TAU X2 Handover SGW Relocation to cnSGW-C Call Flow
This section describes the TAU X2 handover SGW telocation to cnSGW-C call flow.

Step |
Description |
---|---|
1 |
MME sends Create session Req to GTPC-EP ingress with the following:
Establishes new transaction at GTPC-EP ingress. |
2 |
GTPC-EP ingress forwards Create Session req to SGW service POD. |
3 |
SGW service POD receives Create Session Req. Create a new transaction S-T1. |
4 |
Validate CSReq. NodeMgr performs TEID allocation. |
5 |
SGW service reads UPF Cache and performs UPF selection. |
6 |
PFCP-EP receives Sx Session Establishment Req from SGW service POD with the following:
|
7 |
PFCP-EP forwards Sx Session Establishment Req to UPF. |
8 |
PFCP-EP receives Sx Session Establishment Response from UPF. |
9 |
SGW service POD receives Sx Session Establishment Response from PFCP-EP. |
10 |
SGW service POD sends Modify Bearer Req with updated S5 SGW Control TEID and S5 SGW Data TEID to GTPC-EP. |
11 |
GTPC-EP forwards Modify Bearer Request to PGW. |
12 |
GTPC-EP receives Modify Bearer Response from PGW. |
13 |
GTPC-EP forwards Modify Bearer Response to SGW service POD. |
14 |
SGW service POD forwards Create Session Response to GTPC-EP ingress. |
15 |
Session updated at CDL. Transaction S-T1 completed. |
16 |
GTPC-EP ingress forwards Create Session Response to MME. |
17 |
MME sends Delete Session Request with SI=1 sent to old SGW and receives Delete Session Response. Call cleared in old SGW. |