UE-Triggered Service Request without PGW Interaction Call Flow
This section describes the UE-Triggered Service Request without PGW Interaction call flow.

Step |
Description |
---|---|
1 |
The MME sends the Modify Bearer Request message with s1-eNodeB F-TEID to cnSGW-C when the UE changes from IDLE to ACTIVE state. |
2 |
The S11-GTP-EP decodes the UDP message and converts it into gRPC message. This gRPC message is sent to the SGW-SVC pod (which can handle this UE session) using TEID. |
3 |
The SGW-SVC pod finds the subscriber context using the local ingress TEID. The SGW-SVC pod sends the Modify Bearer Request content and sends Sx Modify Request to PFCP-EP. |
4 |
The PFCP-EP sends Sx Modify Request message to UPF through the UDP proxy. |
5 |
The UPF process the Sx Modify Request message and sends Sx Modify Response message to PFCP-EP. |
6 |
The PFCP-EP sends the Sx Modify Response message to SGW-SVC pod. |
7 |
The SGW-SVC pod chnages PDN into CONNECTED state and sends session update to CDL. The CDL module updates the information in the database. |
8 |
The SGW-SVC pod sends the Modify Bearer Response message to the S11-GTP-EP. |
9 |
The S11-GTP-EP sends the Modify Bearer Response message to MME. The MME processes the Modify Bearer Response message. |