We currently use low Dell desktops for Asterisk phone systems for 5-10 users. I noticed that I could save a little bit of set up time and save a little on costs if I use IBM/Lenovo laptops. It would eliminate the need for buying an expensive battery backup, PCI serial cards (for the battery backup), and it would save the expense of a keyboard, mouse, and monitor if for some reason we would need to directly access the phone system.
I am curious, what problems would we run into using a laptop for a commercial installation of a phone system? The phone system would interface with the phone company via SIP connection.
Also, if I have a company that is interested in using an older laptop (IBM T40 or T42), how would I test if this equipment can handle 5-10 users, etc?