Timer T316, in milliseconds, controls the retransmission interval for a RESTART message, which this port sends to reset the signaling state of one or all SVCs (for example after a suspected state mismatch with the far end). Because RESTART is a fairly disruptive recovery mechanism that can clear multiple active calls at once, this timer determines how aggressively the port retries a restart request if RESTART ACKNOWLEDGE doesn't come back, and how quickly it escalates. On a stable trunk you would rarely see svcAtmConfigQ93bNumRestartPduTx increment at all, so a T316 value of, say, 30000 milliseconds mainly matters during rare recovery events rather than day-to-day traffic.