IDFT Support with SGW Relocation Call Flow
This section describes the IDFT Support with SGW Relocation call flow.

Step |
Description |
---|---|
1 |
Call is connected with the Source eNodeB and there's a decision to trigger relocation via S1. The MME sends the Create Session Request to the Target SGW-C. |
2 |
The MME receives the Create Session Response from the Target SGW-C. |
3 |
The MME sends the Create IDFT Request to the Target SGW-C. |
4 |
The MME receives the Create IDFT Response from the Target SGW-C. |
5 |
The MME sends the Create IDFT Request to the Source SGW-C. |
6 |
The MME receives the Create IDFT Response from the Source SGW-C. The indirect forwarding of the data starts from the Source eNodeB to the Source SGW-C. The indirect forwarding of the data starts from the Source SGW-C to the Target SGW-C. The indirect forwarding of the data starts from the Target SGW-C to the Target eNodeB. The Target eNodeB sends the Downlink Data to the UE. The Target eNodeB sends the Uplink Data to the Target UP. |
7 |
The MME sends the Modify Bearer Request to the Target SGW-C. |
8 |
The Source SGW-C sends the Modify Bearer Response to the MME. The Target UP sends the End Marker to the Source eNodeB, and the Source eNodeB forwards the End Marker to the Target UP. The Target UP sends the Downlink Data and the End Marker to the Target eNodeB. |
9 |
The MME sends the Delete Session Request to the Source SGW-C. |
10 |
The MME receives the Delete Session Response from the Source SGW-C. |
11 |
The MME sends the Delete IDFT Request to the Source SGW-C. |
12 |
The MME receives the Delete IDFT Response from the Target SGW-C. |
13 |
The MME sends the Delete IDFT Request to the Target SGW-C. |
14 |
The MME receives the Delete IDFT Response from the Target SGW-C. |