asterisk users - Oct 2005 - Re: T1 questions - could I got VoIP instead?

>> yes, its irrelavent what the channels within a channelized T1 do, but 
>> with
> a pri is more complicated FWIW forget about PRI in Canada, no one seems to
> want to offer it. With channelized you need a drop and insert channelbank,
> fxs ports on the channels for extensions, and another T1 out from it with
> just the 6 channels left you want for the outside lines.
>
> Caveat - at least in Canada, 6 channels in a T1 is not worth it, go with 6
> analog lines of whatever type you need fed to the appropriate channel bank
> ports - DID and/or regular trunks, last time I dealt with it which has
> been a while now you could only get inbound DID, so you need regular lines
> to call out in addition. If you do find a cheap provider for sparse
> populated T1's let me know, but a couple years ago you were paying $700
> for the loop from Bell, and then whatever you actually wanted in it
> (dsx's, FR, etc) on top of that.
>
> I have a single t1 card and a 8x16 channel bank attached with 8 line ports
> and 16 extensions
>
>
> at least in Canada, ordering anything beyond a loop start trunk is not for
> the weak of heart, you have to be sure of what you want, and don't take
no
> for an answer from anyone at the telco. You will probably have to go
> through about 3 layers of call jockies before you get anyone who remotely
> understands what you want. Then expect it to get done wrong the first time
> they attempt it so allow lots of extra time. My personal tip - wear a
> headset phone, take a washroom break and have a snack near you, then take
> a deep breath and call, its going to take a while.

Thanks for the Canadian perspective Joe.  I'm living this right now, just 
trying to find out prices from Bell Canada.

I have (yet another) follow-up question...my hypothetical company had 24 
external lines and 72 internal employees.  Which is why a T1 was the answer. 
Now that I think of it, couldn't I use VoIP instead for the external lines 
(I'm not looking at the internal lines right now, just trying to figure out 
whats cheaper for outside access).

Meaning, couldn't I have 72 phone number coming in throught my VoIP 
provider, sent to my Asterisk PBX through normal Internet plumbing and then 
channel it to whatever internally.

This seems obvious, but since nobody mentionned it to me I'm afraid I'm 
probably forgetting about an important obstacle to doing it.

Mike

Hy,
    any one of you know a way to enter an extensions in a context as soon as 
the phone is hooked up? I would like to find a way to alert the internal 
users that a new message is present in voce mail, so as soon as they take 
the phone to place a call the system alerts for the presence of new messages 
and only after this lets the user place the call (or access the voice mail).

Regards,
    Andrea Frigo

On Oct 21, 2005, at 9:37 AM, Micha?l Gaudette wrote:

[snip]
> I have (yet another) follow-up question...my hypothetical company  
> had 24 external lines and 72 internal employees.  Which is why a T1  
> was the answer. Now that I think of it, couldn't I use VoIP instead  
> for the external lines (I'm not looking at the internal lines right  
> now, just trying to figure out whats cheaper for outside access).
>
> Meaning, couldn't I have 72 phone number coming in throught my VoIP  
> provider, sent to my Asterisk PBX through normal Internet plumbing  
> and then channel it to whatever internally.
Mike,

You could easily do this, but keep in mind you will probably need a  
full T1 of data bandwidth (1.5mb/s) to handle the call volume. This,  
of course, depends on the codec used, which will, in turn, affect  
your CPU load... Don't forget about QOS, too, and you might want to  
consider using a dedicated data line for the voice traffic, just in  
case your 50 windows clients all download the latest 5MB update via  
automatic update. (that tends to have a negative effect on your QOS  
for voice traffic!)

Anyhow, I think you will find that the ITSP/VOIP route will be very  
workable, but it will also be somewhat less reliable, simply because  
the PSTN is so darned reliable. In the event that you choose this  
route, you won't need the equipment for incoming lines, since they  
all come in via ethernet.

Tom
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