Question: How can the AMF re-bind the NGAP UE association to a new TNL association?
Option 1: By sending a UE-specific NGAP message on a new TNL association (triangular redirection) or by sending a UE-specific NGAP UE-TNLA binding release message to 5G-AN.
Option 2: Only by sending a UE-specific NGAP message on the existing TNL association.
Option 3: By updating the NGAP UE-TNLA binding with the new TNL association without sending any messages.
Option 4: By initiating a new NGAP procedure with the 5G-AN node.
Explanation: The AMF can re-bind the NGAP UE association to a new TNL association by either sending a UE-specific NGAP message on a new TNL association (triangular redirection) or by sending a UE-specific NGAP UE-TNLA binding release message to 5G-AN, which then updates the NGAP UE-TNLA binding with the new TNL association. This allows for flexible management of UE associations in the 5GS network.