LTE : What may be root cause to send RRC Connection Reestablishment Reject to UE from eNodeB ?

Question

Which message EnodeB will communicate to MME after Receiving the Reestablishment Complete message from UE. what else messages will transverse between EnodeB and MME, before sending Reconfiguration message to UE from EnodeB after Reestablishment complete message has been received at EnodeB.

Answer 1

There might be few causes to send Re-establishment reject message to UE.
1. UE context has been deleted at eNodeB.
2. Short MAC-I validation gets failed.
3. UE sends incorrect cause value in RRC Re-establishment Request message. I means without involving in handover procedure, UE sends handover failure cause in RRC Re-establishment message.