Methods, systems, and computer-readable media for limiting hop count in a communication network

Abstract

Methods, systems, and computer-readable media for limiting hop counts made in a communication network are disclosed. One method includes receiving, by a hypertext transfer protocol (HTTP) proxy element in a first network region, a service request message including a header portion specifying a maximum hop count value and conducting a search in the first network region for a producer network function (NF) to provide a network service requested in the service request message. The method also includes determining the maximum hop count value in the header portion of the service request message if the HTTP proxy element is unable to locate the producer NF in the first network region, reducing the maximum hop count value in the header portion of the service request message by one to obtain an updated maximum hop count value if the HTTP proxy element determines that the maximum hop count value in the header portion is greater than zero, and directing the service request message containing the updated maximum hop count value to a second HTTP proxy element located in a second network region.

Description

[0001] Priority Claim

[0002] This application claims priority to U.S. Patent Application Serial No. 17 / 534,724, filed December 1, 2021, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] This document describes topics related to controlling the number of hops that service-based interface (SBI) messages can take in fifth-generation (5G) and previous-generation communication networks via Hypertext Transfer Protocol (HTTP) proxy elements. More specifically, this document describes topics related to methods, systems, and computer-readable media for limiting the number of hops in communication networks. Background Technology

[0004] In telecommunications networks, a service endpoint is an address on a network node that uniquely identifies the entity providing a service to a service consumer. A service endpoint can include an Internet Protocol (IP) address or a combination of an IP address and a transport layer port number; it is also known as an IP endpoint.

[0005] In fifth-generation (5G) telecommunications networks, network nodes that provide services are called producer network functions (NFs). Network nodes that consume services are called consumer NFs. A network function can be either a producer NF or a consumer NF, depending on whether it is consuming or providing services.

[0006] A given producer NF can have multiple service endpoints. The producer NF registers with the Network Function Repository Function (NRF). The NRF maintains NF profiles of available NF instances and their supporting services. Consumer NFs can subscribe to receive information about producer NF instances registered with the NRF. Once registered, an NF instance in a 5G network can establish a session with one or more Network Exposure Functions (NEFs). Notably, NEFs are 3GPP (3rd Generation Partnership Project) Network Functions that provide a secure means of exposing the services and capabilities offered by producer network functions that provide services to the network.

[0007] Currently, the 3GPP specification defines that service-based interface messages can traverse HTTP proxy servers based on deployment. However, there is no limit to the number of HTTP proxy servers that an SBI message (i.e., an SBI packet) can traverse in its attempt to reach the destination producer NF. While the 3GPP specification does define certain timers that can be used to define the amount of time an SBI message should take to reach the producer NF, these timer mechanisms do not limit the number of hops an SBI message can take before or after the aforementioned timers expire. Therefore, even if an SBI message has timed out, an unnecessary amount of network traffic can still be generated and / or routed.

[0008] Therefore, there is a need for improved methods and systems for limiting the number of hops in a communication network. Summary of the Invention

[0009] Methods, systems, and computer-readable media for limiting the number of hops in a communication network are disclosed. One method includes receiving a service request message including a header portion specifying a maximum hop value by a Hypertext Transfer Protocol (HTTP) proxy element in a first network area and performing a search for a producer network function (NF) in the first network area to provide the network service requested in the service request message. The method further includes determining a maximum hop value in the header portion of the service request message if the HTTP proxy element cannot locate the producer NF in the first network area; decrementing the maximum hop value in the header portion of the service request message by one to obtain an updated maximum hop value if the HTTP proxy element determines that the maximum hop value in the header portion is greater than zero; and redirecting a service request message containing the updated maximum hop value to a second HTTP proxy element located in a second network area.

[0010] According to another aspect of the methods described herein, the service request message is a service-based interface (SBI) message.

[0011] According to another aspect of the method described in this paper, the maximum hop value is initially established by the consumer NF in the service request message or via a predefined default value.

[0012] According to another aspect of the method described herein, if the maximum hop value in the header portion of the service request message is determined to be zero, the service request message is prevented from being forwarded to the second HTTP proxy element in the second network zone.

[0013] According to another aspect of the method described herein, the HTTP proxy device is a Secure Edge Protection Proxy (SEPP) or a Service Communication Proxy (SCP).

[0014] According to another aspect of the method described herein, the HTTP proxy element is configured to increase the maximum hop count in the header section or the updated maximum hop count in the header section.

