Added and integrated UPF graph instead of PFCP associations list
Features
- Support graph structures of UPF, e.g. N9 interfaces
- Add UPF graph edge between UPFs when NWI matches the FQDN of another UPF
- Graph is not fixed to a specific scenario
- Tested and verified with UL CL scenario (UL CL with 2 N9 interfaces)
Not supported
- PFCP procedures for the graph
- Currently, the first "exit" UPF (with N6 interface) is chosen. Thus, PDU session establishment will succeed but user plane is not successful for N9 scenarios