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PCAP Lab advanced 30 min4 graded questions
N2 (Inter-AMF) Handover Failure — What Went Wrong?
A UE crossing a TA boundary between two AMF sets gets stuck mid-handover. Source and target AMFs exchange Namf_Communication on N14, UDM is queried, and something comes back empty. Find the root-cause packet and decide what the NOC has to change.
Scenario
A UE is moving between two different TAs (Tracking Areas) served by different AMFs. The source AMF (10.45.0.1, metropolitan region) and target AMF (10.45.0.2, suburb region) are in different AMF sets. The UE has one active PDU session (id=3, S-NSSAI 01-000000, DNN `internet`).
The handover fails mid-procedure. You have the N2 trace (source gNB ↔ source AMF ↔ target AMF ↔ target gNB via N14) and the Nsmf/Nudm traffic. The UE eventually loses radio on the source cell and its PDU session is torn down.
Your job: walk through the N2 handover procedure (TS 23.502 §4.9), identify the first packet that shows the real problem (not the symptoms), and decide whether this is fixable in UDM subscription data, in AMF configuration, or somewhere else entirely. Pay special attention to the Namf_Communication (TS 29.518) exchange between the two AMFs — the story is there.
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