Method, system, and program for limiting the number of hops made in a communications network

Abstract

A method, system, and computer-readable medium for limiting the number of hops performed in a communication network are disclosed. The method includes accepting, by a HyperText Transfer Protocol (HTTP) proxy element in a first network domain, a service request message including a header section specifying a maximum number of hops, and performing a search for a producer NF in the first network domain to provide the network service requested in the service request message. The method further includes determining the maximum number of hops in the header section of the service request message if the HTTP proxy element is unable to locate the producer NF in the first network domain, subtracting one from the maximum number of hops in the header section of the service request message to obtain an updated maximum number of hops if the HTTP proxy element determines that the maximum number of hops in the header section is greater than zero, and directing the service request message including the updated maximum number of hops to a second HTTP proxy element located in a second network domain.

Description

[Technical Field]

[0001] Priority claim This application claims the benefit of 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.

[0002] Technical Field The subject matter described herein relates to controlling the number of hops that service based interface (SBI) messages can take through hypertext transfer protocol (HTTP) proxy elements in fifth generation (5G) and previous generation communication networks. More particularly, the subject matter described herein relates to methods, systems, and computer-readable media for limiting the number of hops taken in a communication network. [Background technology]

[0003] background In telecommunications networks, a service endpoint is an address on a network node that uniquely identifies an entity that provides 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, referred to as an IP endpoint.

[0004] In a 5G telecommunications network, a network node that provides a service is called a producer network function (NF). A network node that consumes a service is called a consumer NF. A network function can be either a producer NF or a consumer NF depending on whether it consumes or provides a service.

[0005] A given producer NF may have many service endpoints. Producer NFs register with a network function repository function (NRF). The NRF maintains NF profiles of available NF instances and their supported services. Consumer NFs can subscribe to receive information about producer NF instances that have registered with the NRF. Once registered, NF instances in a 5G network can establish sessions with one or more network exposure functions (NEFs). Notably, the NEF is a third generation partnership project (3GPP) network function that provides a means to securely expose the services and capabilities offered by producer network functions serving the network.

[0006] To date, 3GPP specifications define that SBI messages can pass through HTTP proxy servers based on the deployment. However, there is no limit to the number of HTTP proxy servers that an SBI message (i.e., an SBI packet) can pass through when attempting to reach its destination producer NF. Although 3GPP specifications define specific timers that can be used to define the amount of time it takes for an SBI message to reach the producer NF, these timer mechanisms do not limit the number of hops taken by the SBI message before or after the expiration of said timers. As a result, unnecessary amounts of network traffic may still be generated and / or routed even though the SBI message has already expired.

[0007] Therefore, there is a need for an improved method and system for limiting the number of hops made in a communications network. Summary of the Invention

[0008] overview A method, system, and computer-readable medium are disclosed for limiting the number of hops performed in a communication network. The method includes accepting, by a HyperText Transfer Protocol (HTTP) proxy element in a first network domain, a service request message including a header section specifying a maximum number of hops, and performing a search for a producer NF in the first network domain to provide the network service requested in the service request message. The method further includes determining the maximum number of hops in the header section of the service request message if the HTTP proxy element is unable to locate the producer NF in the first network domain, subtracting one from the maximum number of hops in the header section of the service request message to obtain an updated maximum number of hops if the HTTP proxy element determines the maximum number of hops in the header section is greater than zero, and directing the service request message including the updated maximum number of hops to a second HTTP proxy element located in a second network domain.

[0009] According to another aspect of the methods described herein, the service request message is an SBI message.

[0010] According to other aspects of the methods described herein, the maximum number of hops is initially established by the consumer NF in the service request message or via a predetermined default value.

[0011] According to another aspect of the method described herein, if the maximum hop count in the header section of the service request message is determined to be 0, the service request message is prevented from being sent to a second HTTP proxy element in a second network region.

[0012] According to another aspect of the methods described herein, the HTTP proxy device may be a security edge protection proxy (SEPP), or Service Communication Proxy (service communication proxy:SCP).

