLMN is discovered;

[0969] If the SMF of the VPLMN has an IP address of a public EAS, the IP address of the public EAS is determined as the public EAS deployed in the VPLMN selected for the terminal.

[0970] Optionally, the processor is configured to read the computer program in the memory and perform the following operations:

[0971] If the notification message sent by the NEF of the VPLMN does not include the IP address of the public EAS, or the SMF of the VPLMN determines to select a new EAS for the terminal, at least one of the following is performed:

[0972] Discover the public EAS deployed in the HPLMN;

[0973] Sending fifth information to the SMF of the HPLMN, the fifth information being used to request the SMF of the HPLMN to discover a public EAS; the fifth information comprising at least one of an EAS correlation indication, a traffic correlation identifier, and an FQDN;

[0974] Sending a second request message to the NEF of the VPLMN and / or the NEF of the HPLMN, where the second request message is used to request the NEF to determine a common EAS;

[0975] If the SMF of the VPLMN has an IP address of a public EAS, the IP address of the public EAS is determined as the public EAS deployed in the HPLMN selected for the terminal.

[0976] Optionally, the processor is configured to read the computer program in the memory and perform the following operations:

[0977] The IP address of the public EAS is sent to the NEF of the VPLMN and / or the NEF of the HPLMN.

[0978] Optionally, the processor is configured to read the computer program in the memory and perform the following operations:

[0979] If the notification message sent by the NEF of the VPLMN does not include the public DNAI, a third request message is sent to the NEF of the VPLMN, where the third request message is used to request the NEF of the VPLMN to determine the public DNAI.

[0980] Optionally, the processor is configured to read the computer program in the memory and perform the following operations:

[0981] The DNAI is determined based on the public EAS.

[0982] Optionally, the processor is configured to read the computer program in the memory and perform the following operations:

[0983] Sending a DNS message processing rule to the EASDF of the VPLMN, wherein the DNS message processing rule is used to instruct the EASDF of the VPLMN to send the IP address of the public EAS to the terminal;

[0984] The DNS message processing rules include: a public EAS IP address and forwarding operation instruction information set to directly respond to the DNS request.

[0985] Optionally, the processor is configured to read the computer program in the memory and perform the following operations:

[0986] Sending sixth information to the EASDF of the VPLMN; the sixth information includes information for constructing an EDNS client subnet option; or, the sixth information includes information of a local DNS server associated with a public DNAI.

[0987] Optionally, the processor is configured to read the computer program in the memory and perform the following operations:

[0988] Sending a first subscription message to the NEF of the VPLMN and / or the NEF of the HPLMN, where the first subscription message is used to subscribe to a notification message of the AF traffic impact request information;

[0989] Receiving a first notification message sent by the NEF of the VPLMN and / or the NEF of the HPLMN;

[0990] The first notification message includes at least one of the following information:

[0991] Traffic correlation identification;

[0992] EAS relevance indication;

[0993] Traffic correlation indication;

[0994] The IP address of the public EAS;

[0995] Public DNAI;

[0996] FQDN;

[0997] Information about NEF.

[0998] Among them, Fig.12 In the embodiment, the bus architecture may include any number of interconnected buses and bridges, specifically linking together various circuits of one or more processors represented by processor 1210 and memory represented by memory 1220. The bus architecture may also link together various other circuits such as peripherals, voltage regulators, and power management circuits, which are well known in the art and are therefore not further described herein. The bus interface provides an interface. The transceiver 1200 may be a plurality of components, namely including a transmitter and a transceiver, providing a unit for communicating with various other devices on a transmission medium. The processor 1210 is responsible for managing the bus architecture and general processing, and the memory 1220 may store data used by the processor 1210 when performing operations.

[0999] The processor 1210 may be a central processing unit (CPU), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or a complex programmable logic device (CPLD). The processor may also adopt a multi-core architecture.

[1000] It should be noted here that the above-mentioned network device provided in the embodiment of the present application can implement all the method steps implemented by the above-mentioned method embodiment applied to SMF, and can achieve the same technical effect. The parts and beneficial effects of this embodiment that are the same as the method embodiment will not be described in detail here.

[1001] An embodiment of the present application further provides a network device, which may be a NEF, and includes: a memory, a transceiver, and a processor; wherein the memory is used to store a computer program; the transceiver is used to receive and send data under the control of the processor; and the processor is used to read the computer program in the memory and perform the following operations:

[1002] Receiving a first subscription message sent by the SMF of the VPLMN, where the first subscription message is used to subscribe to a notification message of AF traffic impact request information;

[1003] Sending a first notification message to the SMF of the VPLMN;

[1004] The first notification message includes at least one of the following information:

[1005] Traffic correlation identification;

[1006] EAS relevance indication;

[1007] Traffic correlation indication;

[1008] The IP address of the public EAS;

[1009] Public DNAI;

[1010] FQDN;

[1011] Information about NEF.

[1012] Optionally, the processor is configured to read the computer program in the memory and perform the following operations:

[1013] Sending a second subscription message to the UDR of the VPLMN, where the second subscription message is used to subscribe to a notification message of the AF traffic impact request information;

[1014] receiving a second notification message sent by the UDR of the VPLMN;

[1015] When it is determined according to the second notification message that the terminal affected by the AF request is a roaming terminal, sending the first notification message to the SMF of the VPLMN;

[1016] The second notification message includes at least one of the following:

[1017] Traffic correlation identification;

[1018] EAS relevance indication;

[1019] Traffic correlation indication;

[1020] The IP address of the public EAS;

[1021] Public DNAI;

[1022] FQDN;

[1023] Space validity conditions.

[1024] Optionally, the processor is configured to read the computer program in the memory and perform the following operations:

[1025] If the NEF of the VPLMN does not have the IP address or public DNAI of the public EAS associated with the traffic correlation identifier, a fourth request message is sent to the NEF of the HPLMN, where the fourth request message is used to request the IP address or public DNAI of the public EAS.

