Cisco ASR 5000 Series Administration Manual page 49

Serving Gateway Overview
Figure 7.
U E
D e ta ch R e q u e st
1
D e ta ch R e sp o n se
8
Table 2. Subscriber-initiated Detach Call Flow Description
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.
OL-22986-01
Subscriber-initiated Detach Call Flow
e N o d e B M M E
2
B e a re r R sp
7
S ig n a lin g
C o n n e ctio n R e l
S -G W
D e le te
B e a re r R e q
D e le te
3
B e a re r R e q
D e le te
B e a re r R sp
D e le te
6
Cisco ASR 5000 Series Serving Gateway Administration Guide ▄
How the Serving Gateway Works ▀
P -G W P C R F
4
P C R F
5
In te ra ctio n s
H S S