Attach Failure Scenario 4 (Improper SS7 Data Configuration)

selim.hasan
selim.hasan  Diamond  (1)
5 years 8 months ago  View: 870  Reply: 0
lLocating an attach
failure due to SS7 data configuration problems:

l1. After the cause of access restriction based on IMSI field has been excluded, the MS still cannot
attach successfully:

l2. Based on the attach process analysis, the SGSN will communicate with the HLR and complete
authentication and location updates.

l3. During signaling tracking checks, if the SGSN only sends out a MAP message and does not receive
a response from the HLR, and the SGSN rejects the attach request from the MS,
the rejected cause value is "
PROTOCOL ERROR", "Network
failure
", "GPRS SERVICE NOT ALLOWED in this PLMN" or "GPRS SERVICE NOT ALLOWED". (The rejected cause value is determined by software parameters. The common rejected cause value is the first one).
l4. Now, you can locate the failure point on the Gr
interface.

l5. Based on the SS7 Protocol, inquire in hierarchy bottom-up. First check the hardware and links,
and then the data configuration. Refer to Handling Failures of the
Gr Interface for details.