Modeling NF state — sessions, contexts, subscribers

The Per-UE Context Structure

Every stateful 5GC NF maintains a per-UE or per-session context structure that holds everything it knows about that entity. For AMF the per-UE context includes: UE identifiers (SUPI, GUTI, PEI), security state (KAUSF, KAMF, NAS keys, NAS counters), serving cell and gNB identifiers, current registration state, allowed and supported network slices, list of active PDU sessions (pointers into SMF contexts), and timer state. For SMF the per-session context includes: session identifier (PDU Session ID, S-NSSAI, DNN), assigned IP address, QoS rules, UPF binding, and traffic detection rules. This…