<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2//EN">
<HTML>
<HEAD>
<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=us-ascii">
<META NAME="Generator" CONTENT="MS Exchange Server version 6.0.6603.0">
<TITLE>NAT=YES</TITLE>
</HEAD>
<BODY>
<!-- Converted from text/rtf format -->
<P><FONT SIZE=2 FACE="Arial">Good morning</FONT>
</P>
<P><FONT SIZE=2 FACE="Arial">Does anyone have experience with NAT=YES? I have the following configuration and am a bit confused as to why the Asterisk server initially sends out RTP to the remote host private IP and then switches to the public IP.</FONT></P>
<P><FONT SIZE=2 FACE="Arial">Configuration Info:</FONT>
<BR><FONT SIZE=2 FACE="Arial">I have all users in SIP.CONF configured with NAT=YES</FONT>
<BR><FONT SIZE=2 FACE="Arial">Asterisk has a public IP</FONT>
<BR><FONT SIZE=2 FACE="Arial">Remote host is behind a firewall with NAT</FONT>
</P>
<P><FONT SIZE=2 FACE="Arial">When I sniff on the Asterisk public network, I see the following.</FONT>
</P>
<P><FONT SIZE=2 FACE="Arial">1. INVITE from remote host public IP to Asterisk public IP</FONT>
<BR><FONT SIZE=2 FACE="Arial">2. 183 response from Asterisk public IP to remote host public IP</FONT>
<BR><FONT SIZE=2 FACE="Arial">3. RTP from Asterisk public IP to the remote host private IP</FONT>
<BR><FONT SIZE=2 FACE="Arial">4. RTP from remote host public IP to Asterisk public IP</FONT>
<BR><FONT SIZE=2 FACE="Arial">5. RTP from Asterisk public IP to the remote host public IP</FONT>
</P>
<P><FONT SIZE=2 FACE="Arial">Is there a way to prevent step 3 from happening? Or, is there a way to delay the invalid RTP from being sent from the Asterisk in step 3?</FONT></P>
<P><FONT SIZE=2 FACE="Arial">Does anyone know why the Asterisk sends RTP to remote host private IP? I would expect NAT=YES to correct this issue.</FONT>
</P>
<P><FONT SIZE=2 FACE="Arial">Thanks,</FONT>
</P>
<P><FONT SIZE=2 FACE="Arial">Peter</FONT>
</P>
</BODY>
</HTML>