[1026] Optionally, the processor is configured to read the computer program in the memory and perform the following operations:

[1027] Receiving a second request message sent by the SMF of the VPLMN;

[1028] A public EAS is determined according to the second request message.

[1029] Optionally, the processor is configured to read the computer program in the memory and perform the following operations:

[1030] receiving a third request message sent by the SMF of the VPLMN;

[1031] A public DNAI is determined according to the third request message.

[1032] Optionally, the processor is configured to read the computer program in the memory and perform the following operations:

[1033] Receive the IP address of the public EAS sent by the SMF of the VPLMN, where the public EAS is discovered by the SMF of the VPLMN.

[1034] The bus architecture may include any number of interconnected buses and bridges, specifically various circuits of one or more processors represented by a processor and a memory represented by a memory linked together. The bus architecture may also link together various other circuits such as peripherals, voltage regulators, and power management circuits, which are well known in the art and are therefore not further described herein. The bus interface provides an interface. The transceiver may be a plurality of components, namely, a transmitter and a transceiver, providing a unit for communicating with various other devices on a transmission medium. The processor is responsible for managing the bus architecture and general processing, and the memory may store data used by the processor when performing operations.

[1035] The processor can be a central processing unit (CPU), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or a complex programmable logic device (CPLD), and the processor can also adopt a multi-core architecture.

[1036] It should be noted here that the above-mentioned network device provided in the embodiment of the present application can implement all the method steps implemented in the above-mentioned method embodiment applied to NEF, and can achieve the same technical effect. The parts and beneficial effects of this embodiment that are the same as the method embodiment will not be described in detail here.

[1037] like Fig.13 As shown, an embodiment of the present application further provides a network device, which may be an AF, and includes: a memory 1320, a transceiver 1300, and a processor 1310; wherein the memory 1320 is used to store a computer program; the transceiver 1300 is used to receive and send data under the control of the processor 1310; the processor 1310 is used to read the computer program in the memory and perform the following operations:

[1038] Sending a first request message to a target network element of the VPLMN;

[1039] The first request message includes at least one of the following information:

[1040] Terminal identification;

[1041] EAS relevance indication;

[1042] Traffic correlation identification;

[1043] Traffic correlation indication;

[1044] Application information;

[1045] The IP address or the candidate public DNAI of the candidate public EAS selected by the AF for the terminal.

[1046] Optionally, the processor is configured to read the computer program in the memory and perform the following operations:

[1047] Receive candidate DNAI sent by SMF;

[1048] According to the candidate DNAI, a candidate public EAS or a candidate public DNAI is selected for the terminal.

[1049] Optionally, the processor is configured to read the computer program in the memory and perform at least one of the following operations:

[1050] Sending the first request message to the SMF of the VPLMN through the NEF and / or UDR of the VPLMN;

[1051] The first request message is sent to the PCF of the VPLMN through the NEF and / or UDR of the VPLMN, so that the PCF of the VPLMN generates a PCC rule according to the first request message and sends the PCC rule to the SMF of the VPLMN.

[1052] Optionally, the application information includes at least one of the following:

[1053] At least one FQDN;

[1054] At least one EAS IP address.

[1055] Among them, Fig.13 In the embodiment, the bus architecture may include any number of interconnected buses and bridges, specifically linking together various circuits of one or more processors represented by processor 1310 and memory represented by memory 1320. The bus architecture may also link together various other circuits such as peripherals, voltage regulators, and power management circuits, which are well known in the art and are therefore not further described herein. The bus interface provides an interface. The transceiver 1300 may be a plurality of components, namely including a transmitter and a transceiver, providing a unit for communicating with various other devices on a transmission medium. The processor 1310 is responsible for managing the bus architecture and general processing, and the memory 1320 may store data used by the processor 1310 when performing operations.

[1056] The processor 1310 may be a central processing unit (CPU), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or a complex programmable logic device (CPLD). The processor may also adopt a multi-core architecture.

[1057] It should be noted here that the above-mentioned network device provided in the embodiment of the present application can implement all the method steps implemented in the above-mentioned method embodiment applied to AF, and can achieve the same technical effect. The parts and beneficial effects of this embodiment that are the same as the method embodiment will not be described in detail here.

[1058] like Fig.14As shown, an embodiment of the present application further provides a network device, which may be a PCF of a VPLMN, including: a memory 1420, a transceiver 1400, and a processor 1410; wherein the memory 1420 is used to store a computer program; the transceiver 1400 is used to receive and send data under the control of the processor 1410; the processor 1410 is used to read the computer program in the memory and perform the following operations:

[1059] receiving a first request message;

[1060] generating a PCC rule according to the first request message;

[1061] Sending the PCC rules to the SMF of the VPLMN;

[1062] The first request message includes at least one of the following information:

[1063] Terminal identification;

[1064] EAS relevance indication;

[1065] Traffic correlation identification;

[1066] Traffic correlation indication;

[1067] Application information;

[1068] The IP address or the candidate public DNAI of the candidate public EAS selected by the AF for the terminal.

[1069] The PCC rule includes at least one of the following information:

[1070] Traffic correlation identification;

[1071] EAS relevance indication;

[1072] Application information;

[1073] The IP address or the candidate public DNAI of the candidate public EAS selected by the AF for the terminal.

[1074] Optionally, the processor is configured to read the computer program in the memory and perform the following operations:

[1075] Receive a first request message sent by the NEF and / or UDR of the VPLMN.

[1076] Optionally, the application information includes at least one of the following:

[1077] At least one FQDN;

[1078] At least one EAS IP address.

[1079] Among them, Fig.14 In the embodiment, the bus architecture may include any number of interconnected buses and bridges, specifically linking together various circuits of one or more processors represented by processor 1410 and memory represented by memory 1420. The bus architecture may also link together various other circuits such as peripherals, voltage regulators, and power management circuits, which are well known in the art and are therefore not further described herein. The bus interface provides an interface. The transceiver 1400 may be a plurality of components, namely including a transmitter and a transceiver, providing a unit for communicating with various other devices on a transmission medium. The processor 1410 is responsible for managing the bus architecture and general processing, and the memory 1420 may store data used by the processor 1410 when performing operations.

