... :Supporting many applications such as call forwarding, caller ID, DND, busy tone, conference with IPPBX and Fax over ... featuresSupport Call forwarding, Call waiting, Call display etc standard voice service and Busy tone, Fax over IP, Three-way conference . ... ModeTelephony FeaturesCaller ID display or block, Call waiting, Blind or attended call transfer, Call forward, Do not disturbQosDiff Serve, TOS ...