DNS information processing method and apparatus, address overlapping processing method and apparatus, and communication device

Abstract

The present disclosure provides a DNS information processing method and apparatus, an address overlapping processing method and apparatus, a communication device and a storage medium. The DNS information processing method comprises: a second network function adds second information to third information on the basis of first information and sends same to a third network function; and the third network function determines, on the basis of at least one second DNS processing rule, a target DNS processing rule corresponding to the second information, and sends DNS query information to a target DNS server on the basis of the target DNS processing rule. The method further comprises: a first network function sends or reports fifth information to a fourth network function on the basis of received fourth information, wherein the fifth information is used for indicating that address overlapping occurs, and triggering the fourth network function to allocate a new UE address to a terminal and perform a PDU session modification process.

Description

DNS information processing method, address overlap processing method, device, and communication equipment

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese Patent Application No. 202311016315.0 filed in China on August 11, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to the field of communication technology, and in particular to a DNS information processing method and an address overlap processing method, apparatus, communication equipment, and storage medium. Background Art

[0004] In roaming scenarios, for some low-latency services, the terminal also needs edge computing access at the visited location. When the terminal performs edge computing access at the visited location, the terminal sends a Domain Name System (DNS) query message. After the Visit-Edge Application Server Discovery Function (V-EASDF) receives the DNS query message, it matches the DNS handling rules based on the Internet Protocol (IP) address of the terminal carried in the DNS query message, and then parses and forwards the DNS query message based on the matched DNS handling rules. However, when multiple Data Network Names (DNN) use the same IP range, multiple terminals may use the same IP address. In this case, the DNS query information of multiple terminals may have the same source address and destination address. The source address is the IP address of the terminal, and the destination address is the IP address of the V-EASDF. This will cause the V-EASDF to be unable to match the correct DNS processing rules for the terminal's DNS query information, further causing the DNS query information to be unable to be correctly parsed and forwarded.

[0005] Summary of the Invention

[0006] To solve the above technical problems, the embodiments of the present disclosure provide a DNS information processing method and an address overlap processing method, apparatus, communication equipment, chip, and computer-readable storage medium.

[0007] The DNS information processing method provided by the embodiment of the present disclosure includes:

[0008] The first network function sends first information to the second network function, where the first information is used to indicate that DNS query information of a first protocol data unit (PDU) session needs to carry second information, where the second information is used to determine a target DNS processing rule.

[0009] The DNS information processing method provided by the embodiment of the present disclosure includes:

[0010] The second network function receives third information sent by the terminal;

[0011] The second network function adds the second information to the third information based on the first information and sends the second information to the third network function; wherein the second information is used by the third network function to determine the target DNS processing rule.

[0012] The DNS information processing method provided by the embodiment of the present disclosure includes:

[0013] The third network function receives the DNS query information carrying the second information sent by the second network function;

[0014] The third network function determines a target DNS processing rule corresponding to the second information based on at least one second DNS processing rule, and sends the DNS query information to a target DNS server based on the target DNS processing rule.

[0015] The method for handling address overlap provided by the embodiment of the present disclosure includes:

[0016] The first network function sends or reports fifth information to the fourth network function based on the received fourth information, where the fifth information is used to indicate that address overlap occurs, triggering the fourth network function to assign a new UE address to the terminal and perform a PDU session modification process.

[0017] The method for handling address overlap provided by the embodiment of the present disclosure includes:

[0018] The second network function receives sixth information sent by the first network function, where the sixth information is used to configure the second network function to perform a first operation; wherein the first operation includes: the second network function detecting address overlap, and / or the second network function detecting that DNS query information from different PDU sessions has the same source address.

[0019] The DNS information processing device provided by the embodiment of the present disclosure is applied to a first network function, and the device includes:

[0020] A sending unit is used to send first information to the second network function, where the first information is used to indicate that the DNS query information of the first protocol data unit PDU session needs to carry second information, and the second information is used to determine a target DNS processing rule.

[0021] The DNS information processing device provided by the embodiment of the present disclosure is applied to a second network function, and the device includes:

[0022] a receiving unit, configured to receive third information sent by a terminal;

[0023] a processing unit, configured to add the second information to the third information based on the first information;

[0024] A sending unit is configured to send the third information with the second information added thereto to a third network function; wherein the second information is used by the third network function to determine a target DNS processing rule.

[0025] The DNS information processing device provided in the embodiment of the present disclosure is applied to a third network function, and the device includes:

[0026] a receiving unit, configured to receive DNS query information carrying second information sent by the second network function;

[0027] a processing unit, configured to determine a target DNS processing rule corresponding to the second information based on at least one second DNS processing rule;

[0028] A sending unit is used to send the DNS query information to a target DNS server based on the target DNS processing rule.

[0029] The address overlap processing device provided by the embodiment of the present disclosure is applied to a first network function, and the device includes:

[0030] A sending unit is configured to send or report fifth information to a fourth network function based on the received fourth information, where the fifth information is used to indicate that an address overlap occurs, triggering the fourth network function to assign a new UE address to the terminal and perform a PDU session modification process.

[0031] The address overlap processing device provided in the embodiment of the present disclosure is applied to a second network function, and the device includes:

[0032] A receiving unit, configured to receive sixth information sent by the first network function, where the sixth information is used to configure the second network function to perform a first operation; wherein the first operation includes: the second network function detecting address overlap, and / or the second network function detecting that DNS query information from different PDU sessions has the same source address.

[0033] The communication device provided by the embodiment of the present disclosure includes: a processor and a memory, the memory is used to store a computer program, and the processor is used to call and run the computer program stored in the memory to execute any one of the above-mentioned DNS information processing methods.

[0034] The chip provided by the embodiment of the present disclosure includes: a processor, which is used to call and run a computer program from a memory, so that a device equipped with the chip executes any one of the above-mentioned DNS information processing methods.

