File server / BDC - licencing

[dbrown]

As a result of replacing an admin server, I have a spare server machine which actually is better the the DC on the school NW. Therfore I would like to remove it from the admin domain and put it on the school domain, as a file server at least - possibly as a BDC. Since it is better in every way than the current PDC, I suppose the more functions I transfer the better.

Question: what do I need to buy in the way of licences? It currently has 10 CALs just for SMT & admin staff: the school server has 150 per machine CALs.
Never having had more than 1 server on a domain, I've never had to buy more than 1 CAL per client. For domains with multiple servers, does one need multiple CALs per client?

School PDc is 2003 Server, as is the redundant admin server. (The new admin server will be 2008 Server and will have new CALs for that.)

[plexer]

Depends on your licensing method wether you have set it to per seat or per user.

Ben