[0013] According to another aspect of the methods described herein, the HTTP proxy element is configured to increase the maximum hop count of the header section or the updated maximum hop count of the header section.

[0014] According to another aspect of the methods described herein, each of the first network region and the second network region is a geographically defined region.

[0015] According to another embodiment described herein, a system includes an HTTP proxy element including at least one processor and a memory, and a hop management module (HMM) executed by the at least one processor, the hop management module being configured to accept a service request message including a header section specifying a maximum hop count, perform a search for a producer NF in a first network region to provide the network service requested in the service request message, and determine the maximum hop count in the header section of the service request message if the HTTP proxy element is unable to locate the producer NF in the first network region. The HMM further includes, if the HTTP proxy element determines the maximum hop count in the header section is greater than zero, subtracting one from the maximum hop count in the header section of the service request message to obtain an updated maximum hop count, and directing the service request message including the updated maximum hop count to a second HTTP proxy element located in a second network region.

[0016] According to another aspect of the system described herein, the service request message is an SBI message.

[0017] According to another aspect of the system described herein, the maximum number of hops is initially established by the consumer NF in the service request message or via a predetermined default value.

[0018] According to another aspect of the system described herein, if the maximum hop count in the header section of the service request message is determined to be 0, the service request message is prevented from being sent to a second HTTP proxy element in a second network region.

[0019] According to another aspect of the system described herein, the HTTP proxy device may be a Security Edge Protection Proxy (SEPP), or Service Communication Proxy (SCP).

[0020] According to another aspect of the system described herein, the HTTP proxy element is configured to increase the maximum hop count for the header section or the updated maximum hop count for the custom section.

[0021] According to another aspect of the systems described herein, each of the first network region and the second network region is a geographically defined region.

[0022] The subject matter described herein may be implemented in hardware, software, firmware, or any combination thereof. Thus, the terms “function,” “node,” or “module,” as used herein, refer to hardware for implementing the described features, but may also include software and / or firmware components. In an exemplary implementation, the subject matter described herein may be implemented using one or more computer-readable media having stored thereon computer-executable instructions that, when executed by a processor of a computer, control a computer to perform steps. Exemplary computer-readable media suitable for implementing the subject matter described herein include non-transitory computer-readable media, such as disk memory devices, chip memory devices, programmable logic devices, and application-specific integrated circuits. Additionally, computer-readable media implementing the subject matter described herein may be located on a single device or computing platform or distributed across multiple devices or computing platforms. The subject matter described herein will now be described with reference to the accompanying drawings. [Brief explanation of the drawings]

[0023] [Figure 1] FIG. 1 is a network diagram illustrating an exemplary 5G network architecture. [Figure 2] 1 is a block diagram illustrating an example HyperText Transfer Protocol (HTTP) proxy element for supporting hop limit functionality for SMI messages according to an embodiment of the subject matter described herein. [Figure 3] 1 is a block diagram illustrating an HTTP proxy that, under normal circumstances, forwards Service Based Interface (SBI) messages towards other HTTP proxy servers. [Figure 4]1 is a block diagram illustrating an HTTP proxy that can forward SBI messages to other HTTP proxy servers under specified conditions according to an embodiment of the subject matter described herein. [Figure 5] 1 is a flowchart illustrating an example process for limiting the number of hops performed in a communication network. DETAILED DESCRIPTION OF THE INVENTION

[0024] Detailed Description The subject matter described herein relates to methods, systems, and computer-readable media for limiting the number of hops performed in a communication network. More particularly, the subject matter disclosed herein includes methods and systems for introducing a max-hops parameter into the packet header of an underlying HTTP protocol message. In some embodiments, the subject matter disclosed herein can utilize either conventional or custom headers to limit the number of hops when communicating between HTTP proxy devices located in multiple service regions (e.g., separate PLMNs, separate countries, separate data centers, or other separate geographic locations). However, utilizing custom headers with hop limiting capabilities (e.g., "X-number-of-hops") can be difficult because some network entities may not initially recognize or parse the custom header. For example, the Max-Forward custom header is defined only for the TRACE and OPTIONS methods.

