I am working on a network and am experiancing CM Service after immediate assignment and reject with cause 101 “message incompatible with protocol stack”. This was experianced in a script testing where SMS was sent before this Call attempt. Looking for reasons for this rejection cause. All ideas / suggestions welcome.
The CM Layer is the NAS layer entity and Plays a Vital Role during the Call Set up. One of the reasons, for the CM service Reject Message could be the Failure in the Security procedures. I would recommend checking the IMSI values on the SIM. Are you running this test case on a simulator ??