Cisco ASR 5000 series Product Overview page 650

▀ How the Serving Gateway Works
Figure 160. Subscriber-initiated Detach Call Flow
UE
Detach Request
1
Detach Response
8
Table 85.
Step Description
1 The UE sends NAS message Detach Request (GUTI, Switch Off) to the MME. Switch Off indicates whether detach is due
to a switch off situation or not.
2 The active EPS Bearers in the S-GW regarding this particular UE are deactivated by the MME sending a Delete Bearer
Request (TEID) message to the S-GW.
3 The S-GW sends a Delete Bearer Request (TEID) message to the P-GW.
4 The P-GW acknowledges with a Delete Bearer Response (TEID) message.
5 The P-GW may interact with the PCRF to indicate to the PCRF that EPS Bearer is released if PCRF is applied in the
network.
6 The S-GW acknowledges with a Delete Bearer Response (TEID) message.
7 If Switch Off indicates that the detach is not due to a switch off situation, the MME sends a Detach Accept message to the
UE.
8 The MME releases the S1-MME signalling connection for the UE by sending an S1 Release command to the eNodeB with
Cause = Detach.
▄ Cisco ASR 5000 Series Product Overview
eNodeB MME
2
Bearer Rsp
7
Signaling
Connection Rel
Subscriber-initiated Detach Call Flow Description
S-GW
Delete
Bearer Req
Delete
3
Bearer Req
Delete
Bearer Rsp
Delete
6
P-GW PCRF
4
PCRF
5
Interactions
Serving Gateway Overview
HSS
OL-22938-02