>Avoiding mismatched codecs goes a long way (ie Asterisk doesn't need to
>transcode).
I use a quad Xeon 700, supporting ~200 users w/ > 30 PSTN calls and ~ 40 SIP
& ~30 IAX calls on the box pretty much continuous, 16 hours a day, 7 days a
week. Looking at 'top' right now w/ 41 PSTN calls I'm seeing ~5% on
CPU 1
and the rest hovering at about 0.2%. Because of affinity tricks any CPU
spikes that happen because it is using mime-construct to email a fax or me
running a MySql query happen on the other 3 CPU's and leave CPU1 bound to
Asterisk alone.
CPU use is so low because codecs on the LAN are native to the PSTN, so
there's no transcoding. This is the key.
As to why I would use such an old machine? Hey, it's a NetFinity, it'll
never die and has redundancy up the wazoo. Also, two independent PCI busses
with good throughput. I don't have to worry much about PCI bus contention,
since the TDM cards are by themselves on their own bus. NetFinity's are $400
on Ebay, so I've bought a couple more as spares and a dev machine.
CPU is overrated, (and in fact, irrelevant) when your config is planned out
throughly
hth
