Selection of a security edge protection proxy

1 . An apparatus comprising:

at least one processor; and

at least one memory storing instructions of a network repository function (NRF) of a communication network, wherein the instructions, when executed by the at least one processor, cause the apparatus to perform operations, the operation comprising at least:

receiving from each representive security edge proxty (SEPP) a plurality of security edge protection proxy (SEPPs), a respective registration message, wherein the respective registration message received from a respective SEPP of the plurality of SEPP comprises a request to register the respective SEPP with the NRF, and wherein the respective registration message comprises:

one or more identities of one or more remote mobile networks that the respective SEPP is connected to, wherein a respective identity of the one or more identities identifies a respective remote mobile network of the one or more remote mobile networks that the respective SEPP is connected to, wherein a respective remote mobile network comprises a remote public land mobile network (PLMN) that the respective SEPP is connected to or a remote stand-alone non-public network (SNPN) that the respective SEPP is connected to; and

at least one agreed interface purpose per remote mobile network of the one or more remote mobile networks that the respective SEPP is connected to, wherein each respective agreed interface purpose of the at least one agreed interface purpose per remote mobile network comprises a purpose of intended usage of a connection of the respective SEPP over an inter-network interface;

registering the plurality of SEPPs by storing information about plurality of SEPP, wherein the information about the plurality of SEPPS comprises for each respective SEPP of the plurality of SEPPS, information about the respective SEPP that includes the one or more identities of the one or more remote mobile networks that the respective SEPP is connected to and the at least one agreed interface purpose per remote mobile network of the one or more remote networks that the respective SEPP is connected to;

receiving a discovery request for discovery of at least one SEPP of the plurality of SEPPs, the discovery request comprising an identity of target remote mobile network and at least one agreed interface purpose for the target remote network, wherein the target remote network is a target PLMN or a target SNPN;

selecting, from among the plurality of SEPP, the at least one SEPP of the plurality of SEPPs based on the information about the plurality of SEPPs, the identity of target remote mobile network included in the discovery request, and the at least one agreed interface purpose for the target remote network included in the discovery request, wherein the selecting comprises:

for each respective SEPP of the plurality of SEPPs:

determining whether the identity of the target mobile network matches the identity of a remote mobile network of the one or more remote mobile networks that the respective SEPP is connected to;

based on determining that the identity of the target mobile network matches the identity of a remote mobile network of the one or more remote mobile networks that the respective SEPP is connected to, determining whether the at least one agreed interface purpose for the target remote mobile network matches an interface purpose of the at least one agreed interface purpose for the remote mobile network; and

based on determining that the at least one agreed interface purpose for the target remote mobile network matches the interface purpose of the at least one agreed interface purpose for the remote mobile network, selecting the respective SEPP; and

transmitting, a response to the discovery request, the response comprising the information about each respective SEPP that is selected.

2 . The apparatus of claim 1 , wherein the operations further comprise:

receiving a subscription for notification of changes to the information about the least one SEPP.

3 . The apparatus of claim 2 , wherein the operations further comprise:

receiving, from the at least one SEPP, an indication of an update to at least one of the at least one agreed interface purpose per remote mobile network that the at least one SEPP is connected to; and

transmitting a notification of the change to the information about the at least one SEPP.

4 . The apparatus of claim 2 , wherein the operations further comprise:

receiving, from a SEPP of the plurality of SEPP other than the at least one SEPP that is selected, an indication of an update to at least one of the at least one agreed interface purpose per remote mobile network that the SEPP is connected to; and

transmitting a notification of the change to the information about the SEPP.

5 . The apparatus of claim 3 , wherein the operations further comprise:

receiving, from a SEPP of the plurality of SEPP other than the at least one SEPP that is selected, an indication of a change to the at least one remote mobile network that the SEPP is connected to; and

transmitting a notification of the change to the information about the SEPP.

6 . The apparatus of claim 1 , wherein

the discovery request is received from a network function consumer or a service communication proxy associated with the network function consumer.

7 . The apparatus of claim 1 ,

wherein the at least one agreed interface purpose per remote mobile network that the at least one SEPP is connected to comprises at least one of: roaming, inter-PLMN mobility, roaming testing, inter-PLMN mobility testing, inter-PLMN signalling, short message service, or interconnect.

