Hi, Paulo, I think IETF has recommended the CR/LF mechanism for SIP over TCP, although I'm quite not sure for NAT case. Please check out the following link;
http://www.softarmor.com/sipwg/meets/ietf61/notes/minutes-sip-ietf61.html "1. TCP keepalive every periodic number of seconds? CRLF? REGISTER? New message (PING)? Comments: - REGISTER is horrifically expensive - not a general solution - CRLF doesn't generate an application ACK - have to wait for TCP keepalives. question about if standard TCP interface allows check. We think we can check unacked bytes in most(?) socket interfaces and use CRLF. " Regards, Jun -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Paulo de Arruda Borelli Sent: Saturday, August 13, 2005 4:00 AM To: [email protected] Subject: RE: [Sip-implementors] keep alive with NAT in SIP Hi, Rakesh, You can use the expires value of the REGISTER messages. Just configure the proxy to require a low expires value (like 60 seconds). This will force the endpoint o re-register again every 60 seconds. In fact, in less than 60 seconds - because, if they re-register exactly every 60 seconds, they will certainly lose registration until the new registration gets active. Some endpoints will re-register at 50% of expires (30 seconds, in this case); some will at 90%. But they usually re-register at less than the nominal expires value. The idea is that this will force the NAT pinhole to be open all the time - enabling inbound flow (from the proxy to the endpoint) to reach the endpoint. Some brands (of endpoints) also support the OPTIONS method as keep-alive mechanism. This will also keep the NAT pinhole open. But the re-register method is great - since it's usually supported. Notice it's imperative that the proxy force expires to a low value. Usually, the endpoints send a default value of 1800 or 3600 seconds - and not always configurable. To keep the NAT pinhole open, it's imperative to re-register at less than one minute. Paulo Borelli -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Nataraju A B Sent: Friday, August 12, 2005 5:37 AM To: 'Rakesh Dhandhukiya'; [email protected] Subject: RE: [Sip-implementors] keep alive with NAT in SIP Regards, Nataraju A.B. -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Rakesh Dhandhukiya Sent: Tuesday, August 09, 2005 1:03 PM To: [email protected] Subject: [Sip-implementors] keep alive with NAT in SIP Hi ! I want to keep alive with NAT. First of how to know the keep alive timeout of NAT for UDP. Is there any file like tcp timeout ? Is ICE used for NAT keep alive? [ABN] service provider may not disclose these timer values... only way to find out these timer values would be to use trail and error method.... I don't think ICE been used to NAT keep alive... Thanks. Rakesh Dhandhukiya _______________________________________________ Sip-implementors mailing list [email protected] http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors _______________________________________________ Sip-implementors mailing list [email protected] http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors _______________________________________________ Sip-implementors mailing list [email protected] http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors _______________________________________________ Sip-implementors mailing list [email protected] http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
