Create Bearer Procedure Failure Handling

This section covers the PGW-initiated dedicated bearer creation procedure failure scenarios.

The following table summarizes cnSGW-C behavior during different stages of call processing for various failure types:

Note

During processing of create dedicated Bearer Request and Response, if SGW receives Context Not Found from peer (MME/UP) it deletes the PDN without performing any signaling towards the peer which sent this cause.

cnSGW-C Behavior for Create Bearer Procedure Failure Scenarios

Scenarios

Sx Signaling

(Revert)

S11 Signaling

(Revert)

S5 Signaling

Output

  • Create Bearer Request advance validation failure

  • Sx Session Modify Request failure (request sent to UP to allocate tunnel endpoint and GTPU TEIDs).

No

No

Negative - Create Bearer Response to PGW

New Bearer Context is not created.

Create Bearer Request is sent to MME and SGW is waiting for the Response.

Yes

To remove traffic endpoint for newly created bearers.

No

Negative - Create Bearer Response to PGW

New Bearer Context is not created.

Optional parameters of Create Bearer Response are ignored.

SGW receives Create Bearer Resposne from MME and sends Sx Modify to UP to connect GTPU tunnel between eNodeB and SGW-U.

Yes

To remove traffic endpoint for newly created bearers.

Yes

To delete newly created bearers.

Negative - Create Bearer Response to PGW

New Bearer Context is not created.

Optional parameters of Create Bearer Response are ignored.

Failure in Revert handling for the Delete Bearer Request or Sx Modify Request.

No

No

Negative - Create Bearer Response

Bearer Context is not created.

Optional parameters of Create Bearer Response are ignored.