1188 Matrix PRASAR UCS System Manual
When the below mentioned features are accessed the call will always be an Audio call:
• When a user access Voicemail, initiate an Emergency Conference or make an Intercom request.
• Features where-in the system initiates the call such as ACB Return call, Auto Redial Return call, Alarm
call, etc.
• To dial Flash, make sure your IP Phone supports Flash dialing.
• You can use #2, if your IP Phone does not support Flash dialing.