[0015] According to another aspect of the method described herein, each of the first network region and the second network region is a geographically defined region.

[0016] According to another embodiment described herein, a system includes: an HTTP proxy element including at least one processor and memory, and a hop management module (HMM) implemented by the at least one processor, the hop management module being configured to receive a service request message including a header portion specifying a maximum hop value, perform a search for a producer NF in a first network area to provide the network service requested in the service request message, and determine a maximum hop value in the header portion of the service request message if the HTTP proxy element cannot locate the producer NF in the first network area. The HMM is also configured to, if the HTTP proxy element determines that the maximum hop value in the header portion is greater than zero, decrement the maximum hop value in the header portion of the service request message by one to obtain an updated maximum hop value, and redirect a service request message containing the updated maximum hop value to a second HTTP proxy device located in a second network area.

[0017] According to another aspect of the system described in this article, the service request message is a service-based interface (SBI) message.

[0018] According to another aspect of the system described in this article, the maximum hop value is initially established by the consumer NF in the service request message or via a predefined default value.

[0019] According to another aspect of the system described herein, if the maximum hop value in the header portion of the service request message is determined to be zero, the service request message is prevented from being forwarded to the second HTTP proxy element in the second network zone.

[0020] According to another aspect of the system described in this article, the HTTP proxy device is a Secure Edge Protection Proxy (SEPP) or a Service Communication Proxy (SCP).

[0021] According to another aspect of the system described herein, the HTTP proxy element is configured to increase the maximum hop value in the header section or the updated maximum hop value in the custom section.

[0022] According to another aspect of the system described herein, each of the first network region and the second network region is a geographically defined region.

[0023] The subjects described herein can be implemented in hardware, software, firmware, or any combination thereof. Therefore, the terms “function,” “node,” or “module” as used herein refer to hardware, which may also include software and / or firmware components for implementing the described features. In one example implementation, the subjects described herein may be implemented using one or more computer-readable media having computer-executable instructions stored thereon that, when executed by a computer’s processor, control the computer to perform steps. Example computer-readable media suitable for implementing the subjects described herein include non-transitory computer-readable media, such as disk storage devices, on-chip storage devices, programmable logic devices, and application-specific integrated circuits (ASICs). Furthermore, computer-readable media implementing the subjects described herein may reside on a single device or computing platform or may be distributed across multiple devices or computing platforms. Attached Figure Description

[0024] The subject matter described herein will now be explained with reference to the accompanying drawings, in which:

[0025] Figure 1 This is a network diagram illustrating an example fifth-generation (5G) network architecture;

[0026] Figure 2 This is a block diagram illustrating an example Hypertext Transfer Protocol (HTTP) proxy element for supporting skip-limit functionality of SMI messages, according to an embodiment of the subject matter described herein;

[0027] Figure 3 This is a block diagram illustrating an HTTP proxy that, under normal circumstances, forwards Service-Based Interface (SBI) messages to other HTTP proxy servers;

[0028] Figure 4 This is a block diagram illustrating an HTTP proxy of the disclosed subject, configured according to an embodiment of the subject matter described herein, capable of forwarding SBI messages to other HTTP proxy servers under specified conditions; and

[0029] Figure 5 This is a flowchart illustrating an exemplary process for limiting the number of hops in a communication network. Detailed Implementation

[0030] The subjects described herein relate to methods, systems, and computer-readable media for limiting the number of hops in a communication network. Specifically, the disclosed subjects include methods and systems for introducing a maximum hop parameter in the packet header of underlying HTTP protocol messages. In some embodiments, the disclosed subjects may utilize regular headers or custom headers to limit the number of hops transmitted between HTTP proxy devices located in multiple service areas (e.g., separate PLMNs, separate countries, separate data centers, or any other separate geographic site location). However, using custom headers with hop-limiting features (e.g., "x hops") presents a challenge because several network entities may not initially recognize or parse the custom header. For example, a Max-Forwards custom header is defined only for the TRACE and OPTIONS methods.

[0031] Reference will now be made in detail to various embodiments of the subject matter described herein, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numerals will be used throughout the drawings to refer to the same or similar parts.