[0035] The computer-readable storage medium provided by the embodiments of the present disclosure is used to store a computer program, and the computer program enables a computer to execute any one of the above methods.

[0036] The technical solution of the embodiment of the present disclosure, on the one hand, realizes carrying second information in DNS query information by introducing a new mechanism, and the second information can be used to match the DNS query information to the correct target DNS processing rule, thereby ensuring that the DNS query information can be correctly resolved and forwarded. On the other hand, by introducing a new mechanism, when address overlap occurs, a new user equipment (UE) address can be assigned to the terminal and a protocol data unit (PDU) session modification process can be performed, thereby ensuring that the UE address of the terminal is non-overlapping, and the non-overlapping UE address can be used to match the DNS query information to the correct target DNS processing rule, thereby ensuring that the DNS query information can be correctly resolved and forwarded. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] FIG1 is a flowchart of a DNS information processing method according to an embodiment of the present disclosure;

[0038] FIG2 is a second flow chart of the DNS information processing method provided by an embodiment of the present disclosure;

[0039] FIG3 is a third flow chart of the DNS information processing method provided by an embodiment of the present disclosure;

[0040] FIG4 is a fourth flow chart of a DNS information processing method according to an embodiment of the present disclosure;

[0041] FIG5 is a fifth flow chart of a DNS information processing method according to an embodiment of the present disclosure;

[0042] FIG6 is a flowchart of a method for handling address overlap provided by an embodiment of the present disclosure;

[0043] FIG7 is a second flow chart of a method for handling address overlap provided by an embodiment of the present disclosure;

[0044] FIG8 is a schematic diagram of the structure of a DNS information processing device according to an embodiment of the present disclosure;

[0045] FIG9 is a second schematic diagram of the structure of the DNS information processing device provided in an embodiment of the present disclosure;

[0046] FIG10 is a third schematic diagram of the structure of the DNS information processing device provided in an embodiment of the present disclosure;

[0047] FIG11 is a schematic diagram of the first structure of an address overlap processing device provided in an embodiment of the present disclosure;

[0048] FIG12 is a second schematic diagram of the structure of the address overlap processing device provided in an embodiment of the present disclosure;

[0049] FIG13 is a schematic structural diagram of a communication device provided in an embodiment of the present disclosure;

[0050] FIG14 is a schematic structural diagram of a chip according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0051] The following will describe the technical solutions in the embodiments of the present disclosure in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present disclosure, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present disclosure without making any creative efforts shall fall within the scope of protection of the present disclosure.

[0052] It should be noted that the terms "system" and "network" are often used interchangeably in this article. The term "and / or" in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the previous and next associated objects are in an "or" relationship. It should also be understood that the "indication" mentioned in the embodiments of the present disclosure can be a direct indication, an indirect indication, or an indication of an association relationship. For example, A indicates B, which can mean that A directly indicates B, for example, B can be obtained through A; it can also mean that A indirectly indicates B, for example, A indicates C, and B can be obtained through C; it can also mean that there is an association relationship between A and B. It should also be understood that the "correspondence" mentioned in the embodiments of the present disclosure can mean that there is a direct correspondence or an indirect correspondence between the two, or it can mean that there is an association relationship between the two.

[0053] The technical solutions of the embodiments of the present disclosure can be applied to 5th Generation Mobile Communication Technology (5G) networks, but are not limited thereto. They can also be applied to other types of networks, such as 6th Generation Mobile Communication Technology (6G) networks and future communication networks. It should be noted that most of the examples in the embodiments of the present disclosure are based on 5G networks, but are not limited thereto. In other types of networks, the network function names in the 5G network can be replaced with network function names in other types of networks according to their functions.

[0054] In 5G networks, in addition to terminals (also known as user equipment (UE)), the network functions involved include: Radio Access Network (RAN), User Plane Function (UPF), Data Network (DN), Access and Mobility Management Function (AMF), Session Management Function (SMF), Policy Control Function (PCF), Application Function (AF), Authentication Server Function (AUSF), Unified Data Management (UDM), etc. As 5G networks evolve or change, other network functions may be included in 5G networks, and the names of network functions in 5G networks may also change.

[0055] The technical solution of the disclosed embodiments provides a method for DNS information processing in roaming scenarios. In roaming scenarios, the name of the network function at the home location can be recorded as H-network function, where H stands for home, such as H-UPF, H-SMF, and H-PCF. The name of the network function at the visited location can be recorded as V-network function, where V stands for visit, such as V-UPF and V-SMF.

[0056] To facilitate understanding of the technical solutions of the embodiments of the present disclosure, the first network function, the second network function, the third network function, and the fourth network function involved in the embodiments of the present disclosure are described below.

[0057] In some embodiments, the first network function is a V-SMF.

[0058] In some implementations, the second network function is a V-UPF.

[0059] In some embodiments, the third network function is V-EASDF.

[0060] In some implementations, the fourth network function is an H-SMF.

[0061] FIG1 is a flowchart of a DNS information processing method according to an embodiment of the present disclosure. The method is applied to a first network function side. As shown in FIG1 , the method includes:

[0062] Step 101: A first network function sends first information to a second network function, where the first information is used to indicate that DNS query information of a first PDU session needs to carry second information, where the second information is used to determine a target DNS processing rule.

[0063] In one example, the V-SMF sends first information to the V-UPF, where the first information is used to indicate that the DNS query information of the first PDU session needs to carry second information.

[0064] In some embodiments, the first information may be N4 session establishment request information, which carries N4 rules, including packet detection rules (PDR) and / or forwarding rules (FAR). The N4 rule, PDR, or FAR carries an indication information, which is used to indicate that the DNS query information of the first PDU session needs to carry the second information.

[0065] In some embodiments, the second information includes a DNN, which is used to determine a target DNS processing rule.

[0066] Here, each DNS processing rule includes a DNN, and the corresponding target DNS processing rule can be matched through the DNN.

[0067] In some implementations, the second information includes a DNS processing rule identifier (ID), and the DNS processing rule ID is used to determine a target DNS processing rule.