8 . A method comprising:

receiving from each respective security edge proxy (SEPP) of a plurality of security edge protection proxy (SEPPs), a respective registration message, wherein the respective registration message received from a respective SEPP of the plurality of SEPP comprises a request to register the respective SEPP with the NRF, and wherein the respective registration message comprises:

one or more identities of one or more remote mobile networks that the respective SEPP is connected to, wherein a respective identity of the one or more identities identifies a respective remote mobile network of the one remote mobile network that the respective SEPP is connected to, wherein a respective remote mobile network comprises a remote public land mobile network (PLMN) that the respective SEPP is connected to or a remote stand-alone non-public network (SNPN) that the respective SEPP is connected to; and

at least one agreed interface purpose per remote mobile network of the one or more remote mobile network that the respective SEPP is connected to, wherein each respective agreed interface purpose of the at least one agreed interface purpose per remote mobile network comprises a purpose of intended usage of a connection of the respective SEPP over an inter-network interface;

registering the plurality of SEPPs by storing information about the plurality of SEPP, wherein the information about the plurality of SEPPs includes information about each respective SEPP of the plurality of SEPPs, wherein the information about a respective SEPP includes information about the respective SEPP that includes the one or more identities of the one or more remote mobile networks that the respective SEPP is connected to and the at least one agreed interface purpose per remote mobile network of the one or more remote networks that the respective SEPP is connected to;

receiving a discovery request for discovery of at least one SEPP of the plurality of SEPPs, the discovery request comprising an identity of target remote mobile network and at least one agreed interface purpose for the target remote network, wherein the target remote network is a target PLMN or a target SNPN;

selecting, from among the plurality of SEPP, the at least one SEPP of the plurality of SEPPs based on the information about the plurality of SEPPs the identity of the target mobile network included in the discovery, and the at least one agreed interface purpose for the target remote network included in the discovery request, wherein the selecting comprises:

for each respective SEPP of the plurality of SEPPs:

determining whether the identity of the target mobile network matches the identity of a remote mobile network of the one or more remote mobile networks that the respective SEPP is connected to;

based on determining that the identity of the target mobile network matches the identity of a remote mobile network of the one or more remote mobile networks that the respective SEPP is connected to, determining whether the at least one agreed interface purpose for the target remote mobile network matches an interface purpose of the at least one agreed interface purpose for the remote mobile network; and

based on determining that the at least one agreed interface purpose for the target remote mobile network matches the interface purpose of the at least one agreed interface purpose for the remote mobile network, selecting the respective SEPP; and

transmitting, a response to the discovery request, the response comprising the information about each respective SEPP that is selected.

9 . The method of claim 8 , further comprising:

receiving a subscription for notification of changes to the information about the least one SEPP.

10 . The method of claim 9 , further comprising:

receiving, from the at least one SEPP, an indication of an update to at least one of the at least one agreed interface purpose per remote mobile network that the at least one SEPP is connected to; and

transmitting a notification of the change to the information about the at least one SEPP.

11 . The method of claim 9 , further comprising:

receiving, from a SEPP of the plurality of SEPP other than the at least one SEPP that is selected, an indication of an update to at least one of the at least one agreed interface purpose per remote mobile network that the SEPP is connected to; and

transmitting a notification of the change to the information about the SEPP.

12 . The method of claim 9 , wherein the operations further comprise:

receiving, from a SEPP of the plurality of SEPP other than the at least one SEPP that is selected, an indication of a change to the at least one remote mobile network that the SEPP is connected to; and

transmitting a notification of the change to the information about the SEPP.

13 . The method of claim 11 , wherein the operations further comprise:

receiving, from a SEPP of the plurality of SEPP other than the at least one SEPP that is selected, an indication of a change to the at least one remote mobile network that the SEPP is connected to; and

transmitting a notification of the change to the information about the SEPP.

14 . The method of claim 8 , wherein the discovery request is received from a network function consumer or a service communication proxy associated with the network function consumer.

15 . The method of claim 8 , wherein the at least one agreed interface purpose per remote mobile network of the at least one mobile network that the respective SEPP is connected to comprises at least one of: roaming, inter-PLMN mobility, roaming testing, inter-PLMN mobility testing, inter-PLMN signalling, short message service, or interconnect.