OID value: 1.2.840.113522.214.171.1241
The LDAP_CAP_ACTIVE_DIRECTORY_LDAP_INTEG_OID, which is defined as "1.2.840.1135126.96.36.1991", indicates that the LDAP server is capable of doing signing and sealing on an NTLM authenticated connection, and that the server is capable of performing subsequent binds on a signed or sealed connection. All Windows Server 2003 servers, and Windwos 2000 servers with Service Pack 3 or later will have this OID in the supportedCapabilities attribute.
URL for further info: http://msdn.microsoft.com/library/default.asp?url=/library/en-us/netdir/ldap/ldap_cap_active_directory_ldap_integ_oid.asp
See also the OID Repository website reference for 1.2.840.1135188.8.131.521