Stop ringing at certian phones when outside calls come in.

Http://dstech1.com/programming-line-ringing/


Partner, all releases. Examples
Receptionist Call Routing. If you want calls to be answered by the receptionist first, set the lines at the receptionist's extension to Immediate Ring and the lines at the users' extensions to No Ring. (This is the factory setting)
Receptionist Backup. If you want all calls on a line to ring directly at users' extensions -with the receptionist providing backup -set the line at the users' extensions to Immediate Ring. Then set the line (or lines) at the receptionist's extension to Delayed Ring. An incoming call that is not answered by a user within 20 seconds will also ring at the receptionist's extension.
Programming
To change the way outside lines or pools ring at an extension:

1. Press [ Feature ] [ 0 ] [ 0 ] [ System Program ] [ System Program ] [ Central Tel Program ].
2. Enter the number of the extension to be programmed for Line Ringing. The green lights next to the line or pool buttons on the phone show the current Line Ringing settings for all lines assigned to the extension. (If a line is not assigned to a button, the green light next to the button is off.) The following ringing options can be shown by the green light next to the line button.
   • Immediate Ring - on steady
   • Delayed Ring - flashes slowly
   • No Ring - flutters quickly
3. To change Line Ringing for any line, press the line or pool button until the button light shows the correct setting (the setting for the currently selected line or pool also appears on the display).
4. Continue programming or exit programming mode.