X2 Handover SGW Relocation with Bearer Context Marked for Removal Call Flow
This section describes the X2 handover SGW relocation with bearer context marked for removal call flow.

Step |
Description |
---|---|
1 |
GTPC-EP ingress receives Create Session Req with the following:
Establishes new transaction at GTPC-EP. |
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 allocates TEID. |
5 |
SGW service POD 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 with Created CTEs. |
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 sends Create Session Response to GTPC-EP ingress with cause Accepted for both Bearer Contexts. |
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. |
18 |
MME receives Delete Session Response. Call cleared in old SGW. |
19 |
GTPC-EP ingress receives Delete Bearer Command for Bearer Context from MME to delete (EBI 6). |
20 |
SGW service POD receives Delete Bearer Command from GTPC-EP ingress. |
21 |
SGW service POD forwards Delete Bearer Command to GTPC-EP. |
22 |
GTPC-EP forwards Delete Bearer Command to PGW. |
23 |
PGW responds with Delete Bearer Request (EBI 6) to GTPC-EP. |
24 |
GTPC-EP forwards Delete Bearer Request to SGW service POD. |
25 |
SGW service POD processes Delete Bearer Request and sends to GTPC-EP. |
26 |
GTPC-EP ingress forwards Delete Bearer request to MME. |
27 |
MME responds with the Delete Bearer Response to GTPC-EP ingress. |
28 |
GTPC-EP ingress forwards Delete Bearer Response to SGW service POD. |
29 |
SGW service POD processes Delete Bearer Response and sends to GTPC-EP. |
30 |
GTPC-EP forwards Delete Bearer Response to PGW. |