[0032] Figure 1 This is a block diagram illustrating an example 5G system network architecture, such as a 5G core (5GC) network. Figure 1 The architecture includes NRF 100 and SCP 101, which can reside within the same Home Public Land Mobile Network (PLMN). As described above, NRF 100 can maintain profiles of available producer NF service instances and their supported services, and allows consumer NFs or SCPs to subscribe to and be notified of the registration of new / updated NF service instances. SCP 101 can also support service discovery and selection of NF instances. SCP 101 can perform load balancing of connections between consumer NFs and producer NFs. Furthermore, using the methods described herein, SCP 101 can perform selection and routing based on preferred NF locations.

[0033] NRF 100 is a repository of service profiles for NFs or NF instances. To communicate with an NF instance, a consumer NF or SCP must obtain an NF service profile or NF instance from NRF 100. The NF or service profile is a JavaScript Object Notation (JSON) data structure defined in 3GPP Technical Specification (TS) 29.510. The NF or service profile definition includes at least one of a Fully Qualified Domain Name (FQDN), an Internet Protocol (IP) version 4 (IPv4) address, or an IP version 6 (IPv6) address. Figure 1In this context, any node (other than NRF 100) can be either a consumer NF or a producer NF, depending on whether it is requesting or providing services. In the illustrated example, nodes include a Policy Control Function (PCF) 102 that performs policy-related operations in the network, a User Data Management (UDM) function 104 that manages user data, and an Application Function (AF) 106 that provides application services. Figure 1 The nodes illustrated also include a Session Management Function (SMF) 108 that manages the session between Access and Mobility Management Function (AMF) 110 and PCF 102. AMF 110 performs similar mobility management operations as those performed by the Mobility Management Entity (MME) in the 4G network. Authentication Server Function (AUSF) 112 performs authentication services for user equipment (UE) seeking network access, such as UE 114.

[0034] The Network Slice Selection Function (NSSF) 116 provides network slicing services for devices seeking access to specific network capabilities and characteristics associated with a network slice. The Network Exposure Function (NEF) 118 provides an application programming interface (API) for application functions seeking information about Internet of Things (IoT) devices and other UEs attached to the network. NEF 118 performs functions similar to the Service Capability Exposure Function (SCEF) in 4G networks.

[0035] Radio Access Network (RAN) 120 connects UE 114 to the network via a radio link. RAN 120 can use gNode B (gNB) (not in...) Figure 1 (As shown in the image) or other wireless access points for access. User plane function (UPF) 122 can support various proxy functionalities for user plane services. An example of such proxy functionality is Multipath Transmission Control Protocol (MPTCP) proxy functionality. UPF 122 also supports performance measurement functionality, which can be used by UE 114 to obtain network performance measurement results. Also... Figure 1 The diagram shows Data Network (DN) 124, through which the UE accesses data network services, such as Internet services.

[0036] The Security Edge Protection Agent (SEPP) 126 filters incoming traffic from another PLMN and performs topology hiding for traffic leaving the home PLMN. SEPP 126 can communicate with the SEPP in an external PLMN that manages the security of that external PLMN. Therefore, traffic between NFs in different PLMNs may traverse two SEPP functions, one for the home PLMN and the other for the external PLMN.

[0037] SEPP 126 can utilize the N32-c and N32-f interfaces. The N32-c interface is the control plane interface between two SEPPs, used to perform initial handshakes (e.g., TLS handshakes) and negotiate various parameters for N32-f interface connections and related message forwarding. The N32-f interface is the forwarding interface between two SEPPs, used to forward various communications (e.g., 5GC requests) between consumer NFs and producer NFs after application-level security protection has been applied.

[0038] Figure 2 This is a diagram illustrating example network nodes used to limit the number of hops in a communication network. For example, example HTTP proxy element 200 may represent any one or more suitable entities (e.g., one or more nodes, devices, servers, or computing platforms) for performing various aspects associated with facilitating the limitation of the number of hops transmitted SBI messages (i.e., one or more SBI packets). In some embodiments, HTTP proxy element 200 may represent or include one or more network elements, such as a Service Communication Agent (SCP) or a Secure Edge Protection Agent (SEPP). For example, HTTP proxy element 200 may represent or include an authorization server, network gateway, network proxy, edge security device, exposure function, or other functionality.

[0039] refer to Figure 2 The HTTP proxy element 200 may include one or more communication interfaces 202 for transmitting messages via a communication environment (e.g., one or more 5G networks (or 4G networks)). For example, the communication interfaces 202 may include one or more communication interfaces for communicating with various network entities, such as other HTTP proxy servers residing in the home network (e.g., Home Public Land Mobile Network (H-PLMN)), other accessed networks (e.g., Accessed Public Land Mobile Network (V-PLMN)), and / or other geographic areas.

