Spent quite a bit of time troubleshooting this and figured it would save someone a lot of time if this was documented<br>
(thanks to drumkilla, file and Juggie for their assistance on this as well).<br>
<br>
Been using Broadvox DIDs to receive incoming calls for over a year now with an older version of asterisk with no problems.<br>
Upgraded to asterisk 1.2.0 and incoming calls stopped working. I would see the call hit asterisk and asterisk would send<br>
a 200 OK SIP reply but Broadvox would not send an ACK. After
analyzing the ethereal captures of my old system and the new system<br>
the only difference was that asterisk 1.2.0 included "Max-Forwards: 70" in the SIP header when replying to Broadvox.<br>
<br>
After many hours of troubleshooting, Broadvox finally said that their switch does not support having "Max-Forwards: 70"<br>
specified in the SIP headers that asterisk sends back to them so they are not able to send an ACK back. They said that <br>
I had to remove the offending statement from the SIP headers in order
for the calls to work. I did so and re-tested and the<br>
calls went through fine.<br>
<br>
Here are the details of what needs to be changed to make asterisk 1.2.0 compatible with Broadvox:<br>
<br>
(assuming your source files are in /usr/src/asterisk)<br>
<br>
1. open /usr/src/asterisk/channels/chan_sip.c for editting<br>
<br>
2. remove each line that mentions "Max-Forwards"<br>
<br>
3. save file and recompile asterisk<br>
<br>
4. Calls from Broadvox work again<br>
<br>
They are aware that Max-Forwards is in RFC-3261 (<a href="http://www.ietf.org/rfc/rfc3261.txt">http://www.ietf.org/rfc/rfc3261.txt</a>).<br>
<br>
Supposedly, Broadvox is working with their vendor to update their switch to support Max-Forwards in the SIP headers.<br>
Until that happens, this is the only way to make asterisk 1.2.0 work with their equipment.<br>
<br>
Hopefully this helps!