Fault Handling: IMSI unknown in HLR(#2) for PS attach

Symptom:

The SGSN sends a reject message to the MS and the cause value is #2.

Fault Analysis:

If the IMSI is unknown, enable the signaling trace function and you can view that the response message from the HLR is UNKNOWN_SUBSCRIBER (MAP cause value #1).

Cause Analysis:

The IMSI is not subscribed to the HLR or the subscription is incorrect.