Cisco ASR 5000 series Product Overview page 696

▀ How the SGSN Works
Step Description
2 The SGSN sends Delete PDP Context Request message to the GGSN containing the TEID.
The GGSN sends a Delete PDP Context Response back to the SGSN.
The SGSN stops generating S-CDR info at the end of the PDP context.
3 The SGSN sends a IMSI Detach Indication message to the MSC/VLR.
4 The SGSN sends a GPRS Detach Indication message to the MSC/VLR.
The SGSN stops generating M-CDR upon GPRS Detach.
5 If the detach is not due to a UE switch off, the SGSN sends a Detach Accept message to the UE.
6 Since the UE GPRS Detached, the SGSN releases the Packet Switched Signaling Connection.
▄ Cisco ASR 5000 Series Product Overview
Serving GPRS Support Node (SGSN) Overview
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