[0040] In some embodiments, the HTTP proxy element 200 may include a hop management module (HMM) 204. The HMM 204 may be any suitable entity (e.g., software stored in memory and executed on at least one processor) for performing one or more aspects associated with managing and enforcing restrictions on the number of hops that SBI messages can be forwarded to other HTTP proxy servers.

[0041] Before describing the disclosed topics, this article presents a scenario of public network stream processing performed by an HTTP proxy server. For example, Figure 3 This is a block diagram illustrating an HTTP proxy server that forwards SBI messages to other HTTP proxy servers under normal conditions. Specifically, Figure 3 Multiple regions 301-303 interconnected via HTTP proxy servers 311-313 are depicted. In some embodiments, regions 301-303 may include geographic regions, PLMNs, or the like. Additionally, HTTP proxy servers 311-313 include SCPs, SEPs, or other similar proxy elements. In one scenario, a consumer NF 304 located in region 301 (e.g., "region A") is attempting to connect to one or more of producer NFs 310 (e.g., producer NFs 1-N) to request processing of a network service. In a scenario where the initial attempt by the consumer NF to communicate with one or more of the producer NFs 310 fails, the local HTTP proxy server 311 may need to locate a specific producer NF located in another region. For example, if consumer NF 304 is connected to the immediately adjacent HTTP proxy server 311 (e.g., SEP), the HTTP proxy server 311 will first attempt to contact the local producer NFs 310 (i.e., producer NFs 1-N) in region 301.

[0042] If these producer NFs cannot be reached (e.g., the producer NF is disabled or otherwise unavailable), HTTP proxy server 311 will attempt to communicate with the producer NFs in zone 302 via HTTP proxy server 312. Specifically, HTTP proxy 311 initially forwards SBI messages to HTTP proxy server 312, where the header of the SBI message includes a hop counter value set to '1'. Upon receiving an SBI message, HTTP proxy server 312 increments the hop counter value in the SBI message header by an increment (e.g., the hop counter is set to '1'). Figure 3 (As shown, it increases to "2"). HTTP proxy server 312 will then attempt to connect to one or more of the producer NFs 320 in local zone 302 (e.g., producer NF 1-M). If HTTP proxy server 312 cannot reach the producer NF in zone 302, the SBI message is forwarded by HTTP proxy server 312 to HTTP proxy server 313 in zone 303. Similarly, HTTP proxy server 313 will increment the hop counter value in the request message header by one when it receives the SBI message (e.g., increase the value from '2' to '3'). It is worth noting that the HTTP proxy server is currently configured to continuously forward SBI messages to other HTTP proxy servers until a producer NF that can provide service to NF consumers is located.

[0043] Specifically, there is no limit to the number of HTTP proxy servers that an SBI message can traverse. While the 3GPP specifications do define certain timers (e.g., 3GPP-SBI-Max-Rsp-Time and 3GPP-SBI-Sender-Timestamp) to help control the generation and routing of unwanted network traffic, these mechanisms only control the amount of time that request and / or response messages should arrive. Although an SBI message may actually time out while it is being processed by the first few initial HTTP proxy servers, the request may still be unnecessarily forwarded as long as the existing chain of HTTP proxy servers still exists. More specifically, this process of forwarding SBI messages to different HTTP proxy servers can continue even after the timestamp expiration measures for that message have expired.

[0044] Currently, there is no mechanism, defined by 3GPP or otherwise, to limit the number of hops after one or more timeout mechanisms have expired or passed. Therefore, such a configuration may unnecessarily generate network traffic between HTTP proxy servers when the SBI request has already timed out much earlier.

[0045] Therefore, this scenario will cause serious problems because the 3GPP-defined HTTP proxy server, which is required to attempt to identify alternative routes to the alternative producer NF, is configured to continue trying indefinitely until the HTTP proxy server chain ends or the 3GPP-SBI-Max-Rsp-Time and 3GPP-SBI-Sender-Timestamp headers fail to be validated at the HTTP proxy server (whichever is earlier).

