UE-requested or the MME-requested PDN Disconnection Call Flow

This section describes the UE or the MME-requested PDN disconnection call flow.

UE-requested or the MME-requested PDN Disconnection Call Flow
UE-requested or the MME-requested PDN Disconnection Call Flow Description

Step

Description

1

The MME sends the Delete Session Request to the S11-GTP-EP for other PDN disconnection.

2

The GTP-EP decodes the received UDP message and converts the message into the gRPC message.

Based on the TEID value, the gRPC message is forwarded to the SGW-service pod which can handle the UE session.

3

The SGW-service pod finds the subscriber context information as per the local ingress TEID.

The SGW-service pod validates the Delete Session Request content. The SGW-service pod sends the Sx Modify Request to the PFCP-EP with apply action as DROP to drop the uplink or downlink packets at the SGW-U.

4

The PFCP-EP sends the Sx Modify Response to the SGW-service pod.

5

The SGW-service pod forwards the Delete Session Request to the S5-SGW-EGRESS-GTP-EP.

6

The S5-SGW-EGRESS-GTP-EP forwards the Delete Session Request to the PGW through the UDP proxy.

7

The PGW sends the Delete Session Response to the S5-SGW-EGRESS-GTP-EP.

8

The S5-SGW-EGRESS-GTP-EP forwards the Delete Session Response to the SGW-service pod.

9

The SGW-service pod validates the Delete Session Response, and sends the Sx Delete Request to the PFCP-EP.

10

The SGW-service pod receives the Sx Delete Session Response from the PFCP-EP.

11

For the last PDN, the SGW-service pod sends the NodeMgrResourceManager Request for the ID release to the NodeManager.

12

The Node Manager releasees the ID and sends the acknowledgment to the SGW-service pod.

13

The SGW-service pod sends the Delete Session Response to the S11-GTP-EP.

14

The S11-GTP-EP forwards the Delete Session Response to the MME.

15

The SGW-service pod

  • Updates the session in database for the delete PDN information for other than the last PDN

  • Sends the delete session message to the database for the last PDN