Hi, Have you thought of using a Retry-After parameter as listed at: http://www.iana.org/assignments/sip-parameters? Normally a custom parameter is prefxied by a "p" I think, eg pKeepAlive: Further reading the SIP standard at: http://www.ietf.org/rfc/rfc3261.txt has found: Retry-After: 18000;duration=3600 Retry-After: 120 (I'm in a meeting) Can you provide any further info? Oliver On 18/09/2007, Hitesh Tewari <htewari at hotmail.com> wrote: > > Hi, > > Is there a mechanism in SIP to allow for user defined fields to be sent along with a SIP message. > Specifically I would like to periodically send some user defined fields with the re-INVITE (keep alive) > method from my SIP phone. I am assuming that the VoIP provider is able to deal with the parameters > in some proprietary way. I would be grateful for any pointers. Thanks. > > Hitesh > _________________________________________________________________ > See their smiles, hear their laughter with Windows Live Messenger! > http://get.live.com/en-ie/messenger/overview > _______________________________________________ > Visit our blog: http://blog.pjsip.org > > pjsip mailing list > pjsip at lists.pjsip.org > http://lists.pjsip.org/mailman/listinfo/pjsip_lists.pjsip.org >