[1080] The processor 1410 may be a central processing unit (CPU), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or a complex programmable logic device (CPLD). The processor may also adopt a multi-core architecture.

[1081] It should be noted here that the above-mentioned network device provided in the embodiment of the present application can implement all the method steps implemented in the above-mentioned method embodiment applied to PCF, and can achieve the same technical effect. The parts and beneficial effects that are the same as the method embodiment in this embodiment will not be described in detail here.

[1082] In addition, a specific embodiment of the present application further provides a processor-readable storage medium on which a computer program is stored, wherein the program, when executed by the processor, implements the steps of the above-mentioned edge application server discovery method, and can achieve the same technical effect. To avoid repetition, it is not repeated here. The readable storage medium can be any available medium or data storage device that can be accessed by the processor, including but not limited to magnetic storage (such as floppy disks, hard disks, magnetic tapes, magneto-optical disks (MO), etc.), optical storage (such as CD, DVD, BD, HVD, etc.), and semiconductor storage (such as ROM, EPROM, EEPROM, non-volatile memory (NAND FLASH), solid-state drive (SSD)), etc.

[1083] It should be noted that the technical solution provided in the embodiment of the present application can be applicable to a variety of systems, especially 5G systems. For example, the applicable system can be a global system of mobile communication (GSM) system, a code division multiple access (CDMA) system, a wideband code division multiple access (WCDMA) general packet radio service (GPRS) system, a long term evolution (LTE) system, a LTE frequency division duplex (FDD) system, a LTE time division duplex (TDD) system, an advanced long term evolution (LTE-A) system, a universal mobile telecommunication system (UMTS), a world-wide interoperability for microwave access (WiMAX) system, a 5G new radio (NR) system, etc. These various systems include terminal equipment and network equipment. The system may also include a core network part, such as an evolved packet system (EPS), a 5G system (5GS), etc.

[1084] The terminal device involved in the embodiment of the present application may be a device that provides voice and / or data connectivity to a user, a handheld device with a wireless connection function, or other processing devices connected to a wireless modem. In different systems, the name of the terminal device may also be different. For example, in a 5G system, the terminal device may be called a user equipment (UE). A wireless terminal device can communicate with one or more core networks (CN) via a radio access network (RAN). The wireless terminal device may be a mobile terminal device, such as a mobile phone (or a "cellular" phone) and a computer with a mobile terminal device. For example, it may be a portable, pocket-sized, handheld, computer-built-in or vehicle-mounted mobile device that exchanges language and / or data with a wireless access network. For example, personal communication service (PCS) phones, cordless phones, session initiation protocol (SIP) phones, wireless local loop (WLL) stations, personal digital assistants (PDAs) and other devices. The wireless terminal device may also be referred to as a system, a subscriber unit, a subscriber station, a mobile station, a mobile station, a remote station, an access point, a remote terminal device, an access terminal device, a user terminal device, a user agent, and a user device, but is not limited in the embodiments of the present application.

[1085] The network device involved in the embodiment of the present application may be a base station, which may include multiple cells providing services for the terminal. Depending on the specific application scenario, the base station may also be called an access point, or may be a device in the access network that communicates with the wireless terminal device through one or more sectors on the air interface, or other names. The network device may be used to interchange received air frames with Internet Protocol (IP) packets, and serve as a router between the wireless terminal device and the rest of the access network, wherein the rest of the access network may include an Internet Protocol (IP) communication network. The network device may also coordinate the attribute management of the air interface. For example, the network device involved in the embodiments of the present application may be a network device (Base Transceiver Station, BTS) in the Global System for Mobile communications (Global System for Mobile communications, GSM) or Code Division Multiple Access (Code Division Multiple Access, CDMA), or a network device (NodeB) in Wide-band Code Division Multiple Access (WCDMA), or an evolutionary network device (evolutional Node B, eNB or e-NodeB) in the long term evolution (long term evolution, LTE) system, a 5G base station (gNB) in the 5G network architecture (next generation system), or a home evolved Node B (Home evolved Node B, HeNB), a relay node, a home base station (femto), a pico base station (pico), etc., which is not limited in the embodiments of the present application. In some network structures, the network device may include a centralized unit (CU) node and a distributed unit (DU) node, and the centralized unit and the distributed unit may also be arranged geographically separately.

[1086] Network devices and terminal devices can each use one or more antennas for multiple-input multiple-output (MIMO) transmission. MIMO transmission can be single-user MIMO (SU-MIMO) or multi-user MIMO (MU-MIMO). Depending on the form and number of antenna combinations, MIMO transmission can be 2D-MIMO, 3D-MIMO, FD-MIMO or massive-MIMO, or it can be diversity transmission, precoded transmission or beamforming transmission, etc.

[1087] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage and optical storage, etc.) that contain computer-usable program code.

[1088] The present application is described with reference to the flowchart and / or block diagram of the method, device (system) and computer program product according to the embodiment of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, and the combination of the process and / or box in the flowchart and / or block diagram can be implemented by computer executable instructions. These computer executable instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device produce a device for implementing a process or multiple processes in the flowchart and / or a box or multiple boxes in the block diagram.

[1089] These processor-executable instructions may also be stored in a processor-readable memory that can direct a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the processor-readable memory produce a product including an instruction device that implements the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[1090] These processor-executable instructions may also be loaded onto a computer or other programmable data processing device so that a series of operational steps are performed on the computer or other programmable device to produce a computer-implemented process, whereby the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[1091] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A method for discovering an edge application server, characterized in that: Executed by the session management function SMF, including: Determine whether the traffic of the application supports routing to the local data network DN of the visited public land mobile network VPLMN; If the traffic of the application supports routing to the local DN of the VPLMN, it is determined that a public edge application server EAS deployed in the VPLMN or a public data network access identifier DNAI for accessing the VPLMN is selected for the terminal; If the traffic of the application does not support routing to the local DN of the VPLMN, it is determined that a public EAS deployed in the home public land mobile network HPLMN or a public DNAI for accessing the HPLMN is selected for the terminal.

