3GPP 23.501 v20.2.0 — the document's own text
6.3.16 SCP discovery and selection
Taught in 6. How one function finds another (The 5G system architecture, in depth).
An NF is configured with its serving SCP(s).
In a deployment where several SCPs are deployed, a message may traverse several SCP instances until reaching its final destination. A SCP may discover and select a next hop SCP by querying the Nnrf_NFDiscovery Service of the NRF or it may be configured with next SCP in the message path.
An SCP may use the SCP profile parameters in clause 6.2.6.3 as discovery parameters in Nnrf_NFDiscovery. The parameter(s) to be used depend(s) on network deployment. The NRF returns a list SCP Profiles as per the provided discovery parameters.
An SCP may consider analytics such as signalling storm analytics from the NWDAF to discover or/and select the next hop SCP.
If an SCP receives a Routing Binding Indication within a service or notification request and decides to forward that request to a next-hop SCP, it shall include the Routing Binding Indication in the forwarded request.
NOTE: It is up to SCP implementation, deployment specific configuration and operator policies as to how the SCP will use information retrieved from the NRF to resolve the optimal route to a producer.
Based on SCP configuration, an SCP deciding to address a next-hop SCP for a service request may then delegate the NF (instance) and/or service (instance) selection to subsequent SCPs and provide discovery and selection parameters to the next-hop SCP.
For the discovery of an SCP acting as NF service producer for the services listed in clause 7.2.30, the procedures in clause 6.3.1 apply.