[asterisk-users] Learn some terminalogy before mounting this task.

James R. Stevens jstevens at athensdistributing.com
Mon Jul 2 16:31:56 CDT 2007


All,

It's been some time since this thread was alive but we are now seeing
some progress in this project. Which I will document.
We have ordered a T1 for the new building which we are moving (We are
getting 14 channels of the T1.) and have a Sangoma A101 card for a 3U
rack server.
The T1 will have B8ZF decoding and ESF framing  which the sangoma card
should handle.

They asked me if we want NI1 or NI2 ?? Is this a reference to the PRI ?

-----Original Message-----
From: asterisk-users-bounces at lists.digium.com
[mailto:asterisk-users-bounces at lists.digium.com] On Behalf Of Pierre
Marceau
Sent: Tuesday, April 10, 2007 11:25 PM
To: asterisk-users at lists.digium.com
Subject: Re: [asterisk-users] Learn some terminalogy before mounting
this task.

James,

I'm sorry that I can't add anything but just wanted you to know that I
am watching this thread with great interest and suspect that many others
will too.

Thanks in advance for posting lots of details as you go thru the
process.

Pierre


>>> abalashov at evaristesys.com 4/10/2007 10:41:36 PM >>>

Hi James,

   Admittedly, the terminological and conceptual barrier may present
some 
impediments to the completeness and specificity of answers, so we might 
have to work at this a bit, but let's see how we can help:

On Tue, 10 Apr 2007, James R. Stevens said something to this effect:

> We have a T1 coming into the building(FYI-Our Voice and Data are on
> separate T's) terminating at the Smart Jack.

   Are you implying that there are two T1 circuits -- one voice, and one

data?  Or do you mean that the T1 is channelised and some of the
channels 
are used for voice and some for data?  That's kind of what it sounds
like. 
Sounds like you can do 7 calls on voice channels and the rest are 
provisioned as a clear-channel data pipe.

   That would mean that you have some equipment for breaking them out on

your premises.  The channel bank would break out the voice lines as FXO 
analogue lines (if you set it to) and those probably feed into your PBX.

The rest of the channels used for data would probably be signaled out on
another T1 interface, but with some subrate DS0 channels missing.
That's 
ust a guess.

   But what you say below suggests that my theory is wrong, so perhaps
it is 
the case that you have separate voice and data T1s after all, even
though 
you refer to it in the singular.

   Do be aware that under no circumstances does anyone generally refer
to a 
T1 as a "T."  :)

> I can tell you our current phone system can handle 7 phone calls at a
> time:
>
>   Does this mean the T only has 7 channels provisioned out of the 24
> possible?

   This is possible.  Do you happen to know what kind of signaling is
used 
on it?  Is it an ISDN PRI, or an E&M trunk?

>  Does a channel (In terms of the T1) = a port?

   A port on what?  The channel bank?

   Channel banks generally do break the DS0s (subrate 64 kbps channels,
of 
which there are 24 on a T1) out, but some more sophisticated ones have
the 
capability to do other things as well.

   If so, the answer is yes.

>  How many phone calls can one TDM400 support concurrently? (four ??)

   If it has four FXO ports and four FXO modules, yes.  They come in 
different combinations.  Some come with 2 FXO (outside POTS lines to CO)

and 2 FXS (plain analogue POTS handsets) ports, etc.

>  Would I be better off getting a Zapata T1 card and forgetting the
> Channel bank all together(Use the digital signal)?

   You could do that.  Personally, the easiest approach I would say
would be 
to order a PRI.  They've probably considerably gone down in prices, too,

especially if you go shopping with some friendly CLECs.  The rule of
thumb 
in the industry is that generally, once you pass the threshold of six or

seven POTS lines, it becomes economical to just order an entire PRI, and

once you do that, there usually aren't *very* considerable savings to be

gained from turning down all but a few channels.  A PRI has 23 channels 
(bearer channels ("B channels")) and one signaling channel ("D
channel"); 
it's a type of T1-based ISDN interface.

   So, you might potentially be able to get 23 in/outbound phone lines
for 
roughly the same cost or a modest increase, which would increase your 
organisation's capacity to do things like conference calling and other 
things which tie up large amounts of outside lines.

   Do beware that if you go this route, PRIs can be ordered as
"inward-only" 
(typically used for modem and termination-only telephony applications
like
voicemail, IVR, conferencing, etc.) or bidirectionally.

> If we go with a Zapata T1 card for the Asterisk server would we be
able
> to provision an analog phone line, for say a FAX machine from it?

   No, not if the card doesn't have FXS ports on it.  But you could get 
another Digium or Digiumlike card that does, even if it's just a 
single-port (like the hugely popular X100P, which is very inexpensive)
and pull that off.

   Let me know what else we can answer, or if I substantially
misunderstood 
your question.

Good luck,

-- Alex

--
Alex Balashov <sasha at presidium.org>
_______________________________________________
--Bandwidth and Colocation provided by Easynews.com --

asterisk-users mailing list
To UNSUBSCRIBE or update options visit:
   http://lists.digium.com/mailman/listinfo/asterisk-users
_______________________________________________
--Bandwidth and Colocation provided by Easynews.com --

asterisk-users mailing list
To UNSUBSCRIBE or update options visit:
   http://lists.digium.com/mailman/listinfo/asterisk-users

-- 
This message has been scanned for viruses and
dangerous content by Athens Hyperion Scanner, and is
believed to be clean.


-- 
This message has been scanned for viruses and
dangerous content by Athens Hyperion Scanner, and is
believed to be clean.




More information about the asterisk-users mailing list