YOU CANNOT MAKE THIS CHANGE WHILE ON A CALL
To access the web interface for your phone, you will need your phone's IP address. To find your phone’s IP address, simply press the OK key on the phone.
Note: This will take you to Voicemail if you currently have a new Voicemail Message. Be sure and clear all Voicemail Messages beforehand.
In your web browser, go to the IP address of your phone. In this example, the address is: http://192.168.0.221
You'll then be prompted to log in.