Best Directory Server to use

["Nalla, Suneetha R (Suneetha) *CTR*" <Suneetha.Nalla@ons.octel.com>]

Hi,

Can any one please tell me which one is the best Directory server to use. In
terms of scalability, extensibility and reliability.   Which one is the
best, we will be having atleast 3 to 4 million subscriber records. Which
LDAP Directory server is good in performance and support and cost wise. 
Is there a place where I can get comparisons between different directory
servers performance and how many entries they can support etc.

Thanks for your help.

Suneetha.
nalla@lucent.com