Radio Access Bearer/Modify Bearer Request Failure and Error Handling
This section covers the Radio Access Bearers (RAB), Modify Bearer Request and Response (MBR) from PGW and User Plane (UP) failure scenarios.
The following table summarizes cnSGW-C behavior during different stages of call processing for various failure types:
Message Type |
Failure Interface |
Failure Response Recevied |
Failure Response to be sent |
Handling |
---|---|---|---|---|
MBR initial attach |
Sx |
CONTEXT_NOT_FOUND |
EGTP_CAUSE_ NO_RESOURCES_ AVAILABLE |
Cleanup PDN with DSR towards PGW and DBR towards MME |
Other Failure Response |
EGTP_CAUSE_ NO_RESOURCES_ AVAILABLE |
Cleanup PDN with DSR towards PGW and DBR towards MME. Sx_Modification_Req/ Sx_Session_Delete to cleanup resource on UP |
||
Timeout |
Timeout on PFCP |
EGTP_CAUSE_ NO_RESOURCES_ AVAILABLE |
Cleanup PDN with DSR towards PGW and DBR towards MME. Sx_Modification_Req/ Sx_Session_Delete to cleanup resource on UP |
|
MBR Service Request |
Sx |
CONTEXT_NOT_FOUND |
EGTP_CAUSE_ NO_RESOURCES_ AVAILABLE |
Cleanup PDN with DSR towards PGW and DBR towards MME |
Other Failure Responses |
EGTP_CAUSE_ NO_RESOURCES_ AVAILABLE |
Do not update anything in PDN, Ignore S5 Signaling |
||
Timeout |
EGTP_CAUSE_ NO_RESOURCES_ AVAILABLE |
Do not update anything in PDN, Ignore S5 Signaling |
||
S5 |
EGTP_CAUSE_ CONTEXT_NOT_ FOUND |
EGTP_CAUSE_ CONTEXT_NOT_ FOUND |
Sx_Session_Delete send to UP MBRsp failure to MME (No DBR/DSR) |
|
Other Failure Responses |
Failure Response received from PGW |
Do not update PDN/DB |
||
Timeout |
Timeout from PGW |
EGTP_CAUSE_ PEER_NOT_ RESPONDING |
Do not update PDN/DB |
|
RAB |
Sx |
CONTEXT_ NOT_FOUND (Single PDN call) |
EGTP_CAUSE_ REQ_ACCEPTED |
Cleanup PDN with DSR towards PGW and DBR towards MME |
CONTEXT_ NOT_FOUND (Multi PDN call and context not found for one PDN) |
Send RAB Resp (EGTP_CAUSE_ REQ_ACCEPTED) |
Cleanup the PDN for which context not found received with DSR towards PGW and DBR towards MME Move other PDN/UE to IDLE |
||
Other Failure Response |
EGTP_CAUSE_ REQ_ACCEPTED |
Move PDN/UE to IDLE |
||
Timeout |
EGTP_CAUSE_ REQ_ACCEPTED |
Move PDN/UE to IDLE |