The Via tells the receiver of a request where to send responses The Contact tells the other side where to send requests
The To and From are informational and never used as target addresses. BTW, your To header should not have a port in it. > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED]]On Behalf Of luoqiang > Hi, > > > I am a beginer for sip. > After reading the rfc,I have some questions. > e.g: > ua1: sip:[EMAIL PROTECTED]:5060 > ua2: sip:[EMAIL PROTECTED]:5061 > when ua1 call ua2,the message would be: > > INVITE sip:[EMAIL PROTECTED]:5061 SIP/2.0 > v:SIP/2.0/UDP 10.10.1.1 > f:sip:[EMAIL PROTECTED] > t:sip:[EMAIL PROTECTED]:5060 > i:[EMAIL PROTECTED] > m:[EMAIL PROTECTED]:5061 > c:application/sdp > > Suppose there are no proxies between them. > The message should be forworded to ua2 and ua2 should send a 180 > response. But where does the ua2 get the adress of ua1? > Via?From?Contact? I was puzzled after reading the rfc,because it seems > that all above headers is correct. Which is the ua2's chioce? > > Thanks! > > luoqiang > > > _______________________________________________ > 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
