LDAP Referrals and Scalability!
nReferrals already used in HEP address book.
nAll LDAP v3.x clients support referrals. (Netscape, Outlook etc.)
nReferral returns to client the address of another LDAP server to contact to fetch data.
nCompletely transparent to user. (Sees single directory not concerned with multiple servers)
nPotentially scalable to millions of objects on dozens of servers.. Searches made in parallel.