[Asterisk-Users] IAX vs SIP

[James Golovich]

On Fri, 19 Sep 2003, WipeOut . wrote:

> > I wonder how IAX compares to SIP bandwidth-wise? I've tried both over
> > overseas IP connection, and somehow SIP seemed to work better.
> > 
> > Peter
> > 
> 
> Then try making two or three or more calls at the same time.. :)
> 
> If you setup IAX in trunk mode it uses the same connection for multiple voice streams and so optimises the bandwith usage by reducing the overhead per voice channel.. SIP can't do that..
> 
> Also IAX does not care about NAT so a situation like..
> AST<-->NAT<-->Internet<-->NAT<-->AST
> ..will work fine.. SIP will have problems in a setup like this without the use of specialised NAT routers..
> 

FYI: trunking only works in IAX2 and it requires you to have a zaptel
interface on both endpoints

James