[Asterisk-Users] IVR and db

[Jean-Michel Hiver]

Serge Schumacher a écrit :

>Thnx for the fast reply,
>
>What does tanscoding mean ?
>  
>
It means translating from one codec to another, typically g.729 -> 
g.711. You mostly need to worry about it if you're doing VoIP.

>I also think that the calls are not the problem but playing about 120 voice
>files on 240 channels simoultanously ??
>  
>
I am not sure to understand your question. Why on earth do you need 240 
channels for 1,000 calls an hour? How long is each call projected to be?

>Cluster ? DNS ? Anyhow the voices playback can only be done on the maschine
>having the E1 cards connected I suppose ?
>  
>
Well, you could have a dedicated CPE gateway and do everything through 
IP. Considering it's a "one time" survey, I would argue it would be 
faster and cheaper to have a toll free DID forwared from NuFone to your 
asterisk box - especially if you're prototyping.

5,000 employees survey = 5,000 phones calls, 5 minutes each, at 0.02 per 
minute, comes to $500 plus bandwith costs. Compare that with the price 
of a PRI, including PRI cards and such...

If you go for PRI lines, then you don't even need to cluster - I was 
thinking "VoIP setup" there. Just have 1 PC per E1 and a common database 
server, it should work fine. I do not think Asterisk will have any 
issues handling 30 simultaneous calls (i.e. 1 E1) - even with AGI 
processing - on decent PC hardware.

How many channels are you planning for? From what you said I would plan 
for 2 E1s. Provided you use these newer cards with hardware echo cancel, 
and don't do fancy transcoding, I would assume that you might not even 
need multiple boxes since the CPU usage shouldn't be so high...

According to the voip-info.org litterature, the two CPU hungry things are:

1/ Transcoding
2/ Echo cancellation

So... with decent hardware I would argue you should be just fine... no 
warranties given though. If you want to be sure that your system is 
correctly dimensioned first time you probably should write down some 
specs and ask Digium to sell you a turn key system which will Just Work...

Cheers,
Jean-Michel.