Oracle mentions the ability to connect to their LDAP server - the Oracle Internet Directory http://download.oracle.com/docs/cd/B19306_01/network.102/b14267/olsoid.htm. Can Oracle Label Security be configured with an alternative LDAP server such as Active Directory?
Not that easy. Oracle is another big gorilla in the room: they don't publish ldap schemas used in many oracle components. Some times they create hooks for their OID within Oracle software, the way MS does with their AD.
if you know the schemas used in Oracle OID and the seed data they use, you can load those schemas and the data in whatever ldap server you have, and connect it.