You can select Do Not Disturb to prevent the phone ringing on incoming calls.
Enabling or Disabling
To enable Do Not Disturb:
Press Do Not Disturb on the right side of the phone.
A flashing icon and text on the graphic display indicate that Do Not Disturb is enabled.
(also a flashing "X" displays next to the line indicator on multiple lines.)
Calls received while Do Not Disturb is enabled are logged in the Missed
To disable Do Not Disturb:
Press Do Not Disturb again.
If multiple lines are configured on your phone, Do Not Disturb can be set on a line-by-line basis if the feature was enabled by your system administrator. When Do Not Disturb is enabled for a particular line, a flashing “X” displays beside the line indicator (see illustration above).