Question: What action does an en-gNB take if it receives a SGNB ADDITION REQUEST with multiple E-RAB ID IEs set to the same value in the E-RABs To Be Added List IE?
Option 1: The en-gNB sends a SGNB ADDITION REQUEST REJECT message due to security algorithm mismatch.
Option 2: The en-gNB triggers the release of the concerned E-RAB and notifies the MeNB.
Option 3: The en-gNB initiates a SgNB Modification procedure to resolve the conflict.
Option 4: The en-gNB considers the establishment of the corresponding E-RAB as failed.
Explanation: If an en-gNB receives a SGNB ADDITION REQUEST with duplicate E-RAB ID IEs in the E-RABs To Be Added List, it considers the establishment of the corresponding Evolved Radio Access Bearer (E-RAB) as failed. This prevents ambiguity and errors in bearer management between the MeNB and en-gNB.