2. The method according to claim 1, characterized in that The step of determining whether the traffic of the application supports routing to the local DN of the visited public land mobile network VPLMN comprises: Determining, according to the received first information, whether the traffic of the application supports routing to the local DN of the VPLMN; The first information is: a policy and charging control PCC rule sent by a policy control function PCF or a first request message sent by an application function AF; or, the first information is: a DNS query request sent by a terminal.

3. The method according to claim 2, characterized in that The PCC rule includes at least one of the following information: Traffic correlation identification; EAS relevance indication; Application information; The Internet Protocol IP address or the candidate public DNAI of the candidate public EAS selected by the AF for the terminal.

4. The method according to claim 2, characterized in that: The first request message includes at least one of the following information: Terminal identification; EAS relevance indication; Traffic correlation identification; Traffic correlation indication; Application information; The IP address or the candidate public DNAI of the candidate public EAS selected by the AF for the terminal.

5. The method according to claim 2, characterized in that: The determining, according to the received first information, whether the traffic of the application supports routing to the local DN of the VPLMN includes at least one of the following: In the case where the first information includes application information, if the application information included in the first information allows being routed to the local DN of the VPLMN, determining that traffic of the application supports being routed to the local DN of the VPLMN; If the application information included in the first information does not allow being routed to the local DN of the VPLMN, determining that the traffic of the application does not support being routed to the local DN of the VPLMN; or, In a case where the first information includes application information and an IP address of a candidate public EAS or a candidate public DNAI selected by the AF for the terminal, if the candidate public EAS is deployed in a VPLMN or the candidate public DNAI is used to access the VPLMN, and the application information and the candidate public EAS or the candidate public DNAI included in the first information are allowed to be routed to a local DN of the VPLMN, it is determined that traffic of the application supports routing to a local DN of the VPLMN; If the candidate public EAS is deployed in a VPLMN or the candidate public DNAI is used to access a VPLMN, and the application information contained in the first information and the candidate public EAS or candidate public DNAI are not allowed to be routed to the local DN of the VPLMN, it is determined that the traffic of the application does not support routing to the local DN of the VPLMN.

6. The method according to claim 5, characterized in that The application information contained in the first information allows being routed to the local DN of the VPLMN, including: The application information in the VPLMN uninstall information includes the application information in the first information; The candidate public EAS or candidate public DNAI allows being routed to the local DN of the VPLMN, including: The IP range in the VPLMN offload information includes the IP address of the candidate public EAS.

7. The method according to claim 5, characterized in that The method further comprises: In the case where the first information includes the IP address of the candidate public EAS or the candidate public DNAI selected by the AF for the terminal, if it is determined that the traffic of the application supports routing to the local DN of the VPLMN, then determining the candidate public EAS or the candidate public DNAI as the public EAS or public DNAI of the terminal; When the first information includes the IP address of the candidate public EAS or the candidate public DNAI selected by the AF for the terminal, if it is determined that the traffic of the application does not support routing to the local DN of the VPLMN, a public EAS deployed in the HPLMN or a public DNAI for accessing the HPLMN is reselected for the terminal.

8. The method according to claim 5, characterized in that The determining, according to the received first information, whether the traffic branch of the application supports routing to the local DN of the VPLMN further includes: In the case where the first information includes the IP address or candidate public DNAI of the candidate public EAS selected by the AF for the terminal, if the candidate public EAS is deployed in the HPLMN or the candidate public DNAI is used to access the HPLMN, it is determined that the traffic of the application does not support routing to the local DN of the VPLMN.

9. The method according to claim 2, characterized in that: The method further comprises: If the SMF is the SMF of the HPLMN, and the traffic of the application supports routing to the local DN of the VPLMN, sending the second information to the SMF of the VPLMN; The second information includes at least one of the following: EAS relevance indication; Traffic correlation identification; Application information; The IP address or the candidate public DNAI of the candidate public EAS selected by the AF for the terminal.

10. The method according to claim 2, characterized in that The method further comprises: If the SMF is the SMF of the VPLMN, and the traffic of the application does not support routing to the local DN of the VPLMN, sending third information to the SMF of the HPLMN; The third information includes at least one of the following: EAS relevance indication; Traffic correlation identification; Application information.

11. The method according to claim 1, characterized in that: The method further comprises: If the SMF is the SMF of the VPLMN, and it is determined that a public EAS deployed in the VPLMN or a public DNAI for accessing the VPLMN is selected for the terminal, a domain name system DNS message processing rule is sent to the edge application server discovery function EASDF of the VPLMN; The DNS message processing rule is used to indicate: when the application information contained in the DNS query meets the application information range configured by the SMF of the VPLMN, select a public EAS deployed in the VPLMN or a public DNAI for accessing the VPLMN for the terminal.

12. The method according to claim 1, characterized in that The method further comprises: determining a candidate DNAI based on the fourth information; Sending the candidate DNAI to the AF; The fourth information includes at least one of the following: Terminal location information; Available DNAI information; VPLMN uninstall information; EAS deployment information.

13. The method according to any one of claims 3 to 11, characterized in that: The application information includes at least one of the following: At least one fully qualified domain name (FQDN); At least one EAS IP address.

14. The method according to claim 2, characterized in that The step of determining whether the traffic of the application supports routing to the local DN of the visited public land mobile network VPLMN comprises: If it is determined that the FQDN carried in the DNS query request sent by the terminal is authorized by the SMF of the HPLMN, it is determined that the traffic of the application supports routing to the local DN of the VPLMN; or, If it is determined that the FQDN carried in the DNS query request sent by the terminal has not been authorized by the SMF of the HPLMN, it is determined that the traffic of the application does not support routing to the local DN of the VPLMN.

15. The method according to claim 14, characterized in that The determining that the terminal selects a public EAS deployed in the VPLMN or a public DNAI for accessing the VPLMN includes: If the FQDN carried in the DNS query request sent by the terminal matches the FQDN sent by the NEF of the VPLMN and is configured with an EAS correlation indication or a traffic correlation indication, it is determined that the terminal selects a public EAS deployed in the VPLMN or a public DNAI for accessing the VPLMN.

