Regarding RTP relay (e.g. media proxy), and transcoding --<br><br>This topic has come up many times before in various forms, but I still have not found any obvious solution that&#39;s highly scalable and cheap (well sure, I can dream).&nbsp; We have lots of customers behind various firewalls using various codecs.&nbsp; Customers call each other (both parties behind firewall) and to/from carriers.
<br><br>Certainly this is a common use-case.&nbsp; What do you do?&nbsp; What are best known practices?&nbsp; Commercial media gateway, or open-source solutions?<br><br>We use both OpenSER and a custom B2BUA written against the NIST Java stack.&nbsp; We need a way to transcode when needed.&nbsp; Obviosly mediaproxy module is great, but doesn&#39;t transcode.
<br><br>Ideally, what I&#39;m looking for:<br><br>* at the point where our system determines that transcoding or rtp relay is needed, a media gateway is chosen based on network proximity (e.g.: 1/2 our customers are in the 
U.S., 1/2 in Brazil; should pick a media gateway accordingly to minimize network path).<br><br>* our system then signals the media gateway (mgcp?) to setup the channels, and modifies the SDPs in the SIP path accordingly.<br>
<br>* even more ideally: the media gateway signals our system with inband or rfc2833 dtmf events, plus rtcp reports when available.<br><br>I think Asterisk could be hacked to do this.<br><br>Does anyone know of a commercial product that&#39;s not too expensive?&nbsp; Thoughts? Advice?
<br><br>thanks,<br>-- <br>Ryan Mitchell &lt;<a href="mailto:rjm@tcl.net">rjm@tcl.net</a>&gt;<br>Telecom Logic, LLC<br><a href="http://www.tcl.net">http://www.tcl.net</a>