PS Attach Failure Scenario 3 (Access Control According to the User IMSI)

selim.hasan
selim.hasan  Diamond  (1)
5 years 8 months ago  View: 1166  Reply: 0

lA. Locating an access restriction failure based on the subscriber IMSI field:

l1. After PLMN and
License failure is excluded, check the signaling trace. If after receiving the
"
Attach Request" message, the SGSN rejects the MS attach request immediately, the rejected cause value is: "GPRS service not allowed", "Location Area not allowed",  "No suitable cells in LA", or "Roaming not allowed in LA" (The rejected cause value is determined by data configuration, which determines whether change rejected cause value or not. The common rejected cause value is the first one). Note that the rejected cause value does not trigger a MAP message. Then, check whether the SGSN side starts to perform the following functions: restricting subscriber roaming based on IMSI, preventing 2G subscribers from attaching the 3G network based on IMSI, or preventing 3G subscribers from attaching the 2G network based on IMSI.

l2. In this scenario, attach failures mostly occur due to operator’s strategies, which is normal and
requires no action.

l3. You can run corresponding commands to query whether the SGSN restricts the attach based on
the IMSI field: "
LST SERVICE_PARA: ROAM=YES, IMSIREJGPRS=YES, IMSIREJUMTS=YES