This operation returns the name of the GTP the CTP is associated to. If the CTP is not associated to a GTP, the returnedGTP parameter is left empty.

Operation Exceptions:
1. NOT_IMPLEMENTED - Raised when EMS does not support this operation.
2. INTERNAL_ERROR - Raised in case of non-specific EMS internal failure.
3. NE_COMM_LOSS - Raised when communication to managed element is lost and communication with
    the managed element is needed to determine the GTP the CTP is associated to.