[0068] Here, each DNS processing rule includes a DNS processing rule ID, and the DNS processing rule ID can be used to match the corresponding target DNS processing rule.

[0069] In some embodiments, the second information includes a DNN and a DNS processing rule ID, and the DNN and the DNS processing rule ID are used to determine the target DNS processing rule.

[0070] Here, each DNS processing rule includes a DNN and a DNS processing rule ID, and the corresponding target DNS processing rule can be matched through the DNN and the DNS processing rule ID.

[0071] In some embodiments, the method further comprises the following steps:

[0072] Step 102: The first network function adds the second information to at least one first DNS processing rule, and sends the obtained at least one second DNS processing rule to the third network function; wherein the target DNS processing rule is one of the at least one second DNS processing rule.

[0073] In some embodiments, before step 102 , the method further includes the following steps: the first network function receives at least one first DNS processing rule sent by the fourth network function.

[0074] In one example, the V-SMF receives at least one first DNS processing rule sent by the H-SMF. The V-SMF adds second information to the at least one first DNS processing rule to obtain at least one second DNS processing rule. It can be understood that the second DNS processing rule has the second information added to the first DNS processing rule. The V-SMF sends the at least one second DNS processing rule to the V-EASDF. As one implementation, the second information includes a DNN. As another implementation, the second information includes a DNS processing rule ID. As yet another implementation, the second information includes a DNN and a DNS processing rule ID.

[0075] FIG2 is a second flow chart of a DNS information processing method provided by an embodiment of the present disclosure, which is applied to the second network function side. As shown in FIG2 , the method includes:

[0076] Step 201: The second network function receives third information sent by a terminal.

[0077] In an example, the V-UPF receives third information sent by the terminal.

[0078] In some implementations, the third information may be DNS query information, which may also be referred to as a DNS request. The DNS query information carries the first domain name and is used to request the first IP address corresponding to the first domain name.

[0079] Step 202: The second network function adds second information to the third information based on the first information, and sends the second information to the third network function; wherein the second information is used by the third network function to determine the target DNS processing rule.

[0080] In some embodiments, before step 202, the method further includes the following steps: the second network function receives first information sent by the first network function, where the first information is used to indicate that the DNS query information of the first PDU session needs to carry the second information.

[0081] In one example, the V-UPF receives first information sent by the V-SMF, where the first information is used to indicate that the DNS query information of the first PDU session needs to carry the second information. After receiving third information sent by the terminal, the V-UPF adds the second information to the third information based on the first information and sends it to the V-EASDF.

[0082] In some embodiments, the first information may be N4 session establishment request information, which carries N4 rules, including packet detection rules (PDR) and / or forwarding rules (FAR). The N4 rule, PDR, or FAR carries an indication information, which is used to indicate that the DNS query information of the first PDU session needs to carry the second information.

[0083] In some embodiments, the second information includes a DNN, which is used to determine a target DNS processing rule.

[0084] Here, each DNS processing rule contains a DNN, and the corresponding target DNS processing rule can be matched through the DNN.

[0085] In some implementations, the second information includes a DNS processing rule ID, and the DNS processing rule ID is used to determine a target DNS processing rule.

[0086] Here, each DNS processing rule includes a DNS processing rule ID, and the DNS processing rule ID can be used to match the corresponding target DNS processing rule.

[0087] In some embodiments, the second information includes a DNN and a DNS processing rule ID, and the DNN and the DNS processing rule ID are used to determine the target DNS processing rule.

[0088] Here, each DNS processing rule includes a DNN and a DNS processing rule ID, and the corresponding target DNS processing rule can be matched through the DNN and the DNS processing rule ID.

[0089] In some implementations, in the above solution, the second network function adds the second information to the third information based on the first information, which can be implemented by the following mechanism:

[0090] The second network function determines the PDU session associated with the third information and confirms whether the PDU session is the first PDU session indicated in the first information; if it is the first PDU session indicated in the first information, detects whether the third information is DNS query information; if it is DNS query information, adds the second information indicated by the first information to the third information.

[0091] In one example, after receiving the third information, the V-UPF determines the PDU session associated with the third information based on the tunnel ID of the third information; the V-UPF confirms whether the PDU session associated with the third information is the first PDU session indicated in the first information; if it is the first PDU session indicated in the first information, the V-UPF further detects whether the third information is DNS query information (the type of the third information can be determined through the packet header of the third information, thereby determining whether the third information is DNS query information); if the third information is DNS query information, the V-UPF adds the second information indicated by the first information to the third information.

[0092] In some embodiments, the second network function may add the second information to the IP header of the third information. In other embodiments, the second network function may add the second information to the EDNS Client Subnet (ECSN) field of the third information, specifically, the second information may be added to the ECS option of the third information.

[0093] FIG3 is a third flow chart of a DNS information processing method provided by an embodiment of the present disclosure, which is applied to a third network function side. As shown in FIG3 , the method includes:

[0094] Step 301: A third network function receives DNS query information carrying second information sent by a second network function.

[0095] In an example, the V-EASDF receives DNS query information carrying the second information sent by the V-UPF.

[0096] In some embodiments, the second information includes a DNN, which is used to determine a target DNS processing rule.

[0097] In some implementations, the second information includes a DNS processing rule ID, and the DNS processing rule ID is used to determine a target DNS processing rule.

[0098] In some embodiments, the second information includes a DNN and a DNS processing rule ID, and the DNN and the DNS processing rule ID are used to determine the target DNS processing rule.

[0099] Step 302: The third network function determines a target DNS processing rule corresponding to the second information based on at least one second DNS processing rule.

[0100] In some implementations, before step 302 , the method further includes the following steps: the third network function receives at least one second DNS processing rule sent by the first network function.

[0101] In one example, the V-EASDF receives at least one second DNS processing rule sent by the V-SMF; based on the at least one second DNS processing rule, the V-EASDF determines a target DNS processing rule corresponding to the second information carried in the DNS query information.

