[Serusers] Theory behind a media proxy and NATed UA

[Felipe Louback]

Andy told that after the first UDP packet is received on the
mediaproxy socket it knows
where to send the packets to. That is the problem.... after the
invite, the NAT-ed UA will wait for traffic, and not send traffic.
Greger, I read Section 3.5 of the document you said, but they dont
explain my doubt. There you can find how the register process is done
and how the NAT problem can be solved. In the document it is said the
proxy put his address in the SDP payload, but how does the media proxy
force the NATed UA to send a UDP packet? By default, the UA is waiting
for audio after it sends an INVITE....

Felipe


On 10/4/05, Greger V. Teigre <greger at teigre.com> wrote:
> Section 3.5 of the ONsip.org Getting Started document provides an intro from
> a SIP/SER point of view.  Tell me if you miss something :-)
> g-)
>
> ----- Original Message -----
> From: "Felipe Louback" <louback at gmail.com>
> To: <serusers at lists.iptel.org>
> Sent: Monday, October 03, 2005 07:27 PM
> Subject: [Serusers] Theory behind a media proxy and NATed UA
>
>
> > The problem with NAT is because the IP address of the SDP body is a
> > non routeable IP. So how does a media proxy works?
> >
> > I read that a media proxy put his address at the sdp body and both UA
> > talks with the media proxy instead of each other. At the time a NAT
> > user sends an INVITE, there is no corresponding port on the NAT. So
> > How does a media proxy contact the NATed UA?
> > Isn't this the same problem the called part will have to contact the
> > NATed party?
> >
> > I read a couple of papers about it, but in all of them it is said that
> > both ends talk to the media proxy and that is all. No explanation
> > about how things work. I know it works because I am using mediaproxy.
> >
> > If anyone could point me how this works or where I can find a document
> > explaining....
> >
> > Thanks,
> >
> > Felipe
> >
> > --
> > Master Student - Electrical Engineering Department
> > Computer Engineering and Telecommunications Research Group
> > Universidade Federal de Minas Gerais - Brazil
> >
> > "For God so loved the world that he gave his one and only Son, that
> > whoever believes in him shall not perish but have eternal life."
> > John 3:16
> >
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> > serusers at lists.iptel.org
> > http://lists.iptel.org/mailman/listinfo/serusers
> >
>
>


--
Master Student - Electrical Engineering Department
Computer Engineering and Telecommunications Research Group
Universidade Federal de Minas Gerais - Brazil

"For God so loved the world that he gave his one and only Son, that
whoever believes in him shall not perish but have eternal life."
John 3:16