3.2.2 Timers
ConnectionTimer: A timer that identifies how much time has elapsed since a session was initiated. If the ConnectionTimer lapses, the server MUST transition to the initial state, which is the equivalent of clearing the state tables and buffers, as specified in [RFC5321] section 2.3.6.
ConnectionInactivityTimer: A timer that identifies how much time has elapsed since a client provided input. If the ConnectionInactivityTimer lapses, the server MUST transition to the initial state, which is the equivalent of clearing the state tables and buffers, as specified in [RFC5321] section 2.3.6.