[0102] Here, the at least one second DNS processing rule is obtained by the V-SMF adding the second information to the at least one first DNS processing rule. It can be understood that the second DNS processing rule is added with the second information relative to the first DNS processing rule.

[0103] In an example, the second information includes a DNN, each second DNS processing rule includes a DNN, and the corresponding target DNS processing rule can be matched from at least one second DNS processing rule through the DNN.

[0104] In an example, the second information includes a DNS processing rule ID. Each second DNS processing rule includes a DNS processing rule ID. The DNS processing rule ID can be used to match a corresponding target DNS processing rule from at least one second DNS processing rule.

[0105] In one example, the second information includes a DNN and a DNS processing rule ID, each second DNS processing rule includes a DNN and a DNS processing rule ID, and the corresponding target DNS processing rule can be matched from at least one second DNS processing rule through the DNN and DNS processing rule ID.

[0106] Step 303: The third network function sends the DNS query information to the target DNS server based on the target DNS processing rule.

[0107] In one example, the V-EASDF sends the DNS query information to the target DNS server based on the target DNS processing rules.

[0108] In some embodiments, the method further comprises the following steps:

[0109] Step 304: The third network function receives the DNS response information sent by the target DNS server, where the DNS response information includes the first IP address corresponding to the first domain name in the DNS query information; and sends the DNS response information to the terminal.

[0110] In an example, the V-EASDF receives DNS response information sent by the target DNS server, and sends the DNS response information to the terminal.

[0111] In some implementations, the third network function sending the DNS response information to the terminal may be implemented by the following mechanism: the third network function sends the DNS response information to the terminal based on the second information and / or the IP address of the terminal.

[0112] FIG4 is a fourth flow chart of a DNS information processing method provided by an embodiment of the present disclosure. As shown in FIG4 , the method includes:

[0113] Step 401: The V-SMF sends first information to the V-UPF, where the first information is used to indicate that the DNS query information of the first PDU session needs to carry the DNN.

[0114] Step 402: The V-SMF sends at least one second DNS processing rule to the V-EASDF, where each second DNS processing rule includes a DNN.

[0115] Step 403: The terminal sends third information to the V-UPF.

[0116] Step 404: After receiving the third information, the V-UPF confirms whether the PDU session associated with the third information is the first PDU session indicated in the first information; if it is the first PDU session indicated in the first information, it further detects whether the third information is DNS query information; if the third information is DNS query information, the DNN indicated by the first information is added to the third information to obtain DNS query information carrying the DNN.

[0117] Step 405: The V-UPF sends the DNS query information carrying the DNN to the V-EASDF.

[0118] Step 406: The V-EASDF matches a corresponding target DNS processing rule in at least one second DNS processing rule according to the DNN carried in the DNS query information.

[0119] Step 407: The V-EASDF sends the DNS query information to the target DNS server based on the target DNS processing rule.

[0120] Step 408: The target DNS server sends a DNS response message to the V-EASDF.

[0121] Step 409: The V-EASDF sends the DNS response information to the terminal according to the DNN and / or the IP address of the terminal.

[0122] The technical solutions of the embodiments of the present disclosure are further illustrated below with reference to specific application examples.

[0123] FIG5 is a fifth flow chart of a DNS information processing method provided by an embodiment of the present disclosure. As shown in FIG5 , the method includes:

[0124] Step 501: The UE registers with the network.

[0125] Step 502: A PDU session is established between the UE and the network.

[0126] Step 503: The V-SMF sends an N4 session establishment request message to the V-UPF. The message carries an indication message, which is used to indicate that the DNS query information of the first PDU session needs to carry the DNN.

[0127] Step 504: The V-UPF sends an N4 session establishment response message to the V-SMF.

[0128] Step 505: The V-SMF creates a DNS context and sends at least one second DNS processing rule to the V-EASDF.

[0129] Here, each second DNS processing rule carries a DNN.

[0130] Step 506: The UE sends a DNS query request message to the V-UPF.

[0131] Step 507: The V-UPF confirms that the PDU session associated with the DNS query request information is the first PDU session indicated in step 503, further detects that the DNS query request information is DNS query request information, and adds the DNN indicated in step 503 to the DNS query request information (this step is referred to as DNS processing in Figure 5).

[0132] Step 508: The V-UPF sends the DNS query request information with the DNN added to the V-EASDF.

[0133] Step 509: The V-EASDF matches a corresponding target DNS processing rule in at least one second DNS processing rule according to the DNN in the DNS query request information, and forwards the DNS query request information to the DNS server based on the target DNS processing rule.

[0134] Step 510: The V-SMF executes an uplink classifier (ULCL) insertion process.

[0135] Step 511: The DNS server returns the DNS response information to the V-EASDF, and the V-EASDF sends the DNS response information to the UE according to the DNN and the IP address of the UE.

[0136] When multiple DNNs use the same IP range, multiple terminals may use the same IP address. In this case, the DNS query information of the terminal carries the same source address (i.e., UE address) and destination address (i.e., V-EASDF address). By adopting the technical solution of the above-mentioned embodiment of the present disclosure, DNN is added to the DNS query information, so that the DNS query information can match the correct target DNS processing rules, ensuring that the DNS query information can be correctly resolved and forwarded. However, the DNS response information will also carry the same source address and destination address, and this address conflict needs to be resolved. To this end, the following technical solution of the embodiment of the present disclosure is proposed.

[0137] It should be noted that the "address overlap" described in the embodiments of the present disclosure may also be replaced by "address conflict." Address overlap refers to the overlap of terminal IP addresses (also referred to as UE addresses or UE IP addresses).

[0138] FIG6 is a flowchart of a method for handling address overlap provided by an embodiment of the present disclosure. As shown in FIG6 , the method includes:

[0139] Step 601: The first network function sends or reports fifth information to the fourth network function based on the received fourth information. The fifth information is used to indicate that address overlap occurs, triggering the fourth network function to allocate a new UE address to the terminal and perform a PDU session modification process.

