See Whos Calling, Even if Youre Already on the Phone Weve all become accustomed to Caller ID and its ability to let us see whos calling before we answer the phone. Then theres call waiting, a beep letting us know theres another call coming in. But until now, you wouldnt know who was beeping in unless you answered it. With Call Waiting Caller ID1 you get the best of both worlds. Now when you get a beep, you can see whos calling before you answer. But well leave that decision up to you!