diff --git a/channels/chan_sip.c b/channels/chan_sip.c index 32b2a3611fff39739aa48af0a2dd2b2e9c2fc3d4..d6d2df69bea0b2e22f99a3489a6aa0b78e496960 100644 --- a/channels/chan_sip.c +++ b/channels/chan_sip.c @@ -199,23 +199,29 @@ The session-timers parameter in sip.conf defines the mode of operation of SIP session-timers feature in Asterisk. The Asterisk can be configured in one of the following three modes: - 1. Accept :: In the "accept" mode, the Asterisk server honors session-timers requests - made by remote end-points. A remote end-point can request Asterisk to engage - session-timers by either sending it an INVITE request with a "Supported: timer" - header in it or by responding to Asterisk's INVITE with a 200 OK that contains - Session-Expires: header in it. In this mode, the Asterisk server does not - request session-timers from remote end-points. This is the default mode. - 2. Originate :: In the "originate" mode, the Asterisk server requests the remote - end-points to activate session-timers in addition to honoring such requests - made by the remote end-pints. In order to get as much protection as possible - against hanging SIP channels due to network or end-point failures, Asterisk - resends periodic re-INVITEs even if a remote end-point does not support - the session-timers feature. - 3. Refuse :: In the "refuse" mode, Asterisk acts as if it does not support session- - timers for inbound or outbound requests. If a remote end-point requests - session-timers in a dialog, then Asterisk ignores that request unless it's - noted as a requirement (Require: header), in which case the INVITE is - rejected with a 420 Bad Extension response. + 1. Accept :: In the "accept" mode, the Asterisk server honors + session-timers requests made by remote end-points. A remote + end-point can request Asterisk to engage session-timers by either + sending it an INVITE request with a "Supported: timer" header in + it or by responding to Asterisk's INVITE with a 200 OK that + contains Session-Expires: header in it. In this mode, the Asterisk + server does not request session-timers from remote + end-points. This is the default mode. + + 2. Originate :: In the "originate" mode, the Asterisk server + requests the remote end-points to activate session-timers in + addition to honoring such requests made by the remote + end-points. In order to get as much protection as possible against + hanging SIP channels due to network or end-point failures, + Asterisk resends periodic re-INVITEs even if a remote end-point + does not support the session-timers feature. + + 3. Refuse :: In the "refuse" mode, Asterisk acts as if it does not + support session- timers for inbound or outbound requests. If a + remote end-point requests session-timers in a dialog, then + Asterisk ignores that request unless it's noted as a requirement + (Require: header), in which case the INVITE is rejected with a 420 + Bad Extension response. */