CUC 10.X supports LDAP integration with several widely used LDAP directories systems, including the following:
A. Microsoft Active Directory 2000, 2003 and 2008 (support for AD 2012 only in CUCM 10.x and later)
Microsoft Active Directory Application Mode 2003 Microsoft Lightweight Directory Services 2008 iPlanet Directory Server 5.1 Sun ONE Directory
Server (5.2, 6.x)
Open LDAP (2.3.39, 2.4)
And what about Open LDAP (2.3.39, 2.4) which you mentioned to?
From what I searched I think Microsoft Active Directory 2000 is not supported and the correct answer is:
B. Microsoft Active Directory Application Mode 2003
Table 5: LDAP Directories Supported for Synchronization and Authentication
– Microsoft Active Directory 2016 Lightweight Directory Services: Yes
-Microsoft Active Directory 2016: Yes
– Microsoft Active Directory 2012 Lightweight Directory Services: Yes
– Microsoft Active Directory 2012 and Active Directory 2012 R2: Yes
– Microsoft Active Directory 2008 and Active Directory 2008 R2: Yes
– Microsoft Active Directory 2008 Lightweight Directory Services: Yes
– Microsoft Active Directory 2003: Yes
– Microsoft Active Directory Application Mode (Windows Server 2003 and Windows XP Professional): Yes
– OpenLDAP 2.3.39 and 2.4: Yes
– Sun iPlanet Directory Server 5.1 and later: No
– Oracle Directory Server Enterprise Edition 11g and later (formerly Sun ONE Directory Server): No
Source: https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/connection/10x/requirements/10xcucsysreqs.html
On System Requirements for Cisco Unity Connection Release 10.x
http://vceguide.com/cuc-10-x-supports-ldap-integration-with-several-widely-used-ldap-directories-systems-including-the-following/
state the list of supported LDAP systems
Microsoft Active Directory 2012 and Active Directory 2012 R2
Microsoft Active Directory 2008 and Active Directory 2008 R2
Microsoft Active Directory 2008 Lightweight Directory Services
Microsoft Active Directory 2003
Microsoft Active Directory Application Mode (Windows Server 2003 and Windows XP Professional)
OpenLDAP 2.3.39 and 2.4
Sun iPlanet Directory Server 5.1 and later
Oracle Directory Server Enterprise Edition 11g and later (formerly Sun ONE Directory Server)