Where's Laz when you need him.
Or the vanity post police?
That’s how dial-up works. If you are on the phone, people calling you get either 1) a busy signal, 2) voice mail or 3) a ringing tone awaiting your call-waiting reply. If you are on a dial-up modem and your phone has call-waiting, you get a “beep” that causes your modem to drop the carrier. Your phone can’t ring in any of the cases if you are on the line, hence the poster is a dummy.