Our company currently has a bunch of NEC DTU16D phones. I am not sure if they are RJ-11 jacks? Maybe I should make a post over on the NEC forum? I want to see if they will work with this Cisco.

Anyway, for the most part they work fine, so we don't want to buy new phones if we don't have to. Our NEC voicemail system died many years ago, so we've been using them as regular phones for a few years now. Problem is phone service is expensive and VOIP looks like it might be a good way to go.

Do they make any ATA/gateway devices that will handle more than 8 devices? If not, can I use two SAP 8000's together?

I have 13 phones in the office and one fax machine, not that I need them all, but we'd like to keep them all connected if possible.