16. The method according to claim 14, characterized in that In the case where it is determined that the traffic of the application supports routing to the local DN of the VPLMN, the method further includes: If the notification message sent by the NEF of the VPLMN does not include the IP address of the public EAS, or the SMF of the VPLMN determines to select a new EAS for the terminal, the public EAS deployed in the VPLMN is discovered; If the SMF of the VPLMN has an IP address of a public EAS, the IP address of the public EAS is determined as the public EAS deployed in the VPLMN selected for the terminal.

17. The method according to claim 14, characterized in that In the case where it is determined that the traffic of the application does not support routing to the local DN of the VPLMN, the method further includes: If the notification message sent by the NEF of the VPLMN does not include the IP address of the public EAS, or the SMF of the VPLMN determines to select a new EAS for the terminal, at least one of the following is performed: Discover the public EAS deployed in the HPLMN; Sending fifth information to the SMF of the HPLMN, the fifth information being used to request the SMF of the HPLMN to discover a public EAS; the fifth information comprising at least one of an EAS correlation indication, a traffic correlation identifier, and an FQDN; Sending a second request message to the NEF of the VPLMN and / or the NEF of the HPLMN, where the second request message is used to request the NEF to determine a common EAS; If the SMF of the VPLMN has an IP address of a public EAS, the IP address of the public EAS is determined as the public EAS deployed in the HPLMN selected for the terminal.

18. The method according to claim 16 or 17, characterized in that The method further comprises: The IP address of the public EAS is sent to the NEF of the VPLMN and / or the NEF of the HPLMN.

19. The method according to claim 14, characterized in that In the case where traffic of the application supports routing to a local DN of the VPLMN, the method further includes: If the notification message sent by the NEF of the VPLMN does not include the public DNAI, a third request message is sent to the NEF of the VPLMN, where the third request message is used to request the NEF of the VPLMN to determine the public DNAI.

20. The method according to claim 16 or 17, characterized in that The method further comprises: The DNAI is determined based on the public EAS.

21. The method according to claim 16 or 17, characterized in that The method further comprises: Sending a DNS message processing rule to the EASDF of the VPLMN, wherein the DNS message processing rule is used to instruct the EASDF of the VPLMN to send the IP address of the public EAS to the terminal; The DNS message processing rules include: a public EAS IP address and forwarding operation instruction information set to directly respond to the DNS request.

22. The method according to claim 19, characterized in that The method further comprises: Sending sixth information to the EASDF of the VPLMN; the sixth information includes information for constructing an EDNS client subnet option; or, the sixth information includes information of a local DNS server associated with a public DNAI.

23. The method according to any one of claims 15 to 19, characterized in that The method further comprises: Sending a first subscription message to the NEF of the VPLMN and / or the NEF of the HPLMN, where the first subscription message is used to subscribe to a notification message of the AF traffic impact request information; Receiving a first notification message sent by the NEF of the VPLMN and / or the NEF of the HPLMN; The first notification message includes at least one of the following information: Traffic correlation identification; EAS relevance indication; Traffic correlation indication; The IP address of the public EAS; Public DNAI; FQDN; Information about NEF.

24. A method for discovering an edge application server, characterized in that: Executed by NEF, including: Receiving a first subscription message sent by the SMF of the VPLMN, where the first subscription message is used to subscribe to a notification message of AF traffic impact request information; Sending a first notification message to the SMF of the VPLMN; The first notification message includes at least one of the following information: Traffic correlation identification; EAS relevance indication; Traffic correlation indication; The IP address of the public EAS; Public DNAI; FQDN; Information about NEF.

25. The method according to claim 24, characterized in that The method further comprises: Sending a second subscription message to the UDR of the VPLMN, where the second subscription message is used to subscribe to a notification message of the AF traffic impact request information; receiving a second notification message sent by the UDR of the VPLMN; The sending a first notification message to the SMF of the VPLMN includes: When it is determined according to the second notification message that the terminal affected by the AF request is a roaming terminal, sending the first notification message to the SMF of the VPLMN; The second notification message includes at least one of the following: Traffic correlation identification; EAS relevance indication; Traffic correlation indication; The IP address of the public EAS; Public DNAI; FQDN; Space validity conditions.

26. The method according to claim 24, characterized in that The method further comprises: If the NEF of the VPLMN does not have the IP address or public DNAI of the public EAS associated with the traffic correlation identifier, a fourth request message is sent to the NEF of the HPLMN, where the fourth request message is used to request the IP address or public DNAI of the public EAS.

27. The method according to claim 24, characterized in that The method further comprises: Receiving a second request message sent by the SMF of the VPLMN; A public EAS is determined according to the second request message.

28. The method according to claim 24, characterized in that The method further comprises: receiving a third request message sent by the SMF of the VPLMN; A public DNAI is determined according to the third request message.

29. The method according to claim 24, characterized in that The method further comprises: Receive the IP address of the public EAS sent by the SMF of the VPLMN, where the public EAS is discovered by the SMF of the VPLMN.

30. A method for discovering an edge application server, characterized in that: Performed by AF, including: Sending a first request message to a target network element of the VPLMN; The first request message includes at least one of the following information: Terminal identification; EAS relevance indication; Traffic correlation identification; Traffic correlation indication; Application information; The IP address or the candidate public DNAI of the candidate public EAS selected by the AF for the terminal.

31. The method according to claim 30, characterized in that Before sending the first request message to the target network element of the VPLMN, the method further includes: Receive candidate DNAI sent by SMF; According to the candidate DNAI, a candidate public EAS or a candidate public DNAI is selected for the terminal.

32. The method according to claim 30, characterized in that The sending of the first request message to the target network element of the VPLMN includes at least one of the following: Sending the first request message to the SMF of the VPLMN through the network opening function NEF and / or UDR of the VPLMN; The first request message is sent to the PCF of the VPLMN through the NEF and / or UDR of the VPLMN, so that the PCF of the VPLMN generates a PCC rule according to the first request message and sends the PCC rule to the SMF of the VPLMN.

