With IP Office Release 6 and later, the master base station can obtain directory information direct from the IP Office control unit rather than the system requiring an AIWS unit to do this. This requires the master base station to be able to access the IP Office control unit using TFTP. The directory import is limited to 6000 entries.

Note that enabling directory integration via the master base station disables support for SMS. If both SMS and directory integration are required then an AIWS unit must be used.