[0025] 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 numbers will be used throughout the drawings to refer to the same or like parts.

[0026] FIG. 1 is a block diagram illustrating an example of a 5G system network architecture, e.g., a Home 5G Core (5GC) network. The architecture of FIG. 1 includes an NRF 100 and an SCP 101, which may be located in the same home public land mobile network (PLMN). As described above, the NRF 100 maintains profiles of available producer NF service instances and their supported services, allowing consumer NFs or SCPs to subscribe to and be notified of new / updated producer NF service instances. The SCP 101 may also support service discovery and selection of NF instances. The SCP 101 may perform load balancing of connections between consumer NFs and producer NFs. Additionally, using the methods described herein, the SCP 101 may perform selection and routing based on preferred NF locations.

[0027] The NRF 100 is a repository of service profiles of NFs or NF instances. To communicate with an NF instance, a consumer NF or SCP must obtain the NF service profile or NF instance from the NRF 100. An 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 IP version 4 (IPv4) address, or an IP version 6 (IPv6) address. In FIG. 1, any node (other than the NRF 100) can be a consumer NF or a producer NF, depending on whether they are requesting or providing a service. In the illustrated example, the nodes include a policy control function (PCF) 102 that executes policy-related operations within the network, and a policy control function (PCF) 103 that manages user data. One Data Management ( unified The node shown in Figure 1 includes an access and mobility management (UDM) function 104, and an application function (AF) 106 that provides application services. The node shown in Figure 1 further includes a session management function (SMF) 108 that manages sessions between the PCF 102 and an access and mobility management (AMF) function 110. The AMF 110 performs mobility management operations similar to those performed by a mobility management entity (MME) in 4G networks. An authentication server function (AUSF) 112 performs authentication services for user devices seeking access to the network, such as user equipment (UE) 114.

[0028] The network slice selection function (NSSF) 116 provides network slice services for devices seeking to access specific network functions and features associated with the network slice. The network exposure function (NEF) 118 provides an application programming interface (API) for application functions seeking to obtain information about Internet of Things (IoT) devices and other UEs connected to the network. The NEF 118 performs a function similar to the service capability exposure function (SCEF) in 4G networks.

[0029] The radio access network (RAN) 120 connects the UE 114 to a network via a wireless link. The radio access network 120 may be accessed using a gNodeB (gNB) (not shown in FIG. 1 ) or other wireless access point. The user plane function (UPF) 122 may support various proxy functions for user plane services. One example of such a proxy function is a multipath transmission control protocol (MPTCP) proxy function. The UPF 122 may also support a performance measurement function that may be used by the UE 114 to obtain network performance measurements. Also shown in FIG. 1 is a data network (DN) 124 through which the UE accesses data network services, such as Internet services.

[0030] The Security Edge Protection Proxy (SEPP) 126 filters incoming traffic from another PLMN and performs topology hiding for traffic egressing from the home PLMN. The SEPP 126 may communicate with a SEPP in a foreign PLMN that manages security for the foreign PLMN. Thus, traffic between NFs in different PLMNs may traverse two SEPP functions: one for the home PLMN and another for the foreign PLMN.

[0031] The SEPP 126 may utilize an N32-c interface and an N32-f interface. The N32-c interface is a control plane interface between two SEPPs that can be used to perform an initial handshake (e.g., a TLS handshake) and negotiate various parameters for the N32-f interface connection and associated message transfer. The N32-f interface is a transport interface between two SEPPs that can be used to transport various communications (e.g., 5GC requests) between consumer and producer NFs after applying application-level security protections.