33. The method according to claim 30, characterized in that The application information includes at least one of the following: At least one FQDN; At least one EAS IP address.

34. A method for discovering an edge application server, characterized in that: Executed by the PCF of the VPLMN, including: receiving a first request message; generating a PCC rule according to the first request message; Sending the PCC rules to the SMF of the VPLMN; The first request message includes at least one of the following information: Terminal identification; EAS relevance indication; Traffic correlation identification; Traffic correlation indication; Application information; The IP address or candidate public DNAI of the candidate public EAS selected by the AF for the terminal; The PCC rule includes at least one of the following information: Traffic correlation identification; EAS relevance indication; Application information; The IP address or the candidate public DNAI of the candidate public EAS selected by the AF for the terminal.

35. The method according to claim 34, characterized in that The receiving a first request message comprises: Receive a first request message sent by the NEF and / or UDR of the VPLMN.

36. The method according to claim 34, characterized in that The application information includes at least one of the following: At least one FQDN; At least one EAS IP address.

37. A network device, characterized in that: include: Memory, transceiver, processor: Memory for storing computer programs; a transceiver for receiving and sending data under the control of the processor; A processor is configured to read the computer program in the memory and perform the following operations: Determine whether the traffic of the application supports routing to the local data network DN of the visited public land mobile network VPLMN; If the traffic of the application supports routing to the local DN of the VPLMN, it is determined that a public edge application server EAS deployed in the VPLMN or a public data network access identifier DNAI for accessing the VPLMN is selected for the terminal; If the traffic of the application does not support routing to the local DN of the VPLMN, it is determined that a public EAS deployed in the home public land mobile network HPLMN or a public DNAI for accessing the HPLMN is selected for the terminal.

38. The network device according to claim 37, characterized in that: The processor is configured to read the computer program in the memory and perform the following operations: Determining, according to the received first information, whether the traffic of the application supports routing to the local DN of the VPLMN; The first information is: a policy and charging control PCC rule sent by a policy control function PCF or a first request message sent by an application function AF; or, the first information is: a DNS query request sent by a terminal.

39. The network device according to claim 38, characterized in that: The PCC rule includes at least one of the following information: Traffic correlation identification; EAS relevance indication; Application information; The Internet Protocol IP address or the candidate public DNAI of the candidate public EAS selected by the AF for the terminal.

40. The network device according to claim 38, characterized in that The first request message includes at least one of the following information: Terminal identification; EAS relevance indication; Traffic correlation identification; Traffic correlation indication; Application information; The IP address or the candidate public DNAI of the candidate public EAS selected by the AF for the terminal.

41. The network device according to claim 38, characterized in that: The processor is configured to read the computer program in the memory and perform at least one of the following operations: In the case where the first information includes application information, if the application information included in the first information allows being routed to the local DN of the VPLMN, determining that traffic of the application supports being routed to the local DN of the VPLMN; If the application information included in the first information does not allow being routed to the local DN of the VPLMN, determining that the traffic of the application does not support being routed to the local DN of the VPLMN; or, In a case where the first information includes application information and an IP address of a candidate public EAS or a candidate public DNAI selected by the AF for the terminal, if the candidate public EAS is deployed in a VPLMN or the candidate public DNAI is used to access the VPLMN, and the application information and the candidate public EAS or the candidate public DNAI included in the first information are allowed to be routed to a local DN of the VPLMN, it is determined that traffic of the application supports routing to a local DN of the VPLMN; If the candidate public EAS is deployed in a VPLMN or the candidate public DNAI is used to access a VPLMN, and the application information contained in the first information and the candidate public EAS or candidate public DNAI are not allowed to be routed to the local DN of the VPLMN, it is determined that the traffic of the application does not support routing to the local DN of the VPLMN.

42. The network device according to claim 41, characterized in that The application information contained in the first information allows being routed to the local DN of the VPLMN, including: The application information in the VPLMN uninstall information includes the application information in the first information; The candidate public EAS or candidate public DNAI allows being routed to the local DN of the VPLMN, including: The IP range in the VPLMN offload information includes the IP address of the candidate public EAS.

43. The network device according to claim 41, characterized in that The processor is configured to read the computer program in the memory and perform the following operations: In the case where the first information includes the IP address of the candidate public EAS or the candidate public DNAI selected by the AF for the terminal, if it is determined that the traffic of the application supports routing to the local DN of the VPLMN, then determining the candidate public EAS or the candidate public DNAI as the public EAS or public DNAI of the terminal; When the first information includes the IP address of the candidate public EAS or the candidate public DNAI selected by the AF for the terminal, if it is determined that the traffic of the application does not support routing to the local DN of the VPLMN, a public EAS deployed in the HPLMN or a public DNAI for accessing the HPLMN is reselected for the terminal.

44. The network device according to claim 41, characterized in that The processor is configured to read the computer program in the memory and perform the following operations: In the case where the first information includes the IP address or candidate public DNAI of the candidate public EAS selected by the AF for the terminal, if the candidate public EAS is deployed in the HPLMN or the candidate public DNAI is used to access the HPLMN, it is determined that the traffic of the application does not support routing to the local DN of the VPLMN.

45. The network device according to claim 38, characterized in that The processor is configured to read the computer program in the memory and perform the following operations: If the SMF is the SMF of the HPLMN, and the traffic of the application supports routing to the local DN of the VPLMN, sending the second information to the SMF of the VPLMN; The second information includes at least one of the following: EAS relevance indication; Traffic correlation identification; Application information; The IP address or the candidate public DNAI of the candidate public EAS selected by the AF for the terminal.

46. ​​The network device according to claim 38, characterized in that The processor is configured to read the computer program in the memory and perform the following operations: If the SMF is the SMF of the VPLMN, and the traffic of the application does not support routing to the local DN of the VPLMN, sending third information to the SMF of the HPLMN; The third information includes at least one of the following: EAS relevance indication; Traffic correlation identification; Application information.

