I am trying to restructure Active Directory and our many Domain controllers to prepare for Exchange 2007 and to streamline replication from the previous Admin. I am getting mixed ideas on how our environment should be setup...Please review and provide any insight to this topology
9 Domain Controllers
Each location is connected to the Data Center by a T1
Each location has a Domain Controller
All 9 Domain Controllers are Global Catalog Servers
Some Microsoft tech reps tell me to remove all sites and make just one big site with all the subnets tied to it in AD. Demote all domain controllers except the PDC and one backup. Turn all servers at each site to just file servers to host files for each campus.
I want to make sure that if a T1 goes down the users at the campus that have a downed T1 can still log in with cached credentials or maybe another way and work on items that are hosted on the campus file server. Obviously services that are hosted from the data center like email, and internet will be down, but that is OK.