Create Session Request
The SMF supports the following causes in the Create Session Request message.
Cause |
SMF Behavior |
---|---|
Missing or unknown APN |
If the configured DNN does not match the DNN received in the Create Session Request, then the SMF rejects the message with this cause value in the Create Session Response and sets the appropriate disconnect reason. |
User authentication failed |
If the SMF receives a failed AAA secondary authentication response from RADIUS, then SMF rejects the message with this cause value in Create Session Response. This cause indicates that the request is rejected due to failure in authentication or security procedure and sets the appropriate disconnect reason. |
APN access denied – no subscription |
If the SMF receives the subscription fetch failure response from the UDM, then the SMF rejects the message with this cause value in the Create Session Response. This cause indicates that the SMF has denied the user access to an APN because the subscriber does not have the necessary subscription. SMF also sets the appropriate disconnect reason. |
New PDN type due to single address bearer only |
If the Dual Address Bearer Flag (DAF) indication is not set and the requested PDN-type is IPV4V6 in Create Session Request message, then the SMF rejects the message with this cause value in Create Session Response. SMF also sets the appropriate disconnect reason. |
Late Overlapping Request |
The Create Session Request message includes the Origination Time Stamp indicating the absolute time at which the request is initiated (as specified in clause 13.2.2, TS29.274). If SMF receives any subsequent CSR from different S-GW and different sequence number with older timestamp in "Origination Time Stamp" than the time stamp stored for the existing session, then SMF rejects the new CSR with this cause value in Create Session Response. This cause indicates the incoming request collides with an existing session that does not have a recent time stamp than the time stamp of the new request. If the timestamp is newer, then SMF aborts the current procedure and handles the new CSR request with the recent time stamp. |
Timed Out Request |
If the incoming CSR received origination-time-stamp and maximum-wait-time IEs, SMF starts the SLA timer with maximum-wait-time value at the start of the Create procedure and aborts the Create procedure on expiry of the timer. Then SMF rejects with this cause value in CSR Response. |
New PDN type due to network preference |
If the session type configured under profile dnn is IPv4 or IPv6, and the requested PDN type coming in Create Session Request is IPv4v6, then SMF rejects the message with this cause value in Create Session Response. |