[0140] In one example, the V-SMF sends or reports fifth information to the H-SMF based on the received fourth information, where the fifth information is used to indicate that address overlap occurs, triggering the H-SMF to assign a new UE address to the terminal and perform a PDU session modification process.

[0141] In some embodiments, before step 601, the method further includes the following steps: the first network function sends sixth information to the second network function, and the second network function receives the sixth information sent by the first network function, where the sixth information is used to configure the second network function to perform a first operation. Here, the first operation includes: the second network function detecting address overlap and / or detecting that DNS query information from different PDU sessions has the same source address.

[0142] In one example, the V-SMF sends sixth information to the V-UPF, where the sixth information is used to configure the second network function to perform a first operation, where the first operation includes: the V-UPF detecting address overlap, and / or the V-UPF detecting that DNS query information from different PDU sessions has the same source address.

[0143] In some embodiments, the method further includes the following steps: when the second network function detects address overlap and / or detects that DNS query information from different PDU sessions has the same source address, sending fourth information to the first network function.

[0144] In one example, when the V-UPF detects address overlap and / or detects that DNS query information from different PDU sessions has the same source address, the fourth information is sent to the V-SMF.

[0145] In some implementations, the fourth information includes at least one of the following: first indication information, a PDU session ID, and a source address, where the first indication information is used to indicate that address overlap occurs.

[0146] In some embodiments, the fifth information includes at least one of the following: second indication information, PDU session ID, source address, the second indication information is used to indicate that address overlap occurs, and / or to instruct the fourth network function to allocate a new UE address and perform a PDU session modification process.

[0147] The technical solution of the embodiment of the present disclosure proposes that the first network function (such as V-SMF) configures the second network function (such as V-UPF) to detect whether there is an address overlap event in which DNS query information from different PDU sessions has the same source address. If the second network function (such as V-UPF) detects different DNS query information from different PDU sessions but with the same source address, the second network function (such as V-UPF) will report this situation to the first network function (such as V-SMF). The first network function (such as V-SMF) will report the PDU session ID to the fourth network function (H-SMF) and indicate the UE IP address overlap, triggering the fourth network function (H-SMF) to allocate a new UE IP address and perform PDU session modification. In this way, the problem of address conflict due to cross-DNN or roaming can be avoided.

[0148] FIG7 is a second flow chart of a method for handling address overlap provided by an embodiment of the present disclosure. As shown in FIG7 , the method includes:

[0149] Step 700: The V-SMF configures the V-UPF to detect whether there is an address overlap event in which DNS query information from different PDU sessions has the same source address (referred to as: address conflict detection configuration in the figure).

[0150] Step 701: After receiving the DNS query information, the V-UPF performs address conflict detection to detect whether the received DNS query information and the stored information have the same source address as the DNS query information from different PDU sessions.

[0151] Step 702: If the V-UPF detects an address conflict, it sends address conflict information to the V-SMF. The information includes first indication information, PDU session ID, and source address. The first indication information is used to indicate that address overlap occurs.

[0152] Step 703: The V-SMF sends address conflict allocation information to the H-SMF, which includes: second indication information, PDU session ID, source address, and the second indication information is used to instruct the H-SMF to have address overlap and / or allocate a new UE IP address and perform a PDU session modification process.

[0153] Step 704: The H-SMF performs address reallocation, ie, allocates a new UE IP address.

[0154] Step 705: The H-SMF uses the newly allocated UE IP address to modify the PDU session.

[0155] FIG8 is a schematic diagram of the structure of a DNS information processing device provided in an embodiment of the present disclosure, which is applied to a first network function. As shown in FIG8 , the DNS information processing device includes:

[0156] The sending unit 801 is used to send first information to the second network function, where the first information is used to indicate that the DNS query information of the first protocol data unit PDU session needs to carry second information, and the second information is used to determine the target DNS processing rule.

[0157] In some embodiments, the apparatus further includes: a processing unit 802, configured to add the second information to at least one first DNS processing rule;

[0158] The sending unit 801 is further configured to send the obtained at least one second DNS processing rule to a third network function; wherein the target DNS processing rule is one of the at least one second DNS processing rule.

[0159] In some implementations, the apparatus further includes: a receiving unit 803, configured to receive the at least one first DNS processing rule sent by the fourth network function.

[0160] In some implementations, the fourth network function is H-SMF.

[0161] In some implementations, the third network function is V-EASDF.

[0162] In some implementations, the first network function is a V-SMF and the second network function is a V-UPF.

[0163] In some embodiments, the second information includes a DNN.

[0164] Those skilled in the art will appreciate that the functions implemented by each unit in the DNS information processing device shown in FIG8 can be understood by referring to the relevant description of the aforementioned method. The functions of each unit in the DNS information processing device shown in FIG8 can be implemented by a program running on a processor or by a specific logic circuit.

[0165] FIG9 is a second structural diagram of a DNS information processing device provided in an embodiment of the present disclosure, which is applied to a second network function. As shown in FIG9 , the DNS information processing device includes:

[0166] The receiving unit 901 is configured to receive third information sent by a terminal;

[0167] A processing unit 902 is configured to add second information to the third information based on the first information;

[0168] The sending unit 903 is configured to send the third information with the second information added thereto to a third network function; wherein the second information is used by the third network function to determine a target DNS processing rule.

[0169] In some implementations, the receiving unit 901 is further configured to receive the first information sent by the first network function, where the first information is used to indicate that the DNS query information of the first PDU session needs to carry the second information.

[0170] In some embodiments, the processing unit 902 is specifically used to determine the PDU session associated with the third information and confirm whether the PDU session is the first PDU session indicated in the first information; if it is the first PDU session indicated in the first information, detect whether the third information is DNS query information; if it is DNS query information, add the second information indicated by the first information to the third information.

