[Asterisk-Users] SIP Extension behind NAT, Asterisk on a public domain

[Tom Rymes]

On Nov 23, 2005, at 11:04 AM, Manny A. Wise wrote:

[snip]
> Well, as the user stated on the original message, the asterisk  
> server is behind a NAT and the client is also behind a NAT….
>
> if you make it work just by opening ports, let me know..I have  
> never been able to get it to work, that’s why I don’t use sip, just  
> plain iax2 for everything… J
>
> Manny
>
Manny,

I have this working as I write this. (I just hung up the phone.) In  
fact, I brought a Cisco 7940G to a completely unknown nat-ed network  
the other day, plugged it in and started making calls right away.  
Here's the setup I have for this specific configuration:

1.) Asterisk server behind NAT. (Setup as DMZ on Linksys WRT54G, but  
it's still NAT. I just don't have to forward ports this way)
2.) externip, localnet, nat settings configured in the sip.conf file  
(sip_nat.conf for Asterisk at Home)
3.) Cisco phone (or whatever SIP UA you choose) configured for NAT  
(via the SIP<MAC>.cnf file for Cisco)
4.) Lather, rinse, repeat if necessary

Hopefully that will work for you. I'd rather use IAX and avoid these  
problems altogether, but I have yet to find an IAX hardphone I am  
willing to use. In fact, for softphone use, I do indeed use IAX via  
LoudHush for the mac. (Great piece of software, BTW. No connection  
here, just a happy user...)

Tom

--------------------
Tom Rymes
Cascade Link Systems
www.cascadelinksystems.com
(603) 375-1414

"Intelligent technology solutions for small businesses."