Fax throughput for incoming faxes

I’m trying to determine the number of lines necessary to handle a particular incoming fax volume.

Here’s the basic info: Peak hour: 120 faxes (average of 4 pages per fax). Analog fax card will be used on the server (Intel/Dialogic CPi 400). The processor runs at 1.8 GHZ with 512MB memory. The software will be RightFax.

Volume is expected to increase (of course…)