[Asterisk-Users] Medium volume 100% SIP/IAX PBX.

[Chris Shaw]

> Hello,

Hi

> Does anyone have experience with a %100 all VoIP * setup?  I imagine an
> office with 50 extensions or so, a full T1 connected to a decent ISP and
> an account with NuFone (IAX2 trunking, G729a).  I would need to support
> at least 25 simultaneous outgoing (7960G -> Asterisk -> NuFone -> PSTN)
> phone calls.  I would probably keep four or so analog lines for local
> calls, 411, 911, etc.  Does anyone have any personal experience with
> such a setup?  Would you put YOUR business on it?  I would be willing to
> throw as much money as needed at hardware, dual Xeons, etc, if it would
> at least be possible.

* should have no problem keeping up with a setup like that, and VoIP is
certainly capable.... However... What most interests you? Is it cost savings
or audio quality. If it's cost savings, you could push 25 calls through a T1
using GSM encoding, but it would not sound quite the same as a regular line.
If you use G.711 (mu/A-Law) then you would get toll quality audio but only
be able to push about 17 calls through at once...

Also you must remember that the current RTP implementation in Asterisk is...
somewhat... lacking, and with a 100% VoIP setup you will need a timing
source like ztdummy (which requires a UHCI USB controller) or ZapRTC. Or if
you're using linux 2.6, I don't think you need anything as the internal
timer resolution is precise enough...

Our company is thinking of deploying a setup like this but a bit smaller,
only 12 extensions and at most 8-9 simultaneous calls. I would certainly
recommend a setup like this, it's a huge cost savings. I would also do
plenty of homework and figure out how to do it before actually committing to
it. Maybe even do a parallel setup where you have some POTS lines as a
backup. I would also use some kind of failover where your IAX provider can
forward your incoming calls to another IAX provider's number or a POTS
number during downtimes...

> Thanks for your responses.

You're welcome

    -Chris