LTE: Bearer Resource Modification Reject

·        If the network cannot accept the bearer resource modification requested by the UE, then the MME shall send a BEARER RESOURCE MODIFICATION REJECT message to the UE.

·        The BEARER RESOURCE MODIFICATION REJECT message shall contain the Procedure Transaction Identity (PTI) which should match the PTI value received in the BEARER RESOURCE MODIFICATION REQUEST.

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

·        If the bearer resource modification requested is for an established LIPA PDN connection, then the network shall reply with a BEARER RESOURCE MODIFICATION REJECT message with ESM cause #60 "bearer handling not supported".

·        If the ESM cause value is #26 "insufficient resources", the network may include a value for timer T3396 value IE in this message. In such a case, the UE should take different actions depending on the timer value as specified in section 6.5.4.4 in 3GPP TS 24.301.

·        After receiving the BEARER RESOURCE MODIFICATION REJECT message, the UE shall stop the timer T3481 and release the traffic flow aggregate description associated to the PTI value.

·        If the ESM cause included in the reject message is #43 "invalid EPS bearer identity", the UE locally deactivates the EPS bearer context(s) without peer-to-peer ESM signalling.

Reference 3GPP TS 24.301

Example:  BEARER RESOURCE MODIFICATION REJECT message