[Asterisk-Dev] Hardware details for the Digium TDM400P

[Eric Wieling]

On Sat, 2004-09-18 at 07:30, list at asd-group.com wrote:
> Is anyone away of where there are some basic hardware/functional specs
> for the above card??

I believe the chip is called "ProSLIC"  See:
http://www.google.com/search?hl=en&ie=UTF-8&q=site%3Alists.digium.com+proslic&btnG=Google+Search
The TDM400P card is for ANALOG FXO and FXO lines.

> I’ve spent a frustrating day searching around and come up with
> nothing. What processing does it do on-card? What is left to software?
> What are its limitations? How does it interface with the PC? What does
> a driver have to do?

As I understand it Digium cards are somewhere between a rock and a
turnip when it comes to on board processing power.  This is a Good Thing
from the standpoint of cost.  The smarter the card the more expensive
the card will be.  Smart telephony/DSP cards can run on very low end
equipment.  I seem to remember reports on the Asterisk-Dev mailing list
about people running four T-1 lines into a 486 machine using Dialogic
boards (just for IVR stuff, not using Asterisk).  You could never do
that with a Digium card.  Dialogic boards are MUCH more expensive than
Digiumc cards.  It really comes down to this: Smart (expensive) DSP
cards can be run on slow PCs.  Dumb (cheap) DSP cards must be run on
fast PCs.  

> I’m looking for a telephony card which does a reasonable amount of
> processing on-board so that the PC isn’t overstretched or interrupted
> too often (it will be going in a Via EPIA system, which has one
> physical PCI slot with a riser that has to accommodate a WLAN card
> too, so it *has* to share an interrupt). I’m a bit concerned from what
> I’ve read that the TDM400P might be fairly unintelligent, leave most
> work to the PC, and interrupt it a lot.

If you want a card that does a lot of processing onboard then don't look
at Digium cards.  However, most people do not need the card to do the
processing on the card.

-- 
          Eric Wieling * BTEL Consulting * 504-899-1387 x2111
"In a related story, the IRS has recently ruled that the cost of Windows
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