The Domino LDAP server does not support RFC 3928, so the Domino LDAP server cannot be used as the LDAP server for a client wanting to use the LDAP Persistent Search features.
RFC 3928 defines an LDAP Client Update Protocol, otherwise known as LCUP or Persistent Search. This protocol allows an LDAP client to create a persistent connection to the LDAP server for the purpose of synchronizing the client with a specific directory and having the LDAP server notify the client of directory changes so the client can have up-to-date information. For additional information, refer to the technote titled "Which RFCs Does LDAP Support? (#1199685), and to the Domino Administrator Help topic "RFCs supported by the LDAP service".