What will happen when RRC connection Reconfiguration failure happens during initial attach?

Question

When Fullconfig IE will come with RRC Connection Reconfiguration , during S1-based handover or X2 - based handover
please explain in detail .

Answer 1

E-UTRAN before sending the RRC Connection Reconfiguration message to the UE, activates access stratum security.

There are following two pre-conditions which should be fulfilled before initiating the re-establishment procedure.
1. UE should be in RRC-CONNECTED mode. UE RRC layer state moves from IDLE to CONNECTED soon after completing the RRC connection setup procedure
2. Access Stratum (AS ) security should be activated. It will be done even before sending the RRC connection reconfiguration (carrying SRB2 and DRBs configuration) message from the eNodeB.

Gnanendra, the scenario you mentioned is fulfilling these two properties. As result, RRC Re-establishment Procedure will be initiated by UE.