asterisk users - Aug 2005 - Re:How many TDM22P Card can be used on thesame PC ?

>>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?
>In theory there isn't much difference between theory and practice.  In 
>practice, there is.
>In other words: you're being advised against this by multiple people.You
can
>heed their advice, or you can spend the $800 and have it fail, and then 
>spend your theoretical $2000 on top of that to get a solution that works,
and
>will work better, and that will scale much better.
>-A.
Thanks but it doesnt answer my question.
>As everyone else has said, you *might* be able to make it work, but it is 
>extremely unlikely. You want to buy a T1 interface and a channel bank.
>Tom
And nobody knows/mentions (in archives) why it will fail on a
"""reliable"""
system.(If you dont know how asterisk handles those cards, you can blame
everything...)

Soner Tari wrote:
>Sorry but to have 24 ports you need 6x TDM cards, which adds up to at least 
>$1900. And for 12 ports (3x TDM cards) at least $950. From where do you 
>purchase the TDM cards?
Sorry.. my calculation mistake..
>I have a system with 12 FXs , 8 FXO, and E1 Card working very well.
>Alex
Alex, if you are talking about TDM400P cards, I will go with TDM400P cards.Other
wise I will go with E1+channel bank. 

BDM

----- End forwarded message -----

On Thursday 18 August 2005 18:08, kalezade@boun.edu.tr
wrote:
> Thanks but it doesnt answer my question.
Yes it does -- It answers your question in the sense of "nobody else has
done
it, it seems everyone else goes for a T1+CB, so how about you try it and 
report back since you don't want to take anyone's advice but rather
insist
that it's theoretically possible.
> And nobody knows/mentions (in archives) why it will fail on a
> """reliable""" system.(If you dont know how
asterisk handles those cards,
> you can blame everything...)
Actually they have.  Interrupt sharing for one.  Interrupt overhead for 
another.  Drivers which are optimized for minimum latency instead of a 
balance between latency and ability to share interrupts and overhead for a 
third.

But again, we aren't saying "yes it works, this is how" so you
pretend not to
hear.  So since you are obviously the smarter of all of us you can ignore our 
experienced answers and go it your own way.  Just be sure not to bitch about 
the shitty cards/software/users list when you respond after spending the 
money on two solutions...  the one which will theoretically work and the one 
which has been shown to work in practise.

-A.

On Aug 18, 2005, at 6:08 PM, kalezade@boun.edu.tr wrote:

[snip]
>> As everyone else has said, you *might* be able to make it work,  
>> but it is
>> extremely unlikely. You want to buy a T1 interface and a channel  
>> bank.
>> Tom
>>
>
> And nobody knows/mentions (in archives) why it will fail on a  
> """reliable"""
> system.(If you dont know how asterisk handles those cards, you can  
> blame
> everything...)
I am more and more convinced that this whole thing is just a troll,  
but here goes anyway:

You are 100% correct. The problem isn't that the cards are so very  
sensitive to interrupt issues that using more than one or two causes  
problems. The problem is that none of the 10,000+ technology  
professionals on this list knows how to build or purchase a  
"""reliable""" system. Maybe you should call the
manufacturer
(Digium) and ask them what they think.

Basically, you have two choices:

1.) Listen to the list members, who are all telling you that, even if  
6 TDM cards might theoretically work, in practice it is damn near  
impossible to make it happen. Moreover, if you do manage to get it  
working because you are such an experienced and amazing  
"""reliable""" system builder, everything will
always have to be 100%
spot-on for it to work.
2.) Buy the six TDM cards, install them, get them working, and prove  
everyone wrong. We certainly aren't infallible, but keep in mine that  
you aren't the first intelligent person to have this idea.

The $64,000 question is, of course, why you would ever want to do it.  
A TDM400B card with 4 FXO ports costs $337.00 from Digium, while a  
TE110P costs $595.00, and a used channel bank costs $1000 or less on  
eBay. $2022.00 > $1595.00, and you would still have a less  
"""reliable""" system. Not to mention that a
system with 6*TDM is no
longer expandable, while a system with a TE110P and a channel bank  
still has PCI slots you can use.

Tom