[0032] 2 illustrates an example of a network node for limiting the number of hops performed in a communications network. For example, the exemplary HTTP proxy element 200 represents one or more entities (e.g., one or more nodes, devices, servers, or computing platforms) suitable for implementing various aspects related to facilitating limiting the number of hops of communicated SBI messages (i.e., one or more SBI packets). In some embodiments, the HTTP proxy element 200 may represent or include one or more network elements, such as a service communication proxy (SCP) or a security edge protection proxy (SEPP). For example, the HTTP proxy element 200 may represent or include an authentication server, a network gateway, a network proxy, an edge security device, an exposure function, or other function.

[0033] 2, the HTTP proxy element 200 includes one or more communication interfaces 202 for communicating messages over a communication environment (e.g., one or more 5G or 4G networks). For example, the one or more communication interfaces 202 may include one or more communication interfaces for communicating with various network entities, such as a home network (e.g., a Home Public Land Mobile Network (H-PLMN)), other visited networks (e.g., Visited Public Land Mobile Networks (V-PLMNs)), and / or other HTTP proxy servers present in other geographic regions.

[0034] In some embodiments, HTTP proxy element 200 may include a hop management module (HMM) 204. HMM 204 may be a suitable entity (e.g., software stored in memory and executed by at least one or more processors) for performing one or more aspects related to managing and enforcing limits on the number of hops that an SBI message may be forwarded to other HTTP proxy servers.

[0035] Before describing the disclosed subject matter, a general network flow process performed by an HTTP proxy server will be described. For example, FIG. 3 is a block diagram illustrating an HTTP proxy server that forwards SBI messages to other HTTP proxy servers under normal conditions. In particular, FIG. 3 illustrates multiple regions 301-303 interconnected via HTTP proxy servers 311-313. In some embodiments, the regions 301-303 may comprise geographic regions, PLMNs, etc. Furthermore, the HTTP proxy servers 311-313 include SCPs, SEPs, or other similar proxy elements. In one example, a consumer NF 304 located in region 301 (e.g., "region A") attempts to connect to one or more producer NFs 310 (e.g., producers NF1-NFN) to request processing of a network service. If the consumer NF's first attempt to communicate with one or more producer NFs 310 fails, the local HTTP proxy server 311 may need to locate a designated producer NF located in another region. For example, when the consumer NF 304 is connected to the nearest HTTP proxy server 311 (for example, SEP), the HTTP proxy server 311 first attempts to connect to the local producer NF 310 in the area 301 (that is, the producers NF1 to N).

[0036] If it is unable to connect to these producer NFs (for example, if the producer NFs are disabled or unavailable), the HTTP proxy server 311 attempts to communicate with the producer NFs in the area 302 via the HTTP proxy server 312. Specifically, the HTTP proxy 311 first forwards an SBI message, the header of which includes a Hop-Counter value set to "1", to the HTTP proxy server 312. Upon receiving the SBI message, the HTTP proxy server 312 increments the Hop-Counter value in the SBI message header by 1 (for example, the Hop-Counter is incremented to "2" as shown in FIG. 3). Subsequently, the HTTP proxy server 312 attempts to connect to one or more producer NFs 320 (for example, NF1-M) in the local area 302. If the HTTP proxy server 312 is unable to connect to the producer NFs in the area 302, the SBI message is forwarded by the HTTP proxy server 312 to the HTTP proxy server 313 in the area 303. Similarly, upon receiving the SBI message, the HTTP proxy server 313 increments the value of the Hop-Counter in the request message header by 1 (e.g., increasing the value from "2" to "3"). Notably, the HTTP proxy server is currently configured to continuously forward the SBI message to other HTTP proxy servers until it locates a producer NF that can provide service to the NF consumer.

[0037] In particular, there is no limit to the number of HTTP proxy servers that an SBI message can pass through. Although 3GPP specifications define certain timers (e.g., 3GPP-SBI-Max-Rsp-Time and 3GPP-SBI-Sender-Timestamp) to help control the generation and routing of unnecessary network traffic, these mechanisms only control the length of time that the request and / or response messages must arrive. Although the SBI message may actually have expired while being processed by the first several initial HTTP proxy servers, the request may continue to be unnecessarily forwarded while an existing chain of HTTP proxy servers exists. More specifically, this process of forwarding the SBI message to different HTTP proxy servers can continue even after the timestamps indicate that the message has expired.

