[asterisk-users] IAX2 trunking scalability

[Jean-Michel Hiver]

> So you are using an asterisk box as an E1 gateway. You want to know if
> switching from not using IAX trunking to using IAX trunking will have
> any effect? Yes.... it will lower your bandwidth usage a little. It
> will not increase the CPU load. If your system can support x calls it
> will be able to support the same amount of calls.

On about 1/2 E1, it shows that bandwith usage has been about halved - i.e.  
without trunking each G.729 call takes 50 kbps (inbound + oubound) and  
with IAX2 trunking it takes about half of that (using trunkfreq=40). Which  
is good!

I'm wondering wether anybody already had a IAX2 trunking ON and managed to  
push 3 E1s worth of traffic without issues.


> The best thing you can do for your system is add a TC400B card. It
> will also legally support G723 codec which I think sounds just fine,
> but will save you a bit more bandwidth. Using the hardware transcoder
> will greatly increase the number of calls your system would be able to
> handle.

I'm already receiving the calls as g.729, so there is little gain  
(slightly less bandwith usage, slighly worse sound) in doing g.729 ->  
g.723 transcoding - while doing IAX2 trunking vs NOT doing it seems to  
half the bandwith requirement.

Cheers,
Jean-Michel.