[asterisk-users] IAX2 trunking scalability

[Andrew Joakimsen]

On 8/24/07, Jean-Michel Hiver <jhiver at ykoz.net> wrote:
> Hi List,
>
> I have a 2Mbps SDSL link which gets saturated during peak time because
> about I have about 3 E1 worth of g729 traffic going thru. So I'm planning
> to use IAX2 trunking to reduce bandwith requirement and squeeze out each
> and every bit of this (expensive) bandwith.
>
> I've set up two boxes (debian etch), one in a remote data center (which
> has plenty of bandwith) and one behing the SDSL link. To make things
> consistent I've installed the same kernel, latest stable zapata + asterisk
> on both ends.
>
> I've done some tests with about 1/2 E1 (15 channels) worth of calls and so
> far it's been working good - and the call statistics (ASR, ACD, PDD) are
> roughtly the same. So far, so good!
>
> Now the big question is: how far can I expect it to scale? Has anybody
> successfully mounted IAX2 trunking with 3-4 E1s worth of traffic?
>
> Your experience and feedback is appreciated.
>


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.

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.