[0038] 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 lapsed, and therefore such a configuration may generate unnecessary network traffic between HTTP proxy servers even though SBI requests have long since expired.

[0039] In such cases, this situation becomes a significant problem, as 3GPP-defined HTTP proxy servers are required to identify alternative routes to alternative producer NFs and are configured to keep trying indefinitely until the chain of HTTP proxy servers is terminated or the validation of the 3GPP-SBI-Max-Rsp-Time and 3GPP-SBI-Sender-Timestamp headers at the HTTP proxy servers fails, whichever occurs first.

[0040] With the advent of 5G networks, there is an increasing need for faster decision-making. FIG. 4 is a block diagram illustrating an HTTP proxy server configured with an HMM (see above and FIG. 2) that can forward SBI messages to other HTTP proxy servers under specified conditions, in accordance with one embodiment of the subject matter described herein. As indicated above, the disclosed subject matter includes a mechanism for utilizing packet headers of the underlying HTTP protocol to limit the number of hops used to communicate SBI messages between HTTP proxy servers located in multiple service regions (e.g., PLMNs and / or separate countries). In other embodiments, the disclosed subject matter can utilize custom headers to limit the number of hops used to communicate between HTTP proxy servers. However, utilizing custom headers (e.g., "X-number-of-hops") can pose challenges because some network entities may not be configured to recognize or parse a particular custom header.

[0041] In some embodiments, a consumer NF may specify a maximum hop count when an SBI message is generated and / or initiated. For example, a threshold indicating the maximum hop count may be specified by the consumer NF in the header of the SBI message. More specifically, the threshold may specify a maximum hop count that supporting HTTP proxy servers must comply with. Thus, each time an SBI message reaches an HTTP proxy server, the HTTP proxy is configured to decrement or subtract one from the currently specified / instructed maximum hop count. For example, if the maximum hop count is set to "2," a maximum of two HTTP proxy servers may relay the SBI message to other proxy servers. If the maximum hop count in the header section becomes zero, the receiving HTTP proxy server drops the SBI message (i.e., stops forwarding). In some embodiments, the HTTP proxy server is configured to generate an error message indicating a timeout error or a service retry. The error message may then be sent to the original consumer NF that initiated the SBI message.

[0042] 4, a network administrator may specify the maximum number of hops of an SBI message originating from the consumer NF 404 as "2." For example, the consumer NF 404 may set the value of "Max-Number-of-Hops" in the header of the SBI message to a specific value (e.g., "2") by configuration or by a predetermined value. The consumer NF 404 may then initiate and send the SBI message to an HTTP proxy server 411 configured to locate a producer NF to provide the requested network service to the consumer NF 404.

[0043] If an available producer NF410 (e.g., one of producers NF1-N) is unavailable and / or cannot be identified / discovered, the HTTP proxy server 411 is configured to forward the SBI message to an HTTP proxy server 412 located in an adjacent region 402. Specifically, the HTTP proxy server 411 (and / or the HMM) is configured to first inspect the header of the SBI message to determine the value of Max-Number-of-Hops. If the value of Max-Number-of-Hops in the header is set to "0", the HTTP proxy server 411 drops the SBI message. However, in the example shown in FIG. 4, the value of Max-Number-of-Hops is determined to be "2". After determining that the value of Max-Number-of-Hops in the header of the SBI message is not zero, the HTTP proxy server 411 is configured to decrement the value of Max-Number-of-Hops by one (e.g., decrement the value from "2" to "1"). The HTTP proxy server 411 then transmits the SBI message to the HTTP proxy server 412. Notably, an intermediate HTTP proxy server may decrement the value by "1" when forwarding the SBI message to the next entity (as described below).

