Is there anything more irritating than getting a busy signal? The other day I called my friend, Louise, and the line was engaged. I think the last time this happened it was 1985. Naturally, I assumed something awful had happened. Maybe someone had broken in to her house and cut the line. Maybe she was dusting and accidently knocked the phone off the hook.

It seemed incomprehensible that in this day and age, a busy signal would not be the result of some horrible mishap or accident. Unless you're 80 years old, there's no excuse for not having call-waiting.

After several attempts, I got through. Turns out, she wasn't dead. She was talking. Once I discovered the absence of call-waiting was intentional, I expressed my frustration. Her defence? "It's honest. You know what a busy signal says? I'm busy."

I admit I never thought of it like that. But that's because I'm part of the human race. Why not just get rid of the phone altogether and write letters? That's honest too. It says: I'm not interested in how long it takes you to reach me.

As far as I'm concerned, call-waiting is a necessity. Like breathing and drinking coffee. It's impossible to imagine life without it.

Plus, the beauty of it is, you can ignore it. You have a choice. If there's someone you don't want to talk to - you don't respond. For the person calling, they get it - you're on another call. If you were out, the voice mail would answer. These rules are understood. A busy signal is nothing but grief.

Of course there's an etiquette with call-waiting that makes me nervous. There's a hierarchy. If I'm in the middle of a conversation and the person I'm talking to gets a call coming in, I'll have to wait to find out if I'm going to be rejected for a more important call. Usually they'll return and announce: "I have to take this." And then they add: "It's work-related."

That's the polite way to dump someone. You say it's a work call - or long distance. Saying it's a parent or a doctor works too. No one will challenge it.

Not that I haven't tried. A few weeks ago a friend returned to the line and said she had to take the other call. So I said, "Why? Who is it?"

There was a pause. Then she said, "It's informational."

What does that mean? It means she doesn't want to talk with me. No-one will ever come back and say: "I have to take this other call because they're more important than you."

I know some people get annoyed with call-waiting but I never do. Waiting on hold feels like an acceptable time out. I get credit for being polite and patient without having to do anything taxing - like listening to someone talk.

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