The ALG providing user access control intermediary services must provide a logoff capability for user-initiated communications sessions.

If a user cannot explicitly end a session, the session may remain open and be exploited by an attacker. However, for some types of interactive sessions including, for example, remote logon, information systems typically send logoff messages as final messages prior to terminating sessions. This policy only applies to gateways (e.g., identity management or authentication gateways) that provide user account services as part of the intermediary services.