[0044] After receiving the updated SBI message, the HTTP proxy server 412 is configured to locate an available producer NF from among the producer NFs 420 (e.g., producers NF1-M) in the region 402. If no producer NF is found (or available) in the region 402, the HTTP proxy server 412 is configured to forward the SBI message to the HTTP proxy server 413 in the region 403. In particular, the HTTP proxy server 412 is configured to parse / inspect the header section of the SBI message to determine the value of Max-Number-of-Hops. If the value of Max-Number-of-Hops in the header is set to "0", the HTTP proxy server 412 is configured to drop the SBI message. However, in the example shown in FIG. 4 , the value of Max-Number-of-Hops is determined to be set to "1" by the HTTP proxy server 412. After determining that the value of Max-Number-of-Hops in the header of the SBI message is not zero, the HTTP proxy server 412 is configured to decrement the value of Max-Number-of-Hops by 1 (e.g., decrement the value from "1" to "0"). HTTP proxy server 412 then sends the SBI message to HTTP proxy server 413 in region 403 .

[0045] After receiving the updated SBI message from the HTTP proxy server 412, the HTTP proxy server 413 is configured to locate an available producer NF from among the producer NFs 430 (e.g., producers NF1-K) in the region 403. If no producer NF is found (or available) in the region 403, the HTTP proxy server 413 is configured to forward the SBI message to yet another HTTP proxy server in another region. As such, the HTTP proxy server 413 is configured to parse / inspect the header section of the SBI message to determine the value of Max-Number-of-Hops. In this example, the HTTP proxy server 413 determines that the value of Max-Number-of-Hops in the header of the SBI message is set to "0." In response, the HTTP proxy server 413 is configured to abort the forwarding process and drop the SBI message. The HTTP proxy server 413 may further be configured to send an error message and / or fail the message back to the original sending consumer NF.

[0046] In some embodiments, the Max-Number-of-Hops count helps reduce the number of retries and reroutes that an SBI message can undergo when 5G proxy servers, such as SCPs and SEPPs, are attempting to substitute routing in response to receiving a failure response from a producer NF. In some embodiments, the HTTP proxy server may be configured to modify the value of Max-Number-of-Hops to a higher value if the HTTP proxy server deems an increase justified for any reason.

[0047] 5 is a flowchart illustrating an exemplary process for sharing key ID and public certificate data for access token validation, according to one embodiment of the subject matter described herein. In some embodiments, process 500 shown in FIG. 5 is an algorithm, program, or script stored in memory (e.g., a hop management module as shown in FIG. 2) that, when executed by a processor, performs the steps set forth in steps 502-510. In some embodiments, method 500 represents a list of steps (or variations of steps) embodied in a state machine (e.g., via software code programming or via a set of rules) and / or logic of an HTTP proxy element and / or a hop management module (HMM).

[0048] In step 502, a service request message including a header section specifying a value for the maximum number of hops is received by an HTTP proxy element in a first network domain. In some embodiments, the HTTP proxy server receives an SBI message from a consumer NF including a header section specifying a value for the maximum number of hops.

[0049] In step 504, a producer network function (NF) is searched for in the first network domain to provide the network service requested in the service request message. In some embodiments, the HTTP proxy server attempts to locate a producer NF in the local domain to provide the requested network service of the consumer NF.

[0050] In step 506, if the HTTP proxy element is unable to locate the producer NF in the first network region, it determines a value for the maximum hop count in the header section of the service request message. 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 case, the HTTP proxy server is configured to forward the service request message to another HTTP proxy server located in a second network region that is geographically separated from the first network region.

[0051] In step 508, if the HTTP proxy element determines that the value of the maximum hop count in the header section is greater than zero, it decrements the value of the maximum hop count in the header section of the service request message by one to obtain an updated maximum hop count value. In some embodiments, the HTTP proxy server determines that the value of the maximum hop count included in the header section of the service request message is greater than zero. In such a case, the HTTP proxy server decrements the value of the maximum hop count in the header section by one. If the HTTP proxy server determines that the value of the maximum hop count included in the header section of the service request message is zero, the HTTP proxy server drops the message and / or sends an error message to the original consumer NF that made the service request.

