Newbie question: Analog?

I recently took over IT admin duties for a small company, and we are trying to downgrade from a fractional digital service to an analog phone system - it is much cheaper and we really don’t use enough to justify the cost of digital.
Anyway, we currently use Polycom Soundpoint IP 501 phones, and an asterisk server. We would like to keep the asterisk server so we can, use the IVR, ring groups, etc; and we would like to be able to use these same phones. I am not sure what is involved in switching to analog telephone service and how it will affect this system - there is tons of documentation for upgrading to digital, but not much on going back. Anyone have any advice or pointers?

You will need a digium card…and use it as a zaptel POTS line…

Hi

Do you have any DIDs on the T1? you may well have, also is the T1 pure voice or is it part data?

I wouldnt go back to alog if I were you, why not check how many lines the supplier will let you go back to, they may well let you drop back to 6 or 8 lines.

Another optionis to port your numbers to an ITSP that supports porting and then use voip.

Ian