[0171] In some embodiments, the first network function is a V-SMF.

[0172] In some implementations, the processing unit 902 is specifically configured to add the second information to the IP header of the third information; or add the second information to the ECSN field of the third information.

[0173] In some implementations, the second network function is a V-UPF, and the third network function is a V-EASDF.

[0174] In some embodiments, the second information includes a DNN.

[0175] Those skilled in the art will appreciate that the functions implemented by each unit in the DNS information processing device shown in FIG9 can be understood with reference to the relevant description of the aforementioned method. The functions of each unit in the DNS information processing device shown in FIG9 can be implemented by a program running on a processor or by a specific logic circuit.

[0176] FIG10 is a third structural diagram of a DNS information processing device provided in an embodiment of the present disclosure, which is applied to a third network function. As shown in FIG10 , the DNS information processing device includes:

[0177] The receiving unit 1001 is configured to receive DNS query information carrying second information sent by the second network function;

[0178] The processing unit 1002 is configured to determine a target DNS processing rule corresponding to the second information based on at least one second DNS processing rule;

[0179] The sending unit 1003 is configured to send the DNS query information to a target DNS server based on the target DNS processing rule.

[0180] In some implementations, the receiving unit 1001 is further configured to receive the at least one second DNS processing rule sent by the first network function.

[0181] In some embodiments, the first network function is a V-SMF.

[0182] In some embodiments, the receiving unit 1001 is further configured to receive DNS response information sent by the target DNS server, where the DNS response information includes a first IP address, and the first IP address corresponds to the first domain name in the DNS query information;

[0183] The sending unit 1003 is further configured to send the DNS response information to the terminal.

[0184] In some implementations, the sending unit 1003 is specifically configured to send the DNS response information to the terminal based on the second information and / or the IP address of the terminal.

[0185] In some implementations, the third network function is a V-EASDF, and the second network function is a V-UPF.

[0186] In some embodiments, the second information includes a DNN.

[0187] Those skilled in the art will appreciate that the functions implemented by each unit in the DNS information processing device shown in FIG10 can be understood by referring to the relevant description of the aforementioned method. The functions of each unit in the DNS information processing device shown in FIG10 can be implemented by a program running on a processor or by a specific logic circuit.

[0188] FIG11 is a schematic diagram of the structure of an address overlap processing device provided in an embodiment of the present disclosure, which is applied to a first network function. As shown in FIG11 , the address overlap processing device includes:

[0189] The sending unit 1101 is configured to send or report fifth information to the fourth network function based on the received fourth information, where the fifth information is used to indicate that an address overlap occurs, triggering the fourth network function to allocate a new UE address to the terminal and perform a PDU session modification process.

[0190] In some implementations, the sending unit 1101 is further configured to send sixth information to the second network function, where the sixth information is used to configure the second network function to perform the first operation.

[0191] In some embodiments, the first operation includes: the second network function detecting address overlap, and / or the second network function detecting that DNS query information from different PDU sessions has the same source address.

[0192] In some implementations, the fourth information includes at least one of the following: first indication information, a PDU session ID, and a source address, where the first indication information is used to indicate that address overlap occurs.

[0193] In some embodiments, the fifth information includes at least one of the following: second indication information, PDU session ID, source address, the second indication information is used to indicate that address overlap occurs, and / or instruct the fourth network function to allocate a new UE address and perform a PDU session modification process.

[0194] In some embodiments, the second network function is a V-UPF.

[0195] In some implementations, the first network function is a V-SMF, and the fourth network function is a H-SMF.

[0196] Those skilled in the art will appreciate that the functions implemented by each unit in the address overlap processing device shown in FIG11 can be understood by referring to the relevant description of the aforementioned method. The functions of each unit in the address overlap processing device shown in FIG11 can be implemented by a program running on a processor or by a specific logic circuit.

[0197] FIG12 is a second schematic diagram of the structure of the address overlap processing device provided in an embodiment of the present disclosure. As shown in FIG12 , the address overlap processing device includes:

[0198] The receiving unit 1201 is used to receive sixth information sent by the first network function, where the sixth information is used to configure the second network function to perform a first operation; wherein the first operation includes: the second network function detecting address overlap, and / or the second network function detecting that DNS query information from different PDU sessions has the same source address.

[0199] In some embodiments, the device further comprises:

[0200] A detecting unit 1202 is configured to detect address overlap and / or detect that DNS query information from different PDU sessions has the same source address;

[0201] The sending unit 1202 is configured to send fourth information to the first network function when address overlap is detected and / or when it is detected that DNS query information from different PDU sessions has the same source address.

[0202] In some implementations, the fourth information includes at least one of the following: first indication information, a PDU session ID, and a source address, where the first indication information is used to indicate that address overlap occurs.

[0203] In some embodiments, the first network function is a V-SMF.

[0204] In some embodiments, the second network function is a V-UPF.

[0205] Those skilled in the art will appreciate that the functions implemented by each unit in the address overlap processing apparatus shown in FIG12 can be understood by referring to the relevant description of the aforementioned method. The functions of each unit in the address overlap processing apparatus shown in FIG12 can be implemented by a program running on a processor or by a specific logic circuit.

[0206] Figure 13 is a schematic structural diagram of a communication device 1300 provided in an embodiment of the present disclosure. The communication device can be any of the network functions described above. The communication device 1300 shown in Figure 13 includes a processor 1310, which can call and run a computer program from a memory to implement the method in the embodiment of the present disclosure.

[0207] Optionally, as shown in FIG13 , the communication device 1300 may further include a memory 1320. The processor 1310 may call and execute a computer program from the memory 1320 to implement the method in the embodiment of the present disclosure.

[0208] The memory 1320 may be a separate device independent of the processor 1310 , or may be integrated into the processor 1310 .

[0209] Optionally, as shown in FIG13 , the communication device 1300 may further include a transceiver 1330 , and the processor 1310 may control the transceiver 1330 to communicate with other devices, specifically, to send information or data to other devices, or to receive information or data sent by other devices.