47. The network device according to claim 37, characterized in that: The processor is configured to read the computer program in the memory and perform the following operations: If the SMF is the SMF of the VPLMN, and it is determined that a public EAS deployed in the VPLMN or a public DNAI for accessing the VPLMN is selected for the terminal, a DNS message processing rule is sent to the EASDF of the VPLMN; The DNS message processing rule is used to indicate: when the application information contained in the DNS query meets the application information range configured by the SMF of the VPLMN, select a public EAS deployed in the VPLMN or a public DNAI for accessing the VPLMN for the terminal.

48. The network device according to claim 37, characterized in that The processor is configured to read the computer program in the memory and perform the following operations: determining a candidate DNAI based on the fourth information; Sending the candidate DNAI to the AF; The fourth information includes at least one of the following: Terminal location information; Available DNAI information; VPLMN uninstall information EAS deployment information.

49. The network device according to any one of claims 39 to 47, characterized in that: The application information includes at least one of the following: At least one fully qualified domain name (FQDN); At least one EAS IP address.

50. The network device according to claim 38, characterized in that The processor is configured to read the computer program in the memory and perform the following operations: If it is determined that the FQDN carried in the DNS query request sent by the terminal is authorized by the SMF of the HPLMN, it is determined that the traffic of the application supports routing to the local DN of the VPLMN; or, If it is determined that the FQDN carried in the DNS query request sent by the terminal has not been authorized by the SMF of the HPLMN, it is determined that the traffic of the application does not support routing to the local DN of the VPLMN.

51. The network device according to claim 50, characterized in that The processor is configured to read the computer program in the memory and perform the following operations: If the FQDN carried in the DNS query request sent by the terminal matches the FQDN sent by the NEF of the VPLMN and is configured with an EAS correlation indication or a traffic correlation indication, it is determined that the terminal selects a public EAS deployed in the VPLMN or a public DNAI for accessing the VPLMN.

52. The network device according to claim 50, characterized in that The processor is configured to read the computer program in the memory and perform the following operations: If the notification message sent by the NEF of the VPLMN does not include the IP address of the public EAS, or the SMF of the VPLMN determines to select a new EAS for the terminal, the public EAS deployed in the VPLMN is discovered; If the SMF of the VPLMN has an IP address of a public EAS, the IP address of the public EAS is determined as the public EAS deployed in the VPLMN selected for the terminal.

53. The network device according to claim 50, characterized in that The processor is configured to read the computer program in the memory and perform the following operations: If the notification message sent by the NEF of the VPLMN does not include the IP address of the public EAS, or the SMF of the VPLMN determines to select a new EAS for the terminal, at least one of the following is performed: Discover the public EAS deployed in the HPLMN; Sending fifth information to the SMF of the HPLMN, the fifth information being used to request the SMF of the HPLMN to discover a public EAS; the fifth information comprising at least one of an EAS correlation indication, a traffic correlation identifier, and an FQDN; Sending a second request message to the NEF of the VPLMN and / or the NEF of the HPLMN, where the second request message is used to request the NEF to determine a common EAS; If the SMF of the VPLMN has an IP address of a public EAS, the IP address of the public EAS is determined as the public EAS deployed in the HPLMN selected for the terminal.

54. The network device according to claim 52 or 53, characterized in that: The processor is configured to read the computer program in the memory and perform the following operations: The IP address of the public EAS is sent to the NEF of the VPLMN and / or the NEF of the HPLMN.

55. The network device according to claim 50, characterized in that The processor is configured to read the computer program in the memory and perform the following operations: If the notification message sent by the NEF of the VPLMN does not include the public DNAI, a third request message is sent to the NEF of the VPLMN, where the third request message is used to request the NEF of the VPLMN to determine the public DNAI.

56. The network device according to claim 52 or 53, characterized in that: The processor is configured to read the computer program in the memory and perform the following operations: The DNAI is determined based on the public EAS.

57. The network device according to claim 52 or 53, characterized in that: The processor is configured to read the computer program in the memory and perform the following operations: Sending a DNS message processing rule to the EASDF of the VPLMN, wherein the DNS message processing rule is used to instruct the EASDF of the VPLMN to send the IP address of the public EAS to the terminal; The DNS message processing rules include: a public EAS IP address and forwarding operation instruction information set to directly respond to the DNS request.

58. The network device according to claim 55, characterized in that The processor is configured to read the computer program in the memory and perform the following operations: Sending sixth information to the EASDF of the VPLMN; the sixth information includes information for constructing an EDNS client subnet option; or, the sixth information includes information of a local DNS server associated with a public DNAI.

59. The network device according to any one of claims 51 to 55, characterized in that: The processor is configured to read the computer program in the memory and perform the following operations: Sending a first subscription message to the NEF of the VPLMN and / or the NEF of the HPLMN, where the first subscription message is used to subscribe to a notification message of the AF traffic impact request information; Receiving a first notification message sent by the NEF of the VPLMN and / or the NEF of the HPLMN; The first notification message includes at least one of the following information: Traffic correlation identification; EAS relevance indication; Traffic correlation indication; The IP address of the public EAS; Public DNAI; FQDN; Information about NEF.

60. A network device, characterized in that: include: Memory, transceiver, processor: Memory for storing computer programs; a transceiver for receiving and sending data under the control of the processor; A processor is configured to read the computer program in the memory and perform the following operations: Receiving a first subscription message sent by the SMF of the VPLMN, where the first subscription message is used to subscribe to a notification message of AF traffic impact request information; Sending a first notification message to the SMF of the VPLMN; The first notification message includes at least one of the following information: Traffic correlation identification; EAS relevance indication; Traffic correlation indication; The IP address of the public EAS; Public DNAI; FQDN; Information about NEF.

