Abstract: Methods, systems, and computer readable media for validating subscriber entities against spoofing attacks in a communications network are disclosed. One method includes receiving, by a proxy element, a subscriber authentication request message that is sent from an access and mobility management function (AMF) and is directed to a unified data management (UDM) function in a home network, creating, by the proxy element, a record entry including a subscriber identifier and a public land mobile network (PLMN) identifier contained in the subscriber authentication request message, wherein the record entry is stored in an authentication registry database prior to forwarding the subscriber authentication request message to the UDM function.

Abstract: A method for processing NF discovery requests using prioritized lists of preferred locations includes maintaining an NF profiles database including NF profiles of producer NFs registered to provide service to other NFs and a preferred locality attribute mappings database including mappings between preferred locality attributes and prioritized lists of preferred locations. The method includes receiving, from an NF, an NF discovery request including query parameters and a preferred locality attribute. The method further includes accessing the preferred locality attribute mappings database using the preferred locality attribute and obtaining a prioritized list of preferred locations corresponding to the preferred locality attribute, accessing the NF profiles database using the query parameters and identifying NF profiles of producer NFs capable of providing a service indicated by the query parameters, and prioritizing the NF profiles according to the prioritized list of preferred locations.

Abstract: Methods, systems, and computer readable media for enabling forwarding of subsequent network function subscription updates. A method includes forwarding, from a bootstrapped network function repository function (NRF) in a first region, a subscription creation request from a consumer network function to a target NRF in a second region. The method includes creating, at the target NRF, a subscription for the consumer network function. The method includes generating, at the target NRF, a hint comprising data indicating one or more alternate NRFs each sharing subscription state data with the target NRF. The method includes sending, from the target NRF to the consumer network function, a subscription response message including the hint.

Abstract: A method for providing updated network slice information to a network slice selection function (NSSF includes registering, by a network slice management function (NSMF) with a network function (NF) repository function (NRF), an NF profile corresponding to the NSMF and subscribing, by the NSMF with the NRF, for status updates corresponding to NF instances belonging to network slice instances created by the NSMF. The method further includes receiving, by the NSMF from the NRF, a notification message including one or more network traffic load level updates related to at least one of the NF instances, processing the one or more network traffic load level updates to generate network slice instance configuration information for at least one of the network slice instances, and providing, by the NSMF, the network slice instance configuration information to a NSSF managing the at least one of the network slice instances.

Abstract: A method for avoiding sending duplicate notifications for overlapping subscriptions includes, at a network function (NF) repository function (NRF), detecting an event relating to an NF. The method further includes identifying a plurality of subscriptions having a subscription condition corresponding to the event. The method further includes generating a list of the plurality of subscriptions having a subscription condition corresponding to the event. The method further includes iterating through the list of subscriptions and identifying overlapping subscriptions. The method further includes removing the overlapping subscriptions from the list. The method further includes sending notification messages to NFs corresponding to subscriptions remaining in the list.

Abstract: A method for applying or overriding preferred locality criteria in processing NF discovery requests includes, at an NRF including at least one processor, maintaining an NF profiles database including NF profiles of producer NFs registered to provide service to other NFs, receiving, from an NF, an NFDiscover request including a preferred-locality attribute or lacking a preferred-locality attribute, accessing the NF profiles database to identify NF profiles of producer NFs capable of providing a service indicated by query parameters in the NFDiscover request, generating an NFDiscover response including the NF profiles identified as capable of providing the service indicated by the query parameters in the NFDiscover request, prioritizing the NF profiles in the NFDiscover response in a manner that overrides the preferred-locality attribute in the NFDiscover request or applies a preferred locality attribute selected by the NRF, and transmitting the NFDiscover response to the NF that transmitted the NFDiscover requ

Abstract: Methods, systems, and computer readable media for managing network function (NF) request messages at a security edge protection proxy (SEPP) are disclosed. One method comprises receiving, by a SEPP and from an NF service consumer, an initial NF request message and obtaining a target NF type identifier, a requestor NF type identifier, and a network identifier from the initial NF request message. The method further includes utilizing the target NF type identifier, the requestor NF type identifier, and the network identifier to determine whether the initial NF request message is to be blocked by an associated service based interface at the SEPP and discarding, by the SEPP, the initial NF request message if the initial NF request message is determined to be blocked by the associated service based interface.

Abstract: A method for facilitating processing of inter-public land mobile network (PLMN) messages relating to existing subscriptions includes receiving, at a first network function (NF) repository function (NRF), an inter-PLMN subscription creation request message for creating a subscription. The method further includes determining, by the first NRF, that the first NRF includes a resource for which the subscription is requested. The method further includes, in response to determining that the first NRF includes a resource for which the subscription is requested, generating, by the first NRF, a subscription creation response message indicating creation of the subscription. The first NRF includes, in the subscription creation response message, a hint indicating that the subscription is located on the first NRF and forwards the first NRF, the subscription creation response message towards a consumer NF.

Abstract: Methods, systems, and computer readable media for limiting network function (NF) repository function (NRF) forwarding are disclosed. One example method for limiting NRF forwarding comprises: at a first NF comprising at least one processor: receiving a request message associated with a consumer NF; determining that the request message cannot be serviced by the first NF; inserting or modifying a forwarding limit value in the request message, wherein the forwarding limit value indicates a number of times that the request message can be forwarded; and forwarding the request message including the forwarding limit value toward a second NF.

Abstract: Methods, systems, and computer readable media for discovering network function (NF) service producers in a hierarchical network are disclosed. One method includes receiving, by a regional NF repository function (NRF) operating in a first region of a hierarchical network, a NF registration request message from a NF service producer operating in the first region and detecting, by the regional NRF, an absence of <NF-Type>Info and/or <NF-Type>InfoList attribute data in the received NF registration request message.

