The PBX assigns the following default extension numbers to system services. These system extension numbers are reserved and cannot be used for creating new extensions:
Call Announcement Service: 555
To modify this number, navigate to Advanced Services > Automatic Callback.
Call Park Service: 666
To change this number, go to Advanced Services > Call Park and select Global Settings.
Voicemail Service: 777
To update this number, navigate to Advanced > Voicemail.
Call Monitor Service: 888
To adjust this number, go to Contact Center > Monitor Service.
Ensure these numbers remain unused when creating new extensions to avoid conflicts with system services.
