3.2.2.2.2 Cancel Time-Out Timer
The cancel time-out timer MUST be started when the client call's F_CANCELED flag is set by an external entity in an implementation-specific manner <80>. The timer MUST be canceled when the client receives a QUACK packet whose event ID matches the call's CANCEL_EVENT_ID. If the timer expires, the Call State MUST move into STATE_FAULT.
The default value of the timer SHOULD be infinite. A client application SHOULD be able to specify a value in an implementation-specific way.