[0046] With the advent of 5G networks, the need to make decisions faster becomes even more challenging. Figure 4 This illustrates an embodiment of the subject matter described herein, configured with an HMM (as shown above and in...). Figure 2 The diagram illustrates an HTTP proxy server (as described in the original text) that allows the HMM to forward SBI messages to other HTTP proxy servers under specified conditions. As described above, the disclosed subject includes a mechanism that utilizes packet headers at the underlying HTTP protocol to limit the number of hops for transmitting SBI messages between HTTP proxy servers located in multiple service areas (e.g., PLMNs and / or separate countries). In other embodiments, the disclosed subject may utilize custom headers to limit the number of hops transmitted between HTTP proxy servers. However, using custom headers (e.g., "x hops") can present challenges because several network entities may not be configured to recognize or parse specific custom headers.

[0047] In some embodiments, the consumer NF can specify a maximum hop count when the SBI message is generated and / or initiated. For example, the consumer NF can specify a threshold indicating the maximum hop count in the header of the SBI message. More specifically, this threshold can specify a maximum hop count that the HTTP proxy server must adhere to. Therefore, each time an SBI message arrives at an HTTP proxy server, the HTTP proxy is configured to decrease the currently specified / indicated maximum hop count by one. For example, if the maximum hop count is set to '2', then up to two HTTP proxy servers can relay the SBI message to other proxy servers. If the maximum hop count in the header portion reaches zero, the receiving HTTP proxy server will discard (i.e., stop forwarding) the SBI message. In some embodiments, the HTTP proxy server can also be configured to generate an error message indicating a timeout error or service retry. This error message can then be redirected to the original consumer NF that initiated the SBI message.

[0048] refer to Figure 4 The network administrator can specify a maximum hop count equal to "2" for SBI messages originating from consumer NF 404. For example, consumer NF 404 can set the "Maximum Hop Count" value to a certain value (e.g., "2") in the header of the SBI message by configuration or by using a fixed value. Consumer NF 404 can then initiate an SBI message and send it to HTTP proxy server 411, which is configured to locate the producer NF to provide the requested network service to consumer NF 404.

[0049] If an available producer NF 410 (e.g., one of producer NFs 1-N) is unavailable and / or cannot be identified / discovered, HTTP proxy server 411 is configured to forward the SBI message to HTTP proxy server 412 located in adjacent zone 402. Specifically, HTTP proxy server 411 (and / or HMM) is configured to first examine the header of the SBI message to determine the maximum hop value. If the maximum hop value in the header is set to '0', then HTTP proxy server 411 will discard the SBI message. However, in Figure 4 In the example shown, the maximum hop value is determined to be "2". After determining that the maximum hop value in the header of the SBI message is not equal to zero, HTTP proxy server 411 is configured to reduce the maximum hop value by one (e.g., reduce it to a value between '2' and '1'). HTTP proxy server 411 then sends the SBI message to HTTP proxy server 412. It is worth noting that intermediate HTTP proxy servers can reduce the value by "1" when forwarding the SBI message to the next entity (described below).

[0050] Upon receiving the updated SBI message, HTTP proxy server 412 is configured to locate an available producer NF in producer 420 (e.g., producer NF 1...M) within zone 402. If the producer NF cannot be found (or is unavailable) in zone 402, HTTP proxy server 412 is configured to forward the SBI message to HTTP proxy server 413 in zone 403. Notably, HTTP proxy server 412 is configured to parse / inspect the header portion of the SBI message to determine the maximum hop count. If the maximum hop count in the header is set to '0', then HTTP proxy server 412 is configured to discard the SBI message. However, in Figure 4 In the example shown, the maximum hop value is determined to be set to "1" by HTTP proxy server 412. After determining that the maximum hop value in the header of the SBI message is not equal to zero, HTTP proxy server 412 is configured to reduce the maximum hop value by one (e.g., reduce it to a value from '1' to '0'). HTTP proxy server 412 then sends the SBI message to HTTP proxy server 413 in zone 403.

[0051] After receiving the updated SBI message from HTTP proxy server 412, HTTP proxy server 413 is configured to locate an available producer NF in producer 430 (e.g., producer NF 1...K) within zone 403. If the producer NF cannot be found (or is unavailable) in zone 403, HTTP proxy server 413 is configured to forward the SBI message to another HTTP proxy server in a separate zone. Therefore, HTTP proxy server 413 is configured to parse / inspect the header portion of the SBI message to determine the maximum hop value. In this example, HTTP proxy server 413 determines that the maximum hop value in the header of the SBI message is set to '0'. In response, HTTP proxy server 413 is configured to stop the forwarding process and discard the SBI message. Additionally, HTTP proxy server 413 can be configured to send error messages and / or failure messages back to the original sending consumer NF.

