lFault symptom:
pDuring the cutover, the services on a PCU are cut over to another SGSN. After the
cutover, a mobile phone is used to access GPRS services in the cell to which the PCU belongs. The test result is normal. In the following inter-SGSN RAU test, the service handover succeeds when the MS roams from other routing areas to the routing area to which the PCU belongs. The service handover fails when the MS roams from the routing area to which the PCU belongs to other routing areas. The mobile phone is always suspended in terms of the signaling flow. Then, the MS is detached by force.

lFault location:

p1.
Before the cutover, the service handover to other SGSNs succeeds. When the BSC is adjusted to the newly created SGSN, the service handover fails.

 

p2.
The MS can make GPRS services normal on the faulty PCU, which indicates that
the Gb interface on the SGSN works normally after the cutover and the PCU can normally report the RAI to the SGSN.

 

p3.
According to the traced signaling messages, the new SGSN sends a request for
resolving the RA domain name to the DNS after receiving the RAU request reported by the MS. The DNS normally responds to the request. The new SGSN then sends an SGSN_Context_REQ message to the old
SGSN.

p4.
If the domain name is not correctly resolved, this fault occurs.

useful information indeed.

useful document.

This document is very well done

very useful document for my regular O& M activity. Thanks.

clear and useful document, thanks