Section: G.4.1 Service Registration and Service Discovery
Content: Service registration can be done in several ways. One option is that ready 5GC Service Functions may register themselves with their service profile via the Nnrf interface. The registration request is forwarded to the internal Registry as well as forwarded to the operator's NRF. The internal registration is used to store the address to identifier relationship and the Service Deployment Cluster location. The external registration (NRF) is used to expose the Service Functionality to Services outside the depicted SCP. Service discovery entails Function A requesting a resolvable identifier for Functionality B. This resolve request is received by the Service Router which performs the task with the help of the SCP. After the resolve is done, the 5GC Functionalities may communicate either directly without any further interaction through the SCP, when the targeted address is resolved within the same Service Deployment Cluster; or via the Service Router when the Functionality resides outside of the originator's Service Deployment Cluster. The Service Router then acts as gateway towards the underlying SCP platform. Figure G.4.1-1: Registering 5GC Functionalities in the SCP