asterisk users - Sep 2004 - Medium volume 100% SIP/IAX PBX.

Hello,

	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.

Thanks for your responses.

--
Kristian Kielhofner

> 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

> 
> 	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.
> 
> Thanks for your responses.
I know of several that are working fine. We've got our small business on
it too, but we're doing BV via a DSL; we have much lower call volume
requirements.

Think about the network infrastructure as well, including UPS's on
switches, routers, and other assets needed to place calls.

Legal folks would also suggest a pots phone (Red Phone) for use in
emergencies (or when asterisk just happens to fail at the wrong time),
employee training on when to use it, etc. Certainly could be bridged 
to * as one of the four local lines that you mentioned.

On Fri, 17 Sep 2004 16:18:52 -0500, Kristian Kielhofner <kris@krisk.org>
wrote:
> Hello,
> 
>        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.
Hi, I have a curiosity: how much does a regular PBX system cost? I'm
curious if using IP telephony in a building is cheaper than a regular
PBX, because of the high cost of the IP phones.

If anyone has commercial experience, and would like to share an
example comparing costs, I would appreciate.

Thanks.