[0052] In some embodiments, when a 5G proxy server, such as SCP and SEPP, attempts an alternative route in response to a failed response received from a producer NF, the maximum hop count helps reduce the number of retries and / or rerouting that an SBI message can withstand. In some embodiments, the HTTP proxy server can also be configured to modify the maximum hop count to a higher value if the HTTP proxy server deems an increase necessary for any reason.

[0053] Figure 5This is a flowchart illustrating an example process for using shared key ID and public certificate data to perform access token verification, according to embodiments of the subject matter described herein. In some embodiments, Figure 5 The method 500 described herein is an algorithm, program, or script stored in memory (e.g., such as...). Figure 2 The jump management module shown in the diagram performs the steps set forth in blocks 502-510 when executed by the processor. In some embodiments, method 500 represents a list of steps (or variations of steps) embodied in a state machine (e.g., programmed via software code or via a set of rules) and / or logic of the HTTP proxy element and / or the jump management module (HMM).

[0054] In block 502, a service request message including a header portion specifying a maximum hop count is received by an HTTP proxy element in the first network area. In some embodiments, the HTTP proxy server receives an SBI message from a consumer NF, which includes a header portion specifying a maximum hop count.

[0055] In box 504, a search for producer network functions (NFs) is performed in a first network zone to provide the network service requested in the service request message. In some embodiments, the HTTP proxy server attempts to locate the producer NF in the local zone to serve the network service requested by the consumer NF.

[0056] In box 506, if the HTTP proxy element cannot locate the producer NF in the first network area, the maximum hop count in the header portion of the service request message is determined. In some embodiments, the HTTP proxy server is unable to locate the producer NF to provide the requested service to the consumer NF. In such a scenario, the HTTP proxy server is configured to forward the service request message to another HTTP proxy server located in a second network area geographically separate from the first network area.

[0057] In box 508, if the HTTP proxy element determines that the maximum hop value in the header portion is greater than zero, it decrements the maximum hop value in the header portion of the service request message by one to obtain an updated maximum hop value. In some embodiments, the HTTP proxy server determines that the maximum hop value contained in the header portion of the service request message is greater than zero. If so, the HTTP proxy server decrements the maximum hop value in the header portion by one. If the HTTP proxy server determines that the maximum hop value contained in the header portion of the service request message is equal to zero, the HTTP proxy server discards the message and / or sends an error message to the original consumer NF that issued the service request.

[0058] In block 510, a service request message containing the updated maximum hop value is directed to a second HTTP proxy device located in a second network area. In some embodiments, the HTTP proxy server is configured to forward the service request message with the updated maximum hop value to the second HTTP proxy server in the second network area for processing.

[0059] It should be noted that the HMM and / or functionality described herein can be constructed using dedicated computing devices or facilitated by dedicated computing devices. Furthermore, the HNN and / or functionality described herein can improve the technical aspects of managing SBI-related network traffic by implementing a maximum hop count counter value in the packet header. The same implementation reduces decision time at the HTTP proxy server, resulting in improved network and resource utilization.

[0060] The publicly available information of each of the following references is incorporated into this paper in its entirety through citation.

[0061] References

[0062] 1.3rd Generation Partnership Project; Technical SpecificationGroupCore Network and Terminals; 5G System; NetworkFunction Repository Services; Stage 3(Release 17)3GPP TS

[0063] 29.510V17.3.0(2021-09)

[0064] 2.3rd Generation Partnership Project; Technical SpecificationGroupServices and System Aspects; Technical Realization ofService BasedArchitecture; Stage 3(Release 16)3GPP TS

[0065] 29.500V16.5.0(2020-11)

[0066] It will be understood that various details of the currently disclosed subject matter can be changed without departing from the scope of the currently disclosed subject matter. Furthermore, the foregoing description is for illustrative purposes only and not for limiting purposes.

