Complete integration documentation for additional reference, here.
Depending on existing settings, the PBX link integration may stop working. The PBX link is what DuVoice uses to forward name and COS updates to the IP Office.
This is not supported by Avaya. These DLL files are updated versions of those in the Avaya SDK distributed with DV2000 distribution to perform name changes. Avaya has never updated their SDK distribution since it's release.
It is not known if the DLL's provided via IP Office Manager are backwards compatible and therefore you should always use the version of IP Office Manager you use to manage your IP Office.
This procedure must be performed each time the DV2000 is updated/upgraded.