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

Step |
Description |
---|---|
1 |
MME sends Create Session Request message to GTPC-EP ingress with the following:
Establishes new transaction at GTPC-EP ingress. |
2 |
SGW service POD receives Create Session Request. |
3 |
SGW service POD Create a new transaction S-T1. |
4 |
Validate Create Session Req. |
5 |
NodeMgr allocates TEID. SGW service POD reads the UPF cache and performs UPF selection. |
6 |
PFCP-EP receives Sx Session Establishment Request from SGW service POD with the uplink and downlink Create PDRs/FARs (Apply Action as Forward)/CTEs. |
7 |
PFCP-EP forwards Sx Session Establishment Request to UPF. |
8 |
PFCP-EP receives Sx Session Establishment Response from UPF with Created CTEs. |
9 |
SGW service POD receives Sx Session Establishment Response from PFCP-EP. |
10 |
Modify Bearer Request with updated S5 SGW Control TEID and S5 SGW Data TEID sent from the SGW service POD to GTPC-EP. |
11 |
PGW receives Modify Bearer Request message from GTPC-EP. |
12 |
GTCP-EP receives Modify Bearer Response from PGW. |
13 |
SGW service POD receives Modify Bearer Response from GTPC-EP. |
14 |
SGW service POD forwards Create Session Response to GTPC-EP ingress. |
15 |
Updated session 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 to old SGW and receives Delete Session Response. Call cleared in old SGW. |