LTE: Modify EPS Bearer Context Reject

·        If the MODIFY EPS BEARER CONTEXT REQUEST message cannot be accepted by the UE, then it sends a MODIFY EPS BEARER CONTEXT REJECT message to the MME.

·        This message shall include the EPS bearer identity and an ESM cause value indicating the reason for rejecting the EPS bearer context modification request

·        The MODIFY EPS BEARER CONTEXT REJECT message contains an ESM cause that typically indicates one of the following ESM cause values:

#26: insufficient resources

#41: semantic error in the TFT operation

#42: syntactical error in the TFT operation

#43: invalid EPS bearer identity

#44: semantic error(s) in packet filter(s)

#45: syntactical error(s) in packet filter(s)

#95 – 111: protocol errors

·        Upon receipt of the MODIFY EPS BEARER CONTEXT REJECT message with ESM cause value other than #43 "invalid EPS bearer identity", the MME shall stop the timer T3486 and abort the EPS bearer context modification procedure.

·        If the network receives the MODIFY EPS BEARER CONTEXT REJECT message with ESM cause #43 "invalid EPS bearer identity" the MME locally deactivates the EPS bearer context(s) without peer-to-peer ESM signalling

Reference 3GPP TS 24.301

Example:  MODIFY EPS BEARER CONTEXT REJECT message