Path Failure for Default Bearer Call Flow

This section describes the Path Failure for Default Bearer call flow.

Path Failure for Default Bearer Call Flow
Path Failure for Default Bearer Call Flow Description

Step

Description

1, 2

Initial attach complete. cnSGW-C saves non-unique GTPUPeerKey (NodeID:Remote GTPU-peer-IP) per bearer.

3, 4

  • Path failure detected on UPF. UPF sends NodeReportRequest to Node Manager.

  • Node Manager responds with NodeReportResponse.

  • Initiate Bulk Cleanup request to CDL.

6, 7

  • CDL sends ClearSubNotification to RestEp.

  • RestEP forwards it to cnSGW-C.

8–13

cnSGW-C processes Clear Subscriber Request.

If GTPU peer IP received is for default bearer, submit internal transaction (T2) to clean up PDN.

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.

14, 15

  • Send Sx_Session_Delete_Request.

  • UPF responds with Sx_Session_Delete_Response.