Claims

1. A method for limiting the number of hops made in a communication network, the method comprising: receiving, by a hypertext transfer protocol, HTTP, proxy element in a first network region, the first network region being a first public land mobile network, PLMN, a service request message comprising a header portion specifying a maximum hop value, the service request message being a service-based interface, SBI, message; performing a search in the first network region for a producer network function, NF, to provide a network service requested in the service request message; if the HTTP proxy element is unable to locate the producer NF in the first network region, determining the maximum hop value in the header portion of the service request message; if the HTTP proxy element determines that the maximum hop value in the header portion is greater than zero, decrementing the maximum hop value in the header portion of the service request message by one to obtain an updated maximum hop value; and directing the service request message containing the updated maximum hop value to a second HTTP proxy element located in a second network region, the second network region being a second PLMN different from the first PLMN; wherein each of the HTTP proxy element and the second HTTP proxy element is a security edge protection proxy, SEPP, or a service communication proxy, SCP.

2. The method of claim 1, wherein the maximum hop value is initially established by a consumer NF in the service request message or via a pre-defined default value.

3. The method of claim 1 or 2, wherein if the maximum hop value in the header portion of the service request message is determined to be zero, the service request message is prevented from being forwarded to the second HTTP proxy element in the second network region.

4. The method of claim 1 or 2, wherein the HTTP proxy element is configured to increment the maximum hop value in the header portion or the updated maximum hop value in the header portion.

5. A system comprising: a hypertext transfer protocol, HTTP, proxy element comprising at least one processor and a memory; and a hop management module, HMM, implemented by the at least one processor, the HMM being configured for receiving, by a hypertext transfer protocol, HTTP, proxy element in a first network region, the first network region being a first public land mobile network, PLMN, a service request message comprising a header portion specifying a maximum hop value, the service request message being a service-based interface, SBI, message; performing a search in the first network region for a producer network function, NF, to provide a network service requested in the service request message; if the HTTP proxy element is unable to locate the producer NF in the first network region, determining the maximum hop value in the header portion of the service request message; if the HTTP proxy element determines that the maximum hop value in the header portion is greater than zero, decrementing the maximum hop value in the header portion of the service request message by one to obtain an updated maximum hop value; and directing the service request message containing the updated maximum hop value to a second HTTP proxy element located in a second network region, the second network region being a second PLMN different from the first PLMN; ​ ​ ​ wherein each of the HTTP proxy element and the second HTTP proxy element is a security edge protection proxy, SEPP, or a service communication proxy, SCP.

6. The system of claim 5, wherein the maximum hop count value is initially established by the consumer NF in the service request message or via a pre-defined default value.

7. The system of claim 5 or 6, wherein if the maximum hop count value in the header portion of the service request message is determined to be zero, the service request message is prevented from being forwarded to the second HTTP proxy element in the second network region.

8. The system of claim 5 or 6, wherein the HTTP proxy element is configured to increment the maximum hop count value in the header portion or the updated maximum hop count value in the header portion.

9. One or more non-transitory computer-readable media having stored thereon executable instructions that, as a result of being executed by at least one processor of a computer, cause the computer to perform the steps comprising: receiving, by a hypertext transfer protocol, HTTP, proxy element in a first network region, a service request message including a header portion specifying a maximum hop count value, the first network region being a first public land mobile network, PLMN, the service request message being a service-based interface, SBI, message; performing a search in the first network region for a producer network function, NF, to provide a network service requested in the service request message; if the HTTP proxy element is unable to locate the producer NF in the first network region, determining the maximum hop count value in the header portion of the service request message; if the HTTP proxy element determines that the maximum hop count value in the header portion is greater than zero, decrementing the maximum hop count value in the header portion of the service request message by one to obtain an updated maximum hop count value; and directing the service request message containing the updated maximum hop count value to a second HTTP proxy element located in a second network region, the second network region being a second PLMN different from the first PLMN; wherein each of the HTTP proxy element and the second HTTP proxy element is a security edge protection proxy, SEPP, or a service communication proxy, SCP.

10. The one or more non-transitory computer-readable media of claim 9, wherein the maximum hop count value is initially established by the consumer NF in the service request message or via a pre-defined default value.

11. The one or more non-transitory computer-readable media of claim 9 or 10, wherein if the maximum hop count value in the header portion of the service request message is determined to be zero, the service request message is prevented from being forwarded to the second HTTP proxy element in the second network region.

12. The one or more non-transitory computer-readable media of claim 9 or 10, wherein the HTTP proxy element is configured to increment the maximum hop count value in the header portion or the updated maximum hop count value in the header portion.

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