[0210] The transceiver 1330 may include a transmitter and a receiver. The transceiver 1330 may further include an antenna, and the number of antennas may be one or more.

[0211] The communication device 1300 may specifically be the first network function, the second network function, or the third network function of the embodiment of the present disclosure, and the communication device 1300 may implement the corresponding processes implemented by the first network function, the second network function, or the third network function in each method of the embodiment of the present disclosure. For the sake of brevity, they will not be repeated here.

[0212] Figure 14 is a schematic structural diagram of a chip according to an embodiment of the present disclosure. The chip 1400 shown in Figure 14 includes a processor 1410, which can call and run a computer program from a memory to implement the method according to the embodiment of the present disclosure.

[0213] Optionally, as shown in FIG14 , the chip 1400 may further include a memory 1420 , wherein the processor 1410 may call and execute a computer program from the memory 1420 to implement the method in the embodiment of the present disclosure.

[0214] The memory 1420 may be a separate device independent of the processor 1410 , or may be integrated into the processor 1410 .

[0215] Optionally, the chip 1400 may further include an input interface 1430. The processor 1410 may control the input interface 1430 to communicate with other devices or chips, and specifically, may obtain information or data sent by other devices or chips.

[0216] Optionally, the chip 1400 may further include an output interface 1440. The processor 1410 may control the output interface 1440 to communicate with other devices or chips, and specifically, may output information or data to other devices or chips.

[0217] The chip can be applied to the first network function, the second network function, or the third network function in the embodiment of the present disclosure, and the chip can implement the corresponding processes implemented by the first network function, the second network function, or the third network function in each method of the embodiment of the present disclosure. For the sake of brevity, they are not repeated here.

[0218] It should be understood that the chip mentioned in the embodiments of the present disclosure can also be called a system-level chip, a system chip, a chip system or a system-on-chip chip, etc.

[0219] It should be understood that the processor of the embodiments of the present disclosure may be an integrated circuit chip with signal processing capabilities. During implementation, each step of the above-mentioned method embodiment can be completed by hardware integrated logic circuits in the processor or by software instructions. The above-mentioned processor can be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. The various methods, steps, and logic block diagrams disclosed in the embodiments of the present disclosure can be implemented or executed. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the method disclosed in conjunction with the embodiments of the present disclosure can be directly implemented and executed by a hardware decoding processor, or by a combination of hardware and software modules in the decoding processor. The software module can be located in a storage medium mature in the art, such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, etc. The storage medium is located in the memory, and the processor reads the information in the memory and, in conjunction with its hardware, completes the steps of the above-mentioned method.

[0220] It is understood that the memory in the embodiments of the present disclosure may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example and not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM), and direct RAM bus random access memory (DR RAM). It should be noted that the memory of the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0221] It should be understood that the above-mentioned memories are exemplary but not restrictive. For example, the memories in the embodiments of the present disclosure may also be static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link DRAM (SLDRAM), and direct RAM RAM (DR RAM), etc. In other words, the memories in the embodiments of the present disclosure are intended to include, but are not limited to, these and any other suitable types of memories.

[0222] The present disclosure also provides a computer-readable storage medium for storing a computer program. This computer-readable storage medium can be applied to the first network function, the second network function, or the third network function in the present disclosure. The computer program causes a computer to execute the corresponding processes implemented by the first network function, the second network function, or the third network function in the various methods of the present disclosure. For the sake of brevity, these are not further described here.

[0223] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this disclosure.

[0224] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0225] In the several embodiments provided in the present disclosure, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0226] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0227] In addition, each functional unit in each embodiment of the present disclosure may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0228] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present disclosure, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present disclosure. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0229] The above description is merely a specific embodiment of the present disclosure, but the scope of protection of the present disclosure is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present disclosure should be included in the scope of protection of the present disclosure. Therefore, the scope of protection of the present disclosure should be based on the scope of protection of the claims.

Claims

1. A method for processing domain name system DNS information, the method comprising: The first network function sends first information to the second network function, where the first information is used to indicate that DNS query information of a first protocol data unit (PDU) session needs to carry second information, and the second information is used to determine a target DNS processing rule.

2. The method according to claim 1, wherein: The method further comprises: The first network function adds the second information to at least one first DNS processing rule, and sends the obtained at least one second DNS processing rule to a third network function; wherein the target DNS processing rule is one of the at least one second DNS processing rule.

3. The method according to claim 2, wherein: The method further comprises: The first network function receives the at least one first DNS processing rule sent by the fourth network function.

4. The method according to claim 3, wherein: The fourth network function is a home session management function H-SMF.

5. The method according to claim 2, wherein: The third network function is a visited-edge application service discovery function V-EASDF.

6. The method according to any one of claims 1 to 5, wherein: The first network function is a visit-session management function V-SMF, and the second network function is a visit-user plane function V-UPF.

7. The method according to any one of claims 1 to 5, wherein: The second information includes a data network name DNN.

8. A DNS information processing method, the method comprising: The second network function receives third information sent by the terminal; The second network function adds the second information to the third information based on the first information and sends the second information to the third network function; wherein the second information is used by the third network function to determine the target DNS processing rule.

9. The method according to claim 8, wherein: The method further comprises: The second network function receives the first information sent by the first network function, where the first information is used to indicate that the DNS query information of the first PDU session needs to carry the second information.

10. The method according to claim 9, wherein: The second network function adds the second information to the third information based on the first information, including: The second network function determines the PDU session associated with the third information, and confirms whether the PDU session is the first PDU session indicated in the first information; if it is the first PDU session indicated in the first information, then detects Whether the third information is DNS query information; if it is DNS query information, the second information indicated by the first information is added to the third information.

11. The method according to claim 9, wherein: The first network function is V-SMF.

12. The method according to any one of claims 8 to 11, wherein: The adding the second information to the third information comprises: Add the second information to the IP header of the third information; or, The second information is added to the domain name intelligent resolution service client subnet ECSN field of the third information.

