Caller ID lets you see the calling party's phone number (and name if available) before answering a call. A special display device located on or next to your phone is required to allow you to view the calling number.
How to Use:
When you receive a call, wait until your telephone completes the first ringing signal. The telephone number calling will automatically appear on your display screen.
For Caller ID to work, all telephone companies and carrier networks transporting the call must be able to understand Calling Number technology.
Does not work on numbers appearing as "private" or "unknown."