asterisk users - Apr 2004 - Asterisk dimensioning (IVR, mass calling)

Hi,

I presently have 6 PRIs of IVR traffic that I am planning to migrate from
Dialogic on SCO-Unix to Digium-Asterisk on Debian. Here is the general
description of the traffic in question :

- IVR system, 138 PRI channels (6 PRIs, multiple D-channel)
- Some traffic from TV ads, so all traffic typically arrives within a few
seconds
- Up to 12-15 simul. outbound (external) conferencing calls for customer
service
- No internal phones
- Several HTTPS transactions per minute
- MySQL queries (to separate server)
- Want do drop minimum of calls, mostly 900 services

I am assuming the following things, performance-wise :

- Since I will be recording to and playing back from ?-law, which is the
format used by PRI in North America, I will require no codec translation and
that should be the easiest on the CPU (right?).

- I will need no echo cancellation since I am exclusively on PRI (right?).

If I rely on previous posts, mainly from Scott Stingel and Azher Amin, I
won't be able to put all this in a single server. I would instead have 2-3
servers (ex. Xeon bi-proc.) with 2-3 PRIs each, and NFS for dynamic content
(recordings from callers).

Does this sound realistic? Is it too risky to go with Asterisk with such a
set-up?

Thanks a lot for your help,

Yves Chouinard
Vox-Tel