13. The method according to any one of claims 8 to 11, wherein: The second network function is V-UPF, and the third network function is V-EASDF.

14. The method according to any one of claims 8 to 11, wherein: The second information includes a DNN.

15. A method for processing DNS information, the method comprising: The third network function receives the DNS query information carrying the second information sent by the second network function; The third network function determines a target DNS processing rule corresponding to the second information based on at least one second DNS processing rule, and sends the DNS query information to a target DNS server based on the target DNS processing rule.

16. The method according to claim 15, wherein: The method further comprises: The third network function receives the at least one second DNS processing rule sent by the first network function.

17. The method according to claim 16, wherein: The first network function is V-SMF.

18. The method according to claim 15, wherein: The method further comprises: The third network function receives the DNS response information sent by the target DNS server, where the DNS response information includes a first IP address, and the first IP address corresponds to the first domain name in the DNS query information; The third network function sends the DNS response information to the terminal.

19. The method according to claim 18, wherein: The third network function sending the DNS response information to the terminal includes: The third network function sends the DNS response information to the terminal based on the second information and / or the IP address of the terminal.

20. The method according to any one of claims 15 to 19, wherein: The third network function is V-EASDF, and the second network function is V-UPF.

21. The method according to any one of claims 15 to 19, wherein: The second information includes a DNN.

22. A method for processing address overlap, the method comprising: The first network function sends or reports fifth information to the fourth network function based on the received fourth information, where the fifth information is used to indicate that address overlap occurs, triggering the fourth network function to allocate a new UE address to the terminal and perform a PDU session modification process.

23. The method according to claim 22, wherein: The method further comprises: The first network function sends sixth information to the second network function, where the sixth information is used to configure the second network function to perform a first operation.

24. The method according to claim 23, wherein: The first operation includes: the second network function detecting address overlap, and / or the second network function detecting that DNS query information from different PDU sessions has the same source address.

25. The method according to claim 22, wherein: The fourth information includes at least one of the following: first indication information, a PDU session ID, and a source address, wherein the first indication information is used to indicate that address overlap occurs.

26. The method of claim 22, wherein: The fifth information includes at least one of the following: second indication information, PDU session ID, source address, the second indication information is used to indicate that address overlap occurs, and / or to instruct the fourth network function to allocate a new UE address and perform a PDU session modification process.

27. The method according to claim 23, wherein: The second network function is V-UPF.

28. The method according to any one of claims 22 to 27, wherein: The first network function is V-SMF, and the fourth network function is H-SMF.

29. A method for processing address overlap, the method comprising: The second network function receives the sixth information sent by the first network function, and the sixth information is used to configure the second network function to perform a first operation; wherein the first operation includes: the second network function detects address overlap, and / or the second network function detects that DNS query information from different PDU sessions has the same source address.

30. The method of claim 29, wherein: The method further comprises: When the second network function detects address overlap and / or detects that DNS query information from different PDU sessions has the same source address, fourth information is sent to the first network function.

31. The method according to claim 30, wherein: The fourth information includes at least one of the following: first indication information, a PDU session ID, and a source address, wherein the first indication information is used to indicate that address overlap occurs.

32. The method of claim 30, wherein: The first network function is V-SMF.

33. The method according to any one of claims 29 to 32, wherein: The second network function is V-UPF.

34. A DNS information processing device, applied to a first network function, the device comprising: A sending unit, configured to send first information to a second network function, wherein the first information is used to indicate a first protocol data The DNS query information of the unit PDU session needs to carry second information, and the second information is used to determine the target DNS processing rule.

35. A DNS information processing device, applied to a second network function, the device comprising: A receiving unit, configured to receive third information sent by a terminal; A processing unit, configured to add second information to the third information based on the first information; A sending unit is used to send the third information added with the second information to a third network function; wherein the second information is used by the third network function to determine a target DNS processing rule.

36. A DNS information processing device, applied to a third network function, the device comprising: A receiving unit, configured to receive DNS query information carrying second information sent by the second network function; a processing unit, configured to determine a target DNS processing rule corresponding to the second information based on at least one second DNS processing rule; A sending unit is used to send the DNS query information to a target DNS server based on the target DNS processing rule.

37. An address overlap processing device, applied to a first network function, the device comprising: A sending unit is used to send or report fifth information to a fourth network function based on the received fourth information, wherein the fifth information is used to indicate that an address overlap occurs, triggering the fourth network function to allocate a new UE address to the terminal and perform a PDU session modification process.

38. An address overlap processing device, applied to a second network function, the device comprising: A receiving unit, used to receive sixth information sent by the first network function, wherein the sixth information is used to configure the second network function to perform a first operation; wherein the first operation includes: the second network function detecting address overlap, and / or the second network function detecting that DNS query information from different PDU sessions has the same source address.

39. A communication device comprising: A processor and a memory, the memory being used to store a computer program, the processor being used to call and run the computer program stored in the memory to execute the method as claimed in any one of claims 1 to 7, or the method as claimed in any one of claims 8 to 14, or the method as claimed in any one of claims 15 to 21, or the method as claimed in any one of claims 22 to 28, or the method as claimed in any one of claims 29 to 33.

40. A chip, comprising: A processor, used to call and run a computer program from a memory so that a device equipped with the chip performs the method as described in any one of claims 1 to 7, or the method as described in any one of claims 8 to 14, or the method as described in any one of claims 15 to 21, or the method as described in any one of claims 22 to 28, or the method as described in any one of claims 29 to 33.

41. A computer-readable storage medium for storing a computer program, wherein the computer program causes a computer to perform the method as claimed in any one of claims 1 to 7, or the method as claimed in any one of claims 8 to 14, or the method as claimed in any one of claims 15 to 21, or the method as claimed in any one of claims 22 to 28, or the method as claimed in any one of claims 29 to 33.

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