Question: In an IMS (IP Multimedia Subsystem) scenario with forked requests, what action does a UE (User Equipment) or MGCF (Media Gateway Control Function) take upon receiving a subsequent 200 OK response after already acknowledging a first final 200 OK for an INVITE?
Option 1: Ignore the subsequent 200 OK to avoid dialog conflicts.
Option 2: Acknowledge the subsequent 200 OK and maintain both dialogs.
Option 3: Acknowledge the dialogue and immediately send a BYE to drop the newly received dialog.
Option 4: Update allocated resources without acknowledging the subsequent 200 OK.
Explanation: According to IMS procedures for handling forked requests, upon receiving a first final 200 OK for an INVITE, the UE or MGCF acknowledges it. If a subsequent 200 OK is received (indicating another forked dialog), to maintain a single active dialog and avoid conflicts, the UE or MGCF must acknowledge this new dialogue and then immediately terminate it by sending a BYE, thus dropping the newly established dialog. This ensures resource efficiency and prevents simultaneous, potentially conflicting dialogs.