<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><br><div><div>On 01/08/2008, at 3:41 PM, Edwin Groothuis wrote:</div><blockquote type="cite"><div><br>There are two reasons why SIP via NAT is a bad idea:<br><br>- Indeed, the SDP packet has the IP address of the media termination<br> points in it. Which will give the famous one way audio if it<br> doesn't get through. STUN to the rescue? Re-invite to the rescue?</div></blockquote><div><br></div>Session Border Controllers - we use Acme Packet (as do a number of others). They massage SIP and make it work.</div><div>Brilliant pieces of work they are. They get around all of these problems and solve NAT pin hole closing issues etc as well as all kinds of fixups as well as working as very clever firewalls to protect your softswitch.</div><div><br></div><div>MMC</div><div apple-content-edited="true"> <span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div>-- <br>Matthew Moyle-Croft Internode/Agile Peering and Core Networks<br>Level 4, 150 Grenfell Street, Adelaide, SA 5000 Australia<br>Email: <a href="mailto:mmc@internode.com.au">mmc@internode.com.au</a> Web: <a href="http://www.on.net/">http://www.on.net</a><br>Direct: +61-8-8228-2909<span class="Apple-tab-span" style="white-space: pre; "> </span><span class="Apple-tab-span" style="white-space: pre; "> </span> Mobile: +61-419-900-366<br>Reception: +61-8-8228-2999 Fax: +61-8-8235-6909<br></div></div></span> </div><br></body></html>