I have an IP Telephone (i.e. 1603, 9640, 9630, …). How I can I log out to prevent unauthorized use of my telephone during my absence ?

If you have an IP phone, there is an option that allows you to log in and out of your telephone, while maintaining your preferences and information.
To log-in to your telephone:

1. At the initial screen when it prompts you for your extension, enter your extension.
2. Press on Enter or OK or #.
3. Enter your password.
4. Press on Enter or OK or #.          
NOTE: You are logged into the phone. 

To log-out of your telephone:
1. Press on the Avaya Menu.
2. Select Log Out.
3. Press on Log Out or OK or #.