[asterisk-users] IAX and NAT Transparency

[Gordon Henderson]

On Sun, 20 Jan 2008, bilal ghayyad wrote:

> Hi All;
>
> Did anyone try to use IAX IP Phone behind NAT, and let
> it receive calls from Asterisk without doing port
> mapping at the router existed at the site where the
> IAX IP Phone existed? Is the need just to let the IAX
> IP Phone that is NATed to register on the Asterisk and
> at asterisk I set nat=yes for the IAX client
> configuration?

Yes is the easy answer.

I do this all the time fromn my laptop at friends/colleagues/other 
locations where I get a broadband connection, and don't ever fiddle with 
their routers.

> Or it is impossible to let the NATed IAX to receive
> calls without doing a port mapping at the router?

Not impossible at all.

You *may* find that some routers don't like it, but the majority of them 
are just fine.

> What about SIP, any luck?

Same again, it "just works". Not router fiddling required. I visit client 
sites with a small number of differnet SIP phones - plug them into their 
network and let them make calls, and unless they have weird routers with 
broken SIP ALGs or strict firewalling, it "just works".

We've been through this with you recently. Are you not getting list 
emails?

What about google or the VoIP WiKi? There is plenty of stuff there all 
about it. I can easilly make SIP calls from SIP phones behind a NAT router 
to an asterisk box behind a different NAT router. It just works and there 
is a good page on the VoIP WiKi all about it.

Go read this:

   http://www.voip-info.org/wiki-Asterisk+SIP+NAT+solutions

(Although I don't think that page is quite correct as I can make their '3' 
scenario "just work" ...)

Gordon