This writable value configures, in seconds, ATM signaling timer T301, which starts when an ALERT message is received in the Call Received state and is normally stopped once a CONNECT message arrives, with the call cleared if the timer expires first. It lets an admin control how long the switch will wait for a called party to actually answer (send CONNECT) after alerting before giving up on the call. For example, an admin supporting long-ringing endpoints might raise T301 toward its 240-second maximum so slow-to-answer calls aren't cleared prematurely.