Multiple AD's and domains?

Hi Guys, I have an upcoming project where the setup is going to be something along the following: Client logs in using their username/password for domain FreeRadius authenticates the user against the AD server for that domain There will be clients using the service from MULTIPLE different AD domains with multiple different AD servers. The freeRadius version will be built from the latest stable source. Now, the stock standard way of authenticating against AD is using samba, joining the domain, and using NTLM Auth. Since I have multiple AD domains, how would this best be handled? I know that PHP is capable of using LDAP to authenticate against an AD server. Can freeRadius also do this? How, or why not? Thanks, ~Justin