System requirements for a PBX

can you please suggest me the hardware requirements (processor, memory) for the following scenarios…

case 1:- (4032 PABX)
Asterisk free version should be installed with TDM400P wild card with 4 FXO modules to handle 4 direct lines, and 32 SIP extensions should be handle, simultanously maybe 10 calls…

case2:- (208 PABX)
Asterisk free version should be installed with TDM400P wild card with 2 FXO modules to handle 2 direct lines, and 8 SIP extensions should be handle, simultanously maybe 4 calls…

well, for the first case, we are running a dell optiplex with a 3GHz pentium 4, 1 GB of RAM, and it runs like a champ. we spike into the 50% CPU usage arena occasionally, and that is partially because we’re running Vicidial on this box, which increases load quite a bit. we have about 12 users on the machine concurrently, and all will be on active calls at once.

the second instance you could get by with a 1.4GHz CPU or greater, i would think…but as cheap as desktops are, I’d start with one of those, and use some sort of SIP stress testing tool (astertest comes to mind, although I haven’t used it) to see what your load stats are.

just make sure to optimize your linux install for Asterisk - don’t install what you won’t use.