Methods, systems, and computer readable media for facilitating processing of inter-public land mobile network (PLMN) messages relating to existing subscriptions

A system for facilitating processing of inter-public land mobile network (PLMN) messages relating to existing subscriptions, the system comprising:

• a first network function (NF) repository function (NRF) including at least one processor for receiving an inter-PLMN subscription creation request message for creating a subscription and determining, by the first NRF, that the first NRF includes a resource for which the subscription is requested, wherein the first NRF serves a first region in a PLMN having a plurality of regions and a second NRF serves a second region of the regions in the PLMN and the first NRF stores NF profiles of producer NFs located in the first region and registered with the NRF and the second NRF stores NF profiles of NFs located in the second region and registered with the second NRF;
• and
• a hint generator/handler implemented by the at least one processor for, 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, wherein determining that the first NRF includes a resource for which the subscription is requested includes determining that a producer NF instance identified in the subscription creation request message corresponds to one of the producer NFs located in the first region and registered with the first NRF, the hint generator/handler for including in the subscription creation response message, a hint indicating that the subscription is located on the first NRF and usable by the second NRF to forward, to the first NRF, subsequent messages related to the subscription that are received by the second NRF, and forwarding, by the first NRF, the subscription creation response message towards a consumer NF.

A non-transitory computer readable medium having stored thereon executable instructions that when executed by a processor of a computer control the computer to perform steps comprising:

• receiving, at a first network function (NF) repository function (NRF), an inter-public land mobile network (PLMN) subscription creation request message for creating a subscription, wherein the first NRF serves a first region in a PLMN having a plurality of regions and a second NRF serves a second region of the regions in the PLMN and the first NRF stores NF profiles of producer NFs located in the first region and registered with the NRF and the second NRF stores NF profiles of NFs located in the second region and registered with the second NRF;
• determining, by the first NRF, that the first NRF includes a resource for which the subscription is requested, wherein determining that the first NRF includes a resource for which the subscription is requested includes determining that a producer NF instance identified in the subscription creation request message corresponds to one of the producer NFs located in the first region and registered with the first NRF;
• 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;
• including, by the first NRF and in the subscription creation response message, a hint indicating that the subscription is located on the first NRF and usable by the second NRF to forward, to the first NRF, subsequent messages related to the subscription that are received by the second NRF;
• and
• forwarding, by the first NRF, the subscription creation response message towards a consumer NF.