Persistence — Redis, etcd, PostgreSQL for NF state

Three Tiers of NF State

Production 5GC implementations classify state into three tiers based on access pattern, durability needs, and consistency requirements. Hot transient state — per-UE registration context, per-session SMF binding, in-flight authentication challenges — needs sub-millisecond access at high concurrency. Redis or Hazelcast in-memory grids are the right fit; data is replicated across a few nodes for resilience but loss is acceptable on a major outage because it can be re-established by UE re-registration. Durable subscriber state — UDM subscription profiles, billing records — must survive any…