LTE: PDN Connectivity Reject

·        If the PDN CONNECTIVITY REQUEST cannot be accepted by the network, then the MME shall send a PDN CONNECTIVITY REJECT message to the UE.

·        The PDN CONNECTIVITY REJECT message shall contain the Procedure Transaction Identity (PTI) which should match the PTI value in the PDN CONNECTIVITY REQUEST sent by UE

·        Also, this message shall contain an ESM cause value which indicates the reason for rejecting the UE requested PDN connectivity.

·        The ESM cause IE typically indicates one of the following ESM cause values:

  #8:  operator determined barring

#26:  insufficient resources

#27:  missing or unknown APN

#28:  unknown PDN type

#29:  user authentication failed

#30:  request rejected by Serving GW or PDN GW

#31:  request rejected, unspecified

#32:  service option not supported

#33:  requested service option not subscribed

#34:  service option temporarily out of order

#35:  PTI already in use

#38:  network failure

#50:  PDN type IPv4 only allowed

#51:  PDN type IPv6 only allowed

#53:  ESM information not received

#54:  PDN connection does not exist

#55:  multiple PDN connections for a given APN not allowed

#95 – 111:  protocol errors

#112:  APN restriction value incompatible with active EPS bearer context.

·        If the ESM cause value is #26 "insufficient resources" or #27 "missing or unknown APN", the network may include a value for timer T3396 in the PDN CONNECTIVITY REJECT message. In such a case, the UE should take different actions depending on the timer value and reject cause. Refer to section 6.5.1.4 in the 3GPP TS 24.301 for detailed information

 Reference 3GPP TS 24.301

Example:  PDN CONNECTIVITY REJECT message