[Serusers] HELP: mediaproxy re-INVITE NAT detection

[Java Rockx]

Klaus,

Thanks. You're right, I don't think mediaproxy has any such test.
Anyhow, late last night I was discussing this with Zeus Ng and he
shared his code with how he handles this.

Here is verbatim, what he told me. It seems to work, but I hope it
doesn't break anything.

Regards,
Paul


How about something like this.

With the initial INVITE,

... Route processing ...
if (caller is natted) {
   subst('/From:(.*)<(.*)>(.*)/From:\1<\2>;nat=yes\3/');
}

call nathelper or mediaproxy

t_on_reply(nat reply route);
t_relay();

In your reply route,

if (callee is natted) {
   subst('/From:(.*)<(.*)>(.*)/From:\1<\2>;nat=yes\3/');
   call nathelper or mediaproxy
   ... Other processing ...

In your loose route,

if (loose_route()) {
   if (method=="INVITE") {
     if (search("my_ser_detect_nat=yes") || (sdp in private address  )) {
       call nathelper or mediaproxy
     }
   }
   on reply route
   t_relay()
}


On Wed, 16 Mar 2005 15:25:35 +0100, Klaus Darilion
<klaus.mailinglists at pernau.at> wrote:
> Hi Paul!
> 
> If you use the nathelper module, you can use force_rtpproxy with the 'l'
> parameter. Check nathelper.c for documentation.
> 
> I don't know if there is an equivalent feature in the mediaproxy module.
> 
> regards,
> klaus
> 
> 
> Java Rockx wrote:
> 
> > Hi All.
> >
> > I'm using ser-0.9.1.
> >
> > Is there a way to determine if mediaproxy is in use for an existing
> > SIP call so that re-INVITE messages can avoid losing audio when one or
> > the other SIP UAs are NATed?
> >
> > We do not proxy RTP streams unless one or more SIP UAs are NATed. But
> > on re-INVITE messages I cannot figure out how to test the destination
> > of the re-INVITE for the UAs NAT status.
> >
> > I've scoured the archives and found a few related articles
> > http://lists.iptel.org/pipermail/serdev/2004-March/001515.html
> > http://lists.iptel.org/pipermail/serusers/2004-March/006806.html
> >
> > But nothing has led me to a solution. I cannot just use
> > lookup("location") and test the nat_flag since that won't always work
> > on re-INVITEs. A mediaproxy function for something like
> > is_existing_session() would be awesome to lookup the Call-ID in the
> > existing mediaproxy sessions.
> >
> > What am I missing?
> >
> > Regards,
> > Paul
> >
> > _______________________________________________
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> > serusers at lists.iptel.org
> > http://lists.iptel.org/mailman/listinfo/serusers
> >
> >
> 
>