[Asterisk-Users] Re:How many TDM22P Card can be used on the same PC ?

[kalezade at boun.edu.tr]

Quoting Eric Wieling aka ManxPower <eric at fnords.org>:

> kalezade at boun.edu.tr wrote:
> > Thank you W, asking differently:
> > 
> > (Suppose) I have a very reliable hardware,motherboard,power
> > supply,bios,kernel,configuration, I have reliable and fast everything.
> > 
> > Now what is the maximum number of FXO/FXS modules? What does it depend in
> > asterisk/tdm cards now?
> 
> Why are you so desperate for TDM400P cards?  Don't put more than three 
> Digium cards in one box.  IRQ shareing is one of the problems.  There is 
> also the problem that each card generates 1,000 interrupts per second. 
> If you want more than 8 or 12 ports then get a T-1 card and a Channel 
> Bank.  The channel bank will convert the T-1 channels to/from Asterisk 
> into analog ports for you.

Because 800$<2000$ (interms of hardware).
(For 12 Ports: The min. price of T1(500$)+channel bank($1,500)=2000$.
While the min. price of 3 TDM400P with 24 modules is just=800$.
Your solution is still 400$ more expensive for 24 ports.)

You say that each card generates an interrupt in every 1ms.
So for 6 cards, each card needs to be processed atleast in
166usec(1ms/6) in their interrupt_routine. Is it teoritically impossible on a
perfect configuration/system?

Thanks.
bdm.