[asterisk-tech] Price of Implementation

HILL David David.Hill at alcatel.co.za
Mon Jun 19 16:34:42 SAST 2006

We have many sites with 2 x 4 port Sirrix ISDN BRI cards and Digium Analog
cards in the same system and they work just fine! Sirrix has a dedicated
device driver and channel driver for Asterisk as well as a voice processor
on the card to cope with the load. The Sirrix cards link together via a
dedicated bus (on the card using an IDE cable to link them, timing and
synchronization runs over this bus). These cards are more expensive than
hacking together a couple of ISDN modems and using a generic channel driver,
but the significantly better voice quality and lack of unhappy users are
more than compensation. 

Once again Rob is the pricing dude.

-----Original Message-----
From: tech-bounces at asterisk.org.za [mailto:tech-bounces at asterisk.org.za] On
Behalf Of Rory Whittal
Sent: Monday, June 19, 2006 4:26 PM
To: Asterisk Tech
Subject: Re: [asterisk-tech] Price of Implementation

Again thanks for the info.

The idea is to get rid of the Jupiter unit and have asterisk take over 
all that.  Hence all the questions

Barry Gill wrote:

> > I need to know what a DDI is?
> DDI (Direct Dial Inbound/Inward (many asterisk users refer to this as 
> DID -
> Direct Inward Dial)
> DDI numbers are logical number allocated the the physical number that 
> exists
> for your telephone line.
> Telkom pass the last four digits of the DDI number to your PBX so that you
> can decide what to do with the call based on the number that was dialed.
> I have for example 20 DDI numbers ranging from 0115555460 to 0115555479
> 5479 is my fax line, 5460 is my default number and numbers 5461 to 
> 5478 are
> used for all sorts of other things, including direct extensions, my 0861
> number etc.
> The same can be achieved with MSN numbers.
> > Also, if I understand Barry correctly, then I only need a couple of ISDN
> lines to run my 5 incoming
> > lines and these can be routed through BRI cards to all my extensions. Am
> I correct in my understanding?
> Yes, you are right.
> BUT....
> ISDN BRI cards are not ideal for telephony.
> I have two duxbury ISDN BRI PCI cards, meaning I have to use 2 PCI slots,
> use 2 IRQ's on my machine.
> If I had more than 2 cards (as you require 5 lines) then having 3 PCI 
> cards
> is not going to work very well as the IRQ allocation and CPU cycle
> allocation because of the number of interrupts will play havoc with my 
> timing.
> This will lead to choppy calls, certainly far from ideal.
> You can get a multi port BRI card from Digium (I am sure Rob can give you
> pricing here) although if you get a muliport card, you will probably 
> (seeing
> as you have a jupiter in place) find it easier to get a 24 port FXO/FXS
> card, have the timings controlled by that and plug your analogue telphone
> extensions and external lines into that...
> You can still do MSN's in that fashion, telkom will still hunt across all
> lines as well...
> Barry
>asterisk tech mailing list
>tech at asterisk.org.za

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