61. The network device according to claim 60, characterized in that The processor is configured to read the computer program in the memory and perform the following operations: Sending a second subscription message to the UDR of the VPLMN, where the second subscription message is used to subscribe to a notification message of the AF traffic impact request information; receiving a second notification message sent by the UDR of the VPLMN; When it is determined according to the second notification message that the terminal affected by the AF request is a roaming terminal, sending the first notification message to the SMF of the VPLMN; The second notification message includes at least one of the following: Traffic correlation identification; EAS relevance indication; Traffic correlation indication; The IP address of the public EAS; Public DNAI; FQDN; Space validity conditions.

62. The network device according to claim 60, characterized in that The processor is configured to read the computer program in the memory and perform the following operations: If the NEF of the VPLMN does not have the IP address or public DNAI of the public EAS associated with the traffic correlation identifier, a fourth request message is sent to the NEF of the HPLMN, where the fourth request message is used to request the IP address or public DNAI of the public EAS.

63. The network device according to claim 60, characterized in that The processor is configured to read the computer program in the memory and perform the following operations: Receiving a second request message sent by the SMF of the VPLMN; A public EAS is determined according to the second request message.

64. The network device according to claim 60, characterized in that The processor is configured to read the computer program in the memory and perform the following operations: receiving a third request message sent by the SMF of the VPLMN; A public DNAI is determined according to the third request message.

65. The network device according to claim 60, characterized in that The processor is configured to read the computer program in the memory and perform the following operations: Receive the IP address of the public EAS sent by the SMF of the VPLMN, where the public EAS is discovered by the SMF of the VPLMN.

66. A network device, characterized in that: include: Memory, transceiver, processor: Memory for storing computer programs; a transceiver for receiving and sending data under the control of the processor; A processor is configured to read the computer program in the memory and perform the following operations: Sending a first request message to a target network element of the VPLMN; The first request message includes at least one of the following information: Terminal identification; EAS relevance indication; Traffic correlation identification; Traffic correlation indication; Application information; The IP address or the candidate public DNAI of the candidate public EAS selected by the AF for the terminal.

67. The network device according to claim 66, characterized in that The processor is configured to read the computer program in the memory and perform the following operations: Receive candidate DNAI sent by SMF; According to the candidate DNAI, a candidate public EAS or a candidate public DNAI is selected for the terminal.

68. The network device according to claim 66, characterized in that The processor is configured to read the computer program in the memory and perform at least one of the following operations: Sending the first request message to the SMF of the VPLMN through the NEF and / or UDR of the VPLMN; The first request message is sent to the PCF of the VPLMN through the NEF and / or UDR of the VPLMN, so that the PCF of the VPLMN generates a PCC rule according to the first request message and sends the PCC rule to the SMF of the VPLMN.

69. The network device according to claim 66, characterized in that The application information includes at least one of the following: At least one FQDN; At least one EAS IP address.

70. A network device, characterized in that: include: Memory, transceiver, processor: Memory for storing computer programs; a transceiver for receiving and sending data under the control of the processor; A processor is configured to read the computer program in the memory and perform the following operations: receiving a first request message; generating a PCC rule according to the first request message; Sending the PCC rules to the SMF of the VPLMN; The first request message includes at least one of the following information: Terminal identification; EAS relevance indication; Traffic correlation identification; Traffic correlation indication; Application information; The IP address or candidate public DNAI of the candidate public EAS selected by the AF for the terminal; The PCC rule includes at least one of the following information: Traffic correlation identification; EAS relevance indication; Application information; The IP address or the candidate public DNAI of the candidate public EAS selected by the AF for the terminal.

71. The network device according to claim 70, characterized in that The processor is configured to read the computer program in the memory and perform the following operations: Receive a first request message sent by the NEF and / or UDR of the VPLMN.

72. The network device according to claim 70, characterized in that The application information includes at least one of the following: At least one FQDN; At least one EAS IP address.

73. A discovery device for an edge application server, characterized in that: include: A first determination unit, configured to determine whether the traffic of the application supports routing to the local DN of the VPLMN; A second determining unit is configured to determine, if the traffic of the application supports routing to the local DN of the VPLMN, to select a public edge application server EAS deployed in the VPLMN or a public data network access identifier DNAI for accessing the VPLMN for the terminal; If the traffic of the application does not support routing to the local DN of the VPLMN, it is determined that a public EAS deployed in the home public land mobile network HPLMN or a public DNAI for accessing the HPLMN is selected for the terminal.

74. A discovery device for an edge application server, characterized in that: include: A third receiving unit is used to receive a first subscription message sent by the SMF of the VPLMN, where the first subscription message is used to subscribe to a notification message of the AF traffic impact request information; A seventh sending unit, configured to send a first notification message to the SMF of the VPLMN; The first notification message includes at least one of the following information: Traffic correlation identification; EAS relevance indication; Traffic correlation indication; The IP address of the public EAS; Public DNAI; FQDN; Information about NEF.

75. A discovery device for an edge application server, characterized in that: include: A first sending unit, configured to send a first request message to a target network element of the VPLMN; The first request message includes at least one of the following information: Terminal identification; EAS relevance indication; Traffic correlation identification; Traffic correlation indication; Application information; The IP address or the candidate public DNAI of the candidate public EAS selected by the AF for the terminal.

76. A discovery device for an edge application server, characterized in that: include: A first receiving unit, configured to receive a first request message; A generating unit, configured to generate a PCC rule according to the first request message; A second sending unit, configured to send the PCC rule to the SMF of the VPLMN; The first request message includes at least one of the following information: Terminal identification; EAS relevance indication; Traffic correlation identification; Traffic correlation indication; Application information; The IP address or candidate public DNAI of the candidate public EAS selected by the AF for the terminal; The PCC rule includes at least one of the following information: Traffic correlation identification; EAS relevance indication; Application information; The IP address or the candidate public DNAI of the candidate public EAS selected by the AF for the terminal.

77. A processor-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, it implements the steps of the edge application server discovery method as described in any one of claims 1 to 23, or implements the steps of the edge application server discovery method as described in any one of claims 24 to 29, or implements the steps of the edge application server discovery method as described in any one of claims 30 to 33, or implements the steps of the edge application server discovery method as described in any one of claims 34 to 36.

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