[0052] The service request message including the updated maximum number of hops is directed to a second HTTP proxy device located in the second network region, step 510. In some embodiments, the HTTP proxy server is configured to forward the service request message including the updated maximum number of hops to the second HTTP proxy server in the second network region for processing.

[0053] It should be noted that the HMM and / or functionality described herein may constitute or be facilitated by a special-purpose computing device. Additionally, the HNN and / or functionality described herein may improve the art of managing SBI-related network traffic by implementing a maximum hop count counter value in packet headers. Implementing the same may reduce decision-making time in HTTP proxy servers, thereby improving network and resource utilization.

[0054] The disclosure of each of the following documents is incorporated herein by reference in its entirety:

[0055] References 1. 3rd Generation Partnership Project; Technical Specification Group Core Network and Terminals; 5G System; Network Function Repository Services; Stage 3 (Release 17) 3GPP TS 29.510 V17.3.0 (2021-09) 2. 3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; Technical Realization of Service Based Architecture; Stage 3 (Release 16) 3GPP TS 29.500 V16.5.0 (2020-11) It will be understood that various details of the presently disclosed subject matter may be changed without departing from the scope of the presently disclosed subject matter. Further, the foregoing description is for purposes of illustration only, and not limitation.

Claims

1. 1. A method for limiting the number of hops made in a communications network, comprising: receiving, by a HyperText Transfer Protocol (HTTP) proxy element in the first network region, a service request message including a header section specifying a maximum number of hops; performing a search for producer NFs in the first network domain for providing the network service requested in the service request message; determining a maximum value for the number of hops in the header section of the service request message if the HTTP proxy element is unable to locate the producer NF in the first network region; if the HTTP proxy element determines that the maximum hop count value in the header section is greater than 0, subtracting 1 from the maximum hop count value in the header section of the service request message to obtain an updated maximum hop count value; directing the service request message including the updated maximum number of hops to a second HTTP proxy element located in a second network region; The method, wherein the HTTP proxy element is a security edge protection proxy (SEPP) or a service communication proxy (SCP).

2. The method of claim 1 , wherein the service request message is an SBI message.

3. The method of claim 1 or 2, wherein the maximum number of hops is initially established by a consumer NF in the service request message or via a predetermined default value.

4. 3. The method of claim 1, wherein if the maximum hop count value in the header section of the service request message is determined to be 0, the service request message is prevented from being sent to the second HTTP proxy element in the second network region.

5. The method of claim 1 or 2, wherein each of the first network region and the second network region is a geographically defined region.

6. a HyperText Transfer Protocol (HTTP) proxy element including at least one processor and a memory; a Hop Management Module (HMM) executed by the at least one processor; The hop management module: receiving, by an HTTP proxy element in the first network region, a service request message including a header section specifying a maximum number of hops; performing a search for a producer NF in the first network domain to provide the network service requested in the service request message; determining a maximum value for the number of hops in the header section of the service request message if the HTTP proxy element is unable to locate the producer NF in the first network region; if the HTTP proxy element determines that the maximum hop count value in the header section is greater than 0, subtracting 1 from the maximum hop count value in the header section of the service request message to obtain an updated maximum hop count value; directing the service request message including the updated maximum number of hops to a second HTTP proxy element located in a second network region; The system, wherein the HTTP proxy element is a security edge protection proxy (SEPP) or a service communication proxy (SCP).

7. The system of claim 6 , wherein the service request message is an SBI message.

8. The system according to claim 6 or 7, wherein the maximum number of hops is initially established by a consumer NF in the service request message or via a predetermined default value.

9. 8. The system of claim 6, wherein if the maximum hop count value in the header section of the service request message is determined to be 0, the service request message is prevented from being sent to the second HTTP proxy element in the second network region.

10. 8. The system according to claim 6, wherein each of the first network region and the second network region is a geographically defined region.

11. A program for causing a computer to execute the method according to claim 1 or 2.

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