Update Bearer Procedure Call Flow
This section describes the update bearer procedure call flow.

Step |
Description |
---|---|
1 |
PGW receives IP-CAN session modification request from PCRF. PGW creates the Update Bearer Request message to SGW (cnSGW-C). |
2 |
SGW (cnSGW-C) forwards the Update Bearer Request message to MME. |
3 |
MME generates an Update Bearer Response message towards SGW (cnSGW-C). If this bearer modification fails, then the RAN/NAS list included in the response. |
4 |
SGW (cnSGW-C) forwards the Update Bearer Response message to PGW. |