Question: In UTRAN Iur interface RNSAP signalling, when a receiving node supports a procedure but cannot perform a requested functionality marked as “shall” be executed, how shall the receiving node respond?
Option 1: Ignore the request and continue with ongoing procedures.
Option 2: Respond with a success message, assuming an alternative action.
Option 3: Proceed with the execution of the Elementary Procedure (EP), excluding the unsupported functionality.
Option 4: Respond with a message reporting an unsuccessful outcome, containing an appropriate cause value.
Explanation: According to procedure logic principles, if a receiving node supports a procedure but cannot perform a certain “shall” functionality, it must respond with a message indicating an unsuccessful outcome, including an appropriate cause value to inform the requesting node about the failure.