Talon
0dad40c9d7
A Wi-Fi to cellular switch left the session visibly dropping: the media transport rebound itself within a few seconds, but nothing noticed the blackholed control connection until an unanswered keepalive proved it, and the teardown that followed announced a lost connection and waited another second before dialling again. Watch the system path on iOS and fail the control connection the moment the carrying interface changes, which is the only path change TCP cannot survive. Roaming between access points and a link that is merely unusable for a while keep the same interface and the same source address, so ControlPathWatcher reports neither; an unsatisfied path holds the last signature rather than reporting, so a reconnect is never started into a route that cannot carry it. Tighten the keepalive window on the phone as the backstop for what the monitor cannot see, run the first reconnect attempt immediately, and defer the lost-connection announcement until an attempt has actually failed, so a sub-second handover is silent and only a real outage is announced. A control reconnect still re-authenticates and rejoins: the media keys come from the TLS exporter of the connection that was lost, so seamless handover needs control-plane session resumption rather than a faster reconnect.