In biref, this is how it happens. If a proxy receives INVITE message and there is a route header after it has removed its own, then the proxy will use this route header to forward the request.
If a proxy receives INVITE message with no route header and the request-uri's domain it is responsible, then it will replace request-uri with remote target (B's registered address) and shall send the INVITE to B. If a proxy receives INVITE message with no route header and the request-uri's domain it is not responsible for, it shall forward the INVITE using DNS lookup on the domain part of the request-uri (The way our mails are routed from one SMTP server to another using DNS lookup. You need to read RFC-3261 to get into more details. On 4/25/07, varun <[EMAIL PROTECTED]> wrote: > Hi, > could anybody please answer my queries?? > > Thanks > varun > > --- varun <[EMAIL PROTECTED]> wrote: > > > Hi, > > I have some basic doubts: > > 1> Lets say user A calls B and there is a proxy in > > between.So the proxy looks at user part of Request > > URI > > or at the TO field in Invite request to forward the > > call. Both ReqURI and To field in this case would be > > same. > > 2> When is a tel URI used? > > > > 3> When is DNS look up used in Sip call? > > > > Please reply. > > > > Thanks > > varun > > > > __________________________________________________ > > Do You Yahoo!? > > Tired of spam? Yahoo! Mail has the best spam > > protection around > > http://mail.yahoo.com > > _______________________________________________ > > Sip-implementors mailing list > > [email protected] > > > https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors > > > > > __________________________________________________ > Do You Yahoo!? > Tired of spam? Yahoo! Mail has the best spam protection around > http://mail.yahoo.com > _______________________________________________ > Sip-implementors mailing list > [email protected] > https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors > _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