Abstract: Methods, systems, and computer readable media for utilizing network function (NF) service attributes associated with registered network function service producers in a hierarchical network are disclosed. One method comprises receiving, by a root network function repository function (NRF) operating in a hierarchical network and from a regional NRF operating in a first region of the hierarchical network, a NF registration message or a NF update message, wherein the NF registration message or NF update message includes an NrfInfo structure that contains one or more NF service attributes specifying one or more NF services provided by at least one NF service producer registered with the regional NRF. The method further includes extracting, by the root NRF, the one or more NF service attributes from the NrfInfo structure, and creating, by the root NRF, one or more indexed entries containing the one or more NF service attributes in a local state information database.

Abstract: Methods, systems, and computer readable media for validating subscriber entities against spoofing attacks in a communications network are disclosed. One method includes receiving, by a proxy element, a subscriber authentication request message that is sent from an access and mobility management function (AMF) and is directed to a user data management (UDM) function in a home network, creating, by the proxy element, a record entry including a subscriber identifier and a public land mobile network (PLMN) identifier contained in the subscriber authentication request message, wherein the record entry is stored in an authentication registry database prior to forwarding the subscriber authentication request message to the UDM function.

Abstract: Methods, systems, and computer readable media for enabling forwarding of subsequent network function subscription updates. A method includes forwarding, from a bootstrapped network function repository function (NRF) in a first region, a subscription creation request from a consumer network function to a target NRF in a second region. The method includes creating, at the target NRF, a subscription for the consumer network function. The method includes generating, at the target NRF, a hint comprising data indicating one or more alternate NRFs each sharing subscription state data with the target NRF. The method includes sending, from the target NRF to the consumer network function, a subscription response message including the hint.

Abstract: Methods, systems, and computer readable media for restricting a number of hops conducted in a communications 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 section that specifies a maximum number of hops value and conducting a search for a producer network function (NF) in the first network region to provide a network service requested in the service request message.

Abstract: A method for dynamically updating domain name system (DNS) records from network function (NF) profile information includes, at an NF repository function (NRF) including at least one processor, receiving a message relating to an NF profile of an NF. The method further includes constructing, based on NF service availability information in the NF profile and local configuration of the NRF, a DNS resource record for the NF. The method further includes utilizing a dynamic DNS update procedure to dynamically update a DNS resource record for the NF with a DNS server.

Abstract: Methods, systems, and computer readable media for limiting network function (NF) repository function (NRF) forwarding are disclosed. One example method for limiting NRF forwarding comprises: at a first NF comprising at least one processor: receiving a request message associated with a consumer NF; determining that the request message cannot be serviced by the first NF; inserting or modifying a forwarding limit value in the request message, wherein the forwarding limit value indicates a number of times that the request message can be forwarded; and forwarding the request message including the forwarding limit value toward a second NF.

Abstract: A method for processing NF discovery requests using prioritized lists of preferred locations includes maintaining an NF profiles database including NF profiles of producer NFs registered to provide service to other NFs and a preferred locality attribute mappings database including mappings between preferred locality attributes and prioritized lists of preferred locations. The method includes receiving, from an NF, an NF discovery request including query parameters and a preferred locality attribute. The method further includes accessing the preferred locality attribute mappings database using the preferred locality attribute and obtaining a prioritized list of preferred locations corresponding to the preferred locality attribute, accessing the NF profiles database using the query parameters and identifying NF profiles of producer NFs capable of providing a service indicated by the query parameters, and prioritizing the NF profiles according to the prioritized list of preferred locations.

Abstract: A method for distributing connections to mobility management node instances includes publishing IP addresses for receiving connection requests and ingress messages from RAN nodes. The method further includes maintaining connection loading measurements of the mobility management node instances, receiving a connection request message generated by a RAN node for initiating a connection with one of the mobility management node instances, applying a connection distribution algorithm to select a mobility management node instance to handle the connection request message, and creating an association between an IP address of the selected mobility management node instance and an IP address and port of the RAN node extracted from a source IP address and source port field of the connection request. The method further includes forwarding the connection request message to the selected mobility management node instance.

Abstract: A method for providing updated network slice information to a network slice selection function (NSSF includes registering, by a network slice management function (NSMF) with a network function (NF) repository function (NRF), an NF profile corresponding to the NSMF and subscribing, by the NSMF with the NRF, for status updates corresponding to NF instances belonging to network slice instances created by the NSMF. The method further includes receiving, by the NSMF from the NRF, a notification message including one or more network traffic load level updates related to at least one of the NF instances, processing the one or more network traffic load level updates to generate network slice instance configuration information for at least one of the network slice instances, and providing, by the NSMF, the network slice instance configuration information to a NSSF managing the at least one of the network slice instances.

Abstract: A method for applying or overriding preferred locality criteria in processing NF discovery requests includes, at an NRF including at least one processor, maintaining an NF profiles database including NF profiles of producer NFs registered to provide service to other NFs, receiving, from an NF, an NFDiscover request including a preferred-locality attribute or lacking a preferred-locality attribute, accessing the NF profiles database to identify NF profiles of producer NFs capable of providing a service indicated by query parameters in the NFDiscover request, generating an NFDiscover response including the NF profiles identified as capable of providing the service indicated by the query parameters in the NFDiscover request, prioritizing the NF profiles in the NFDiscover response in a manner that overrides the preferred-locality attribute in the NFDiscover request or applies a preferred locality attribute selected by the NRF, and transmitting the NFDiscover response to the NF that transmitted the NFDiscover requ