Session Replacement for Dedicated Bearer Call Flow

This section describes the Session Replacement (SRIR) for Dedicated Bearer call flow.

Session Replacement for Dedicated Bearer Call Flow
Session Replacement for Dedicated Bearer Call Flow Description

Step

Description

1, 2

Initial attach complete.

3, 4

  • UPF sends Sx_Session_Report_Request with report type as SRIR and TEID.

  • cnSGW-C responds with Sx_Session_Report_Response.

5–10

cnSGW-C processes Sx_Session_Report_Request, wrong Session Replacement uses GTPU path failure CLI for peer-signaling or local purge.

If TEID is received for dedicated bearer, submit internal transaction (T2) to clean up bearer.

If CLI, gtpu-path-failure s1u/s5u signal-peer

  • Send Sx_Session_Report_Request to UPF to set FAR ACTION=DROP.

  • Send Delete Bearer Req to MME.

  • Send Delete Session Request to PGW.

11, 12

  • Send Sx_Session_Modification_Request (Remove Traffic Endpoint)

  • UPF responds with Sx_Session_Modification_Response.