active directory - kerberos realms

From: barabba (barabba72_at_hotmail.com)
Date: 05/14/04 

Date: 14 May 2004 15:52:13 -0700

Hi all,

we all know that Active Directory uses Kerberos for a number of
things.
We also all know that all Domain Controllers run Kerberos by default.

However, I read in a MS book that it is possible to use third pary
Kerberos service instead of the native Kerberos supplied by DCs.
Is this true ?
Does anybody have any more details about this ?

Thanks,
Bar