<span class="Apple-style-span" style="font-family: arial, sans-serif; font-size: 13px; border-collapse: collapse; "><div>My Asterisk server is behind a NAT and I have set:</div><div>----------------------------------------------------------------------------</div>
<div>externhost="my.server.address" </div><div>externrefresh=180</div><div><br></div><div>localnet=<a href="http://192.168.0.0/255.255.0.0" target="_blank" style="color: rgb(119, 153, 187); ">192.168.0.0/255.255.0.0</a></div>
<div>localnet=<a href="http://10.0.0.0/255.0.0.0" target="_blank" style="color: rgb(119, 153, 187); ">10.0.0.0/255.0.0.0</a></div><div>localnet=<a href="http://172.16.0.0/12" target="_blank" style="color: rgb(119, 153, 187); ">172.16.0.0/12</a></div>
<div><br></div><div>nat=yes</div><div>---------------------------------------------------------------------------</div><div>in [general] section of sip.conf.</div><div><br></div><div>I can make perfect conversation with my friend with the only exception of both parties being on private ip address.</div>
<div><br></div><div>There can be four situations when a call is established.</div><div>1. A and B are not behind NATs</div><div>2. A is behind a NAT, but B is not.</div><div>3. A is not behind a NAT, but B is.</div><div>4. A and B are both behind NATs (different NAT of course).</div>
<div><br></div><div>Among the four situations, 1, 2 and 3 works fine. (I guess externhost and localnet did the trick)</div><div>But situation 4 does not work.</div><div><br></div><div>In situation 4:</div><div>When I call my friend, I get only one antenna bar with an exclamation mark. (I am not talking about the iPhone's wifi bar, nor carrier's bar. I am talking about Softphone's bar). But my friend has no problem with the antenna bar. And both of us cannot hear anything.</div>
<div>When he calls me, now he gets one antenna bar and an exclamation mark, but my antenna bar is just fine. And we still don't hear anything.</div><div>One time, there was only one time we could hear each other. He called me and for the first 3~4 seconds, we could hear nothing. But after that we could hear each other. I don't know how it worked. It was just one random success.</div>
<div>This is really weird. I tried Viber in the same situation and Viber works just fine every time. </div><div>Could anyone give me any plausible explanation for this phenomenon?</div><div><br></div><div>Ed </div></span>