UE-Triggered Service Request with PGW Interaction Call Flow
This section describes the UE-Triggered Service Request with PGW Interaction call flow.

Step |
Description |
---|---|
1 |
The MME sends the Modify Bearer Request with s1-eNodeB F-TEID to cnSGW-C when the UE changes from the IDLE to ACTIVE state. |
2 |
The S11-GTP-EP decodes the UDP message and converts it into the gRPC message. This gRPC message is sent to the SGW-Service pod, which handles the UE session using TEID. |
3 |
The SGW-Service pod finds the subscriber context using the local ingress TEID. It validates the Modify Bearer Request content and sends the Sx Modify Request to PFCP-EP. |
4 |
The PFCP-EP sends the Sx Modify Request to the UPF through the UDP proxy. |
5 |
The UPF1 processes the Sx Modify Request and sends the Sx Modify Response message. |
6 |
The PFCP-EP sends the Sx Modify Response message to the SGW-Service pod. |
7 |
The SGW-Service pod detects ULI or UE time zone change and sends the Modify Bearer Request message to S5-GTP-EP. |
8 |
The S5-GTP-EP sends the Modify Bearer Request message to the PGW. |
9 |
The PGW processes the Modify Bearer Request message and sends the Modify Bearer Response message. |
10 |
The S5-GTP-EP sends the Modify Bearer Response message to the SGW-Service pod. |
11 |
The SGW-Service pod moves PDN into the CONNECTED state and sends the update to CDL. The CDL module updates the information in the database. |
12 |
The SGW-Service pod sends the Modify Bearer Response message to the S11-GTP-EP. |
13 |
The S11-GTP-EP sends the Modify Bearer Response message to the MME. The MME processes the Modify Bearer Response message. |