>-----Original Message----- >From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] >Sent: Tuesday, February 06, 2007 11:14 AM >To: Sanjay Sinha (sanjsinh) >Cc: [email protected]; >[EMAIL PROTECTED] >Subject: Re: [Sip-implementors] TCP question - Proper way to >Construct ContactURIs > >Sanjay Sinha (sanjsinh) wrote: >> I am not sure if I understand the question, but are you asking about >> how to use the ephemeral port that is created when a UAC sends a >> request, as the port in Contact header? >> If yes, then the port in Contact header should be the local listener >> port on which the UA is listening for sip requests and not the >> ephemeral port. > >I sure hope this is the right way of doing it. It will make my life >less miserable. However wouldn't using the listener address for the >backward direction break NAT?
Yes it will. There are many solutions, there is an outbound technique, for which there is a draft in sip wg, that can be used, you can use STUN etc. > > >> That port will be used by the UAS/proxy to route the >response and is >> not meant to be used for requests in the backward direction. The >> UAS/proxy needs to create another connection in the backward >direction >> on which requests on that dialog will be sent. There are security >> consideration with using the same connection for requests from >> backward direction. >> > >Can you explain what type of security issues this would entail? Pl. see Section 9.3 of connect-reuse (http://www.ietf.org/internet-drafts/draft-ietf-sip-connect-reuse-07.txt ) > > >Thanks! > >Joegen > _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
