Remember those thrilling days of yesteryear, when telephone numbers were made up of 3 or 4 digits? Sometimes, usually for party lines, there was a letter attached -- for instance, 469W, 469J, 469M. Even earlier there were telephone numbers with only 2 digits. Easy to remember those.

Then came 7-digit numbers. Those were traumatic times -- could anyone really remember 7 digits? Well, yes, we could, primarily because the first 2 of those digits were letters rather than numbers (Remember the Glen Miller song Pennsylvania 6-5000, or the Liz Taylor movie Butterfield-8?)

Things got worse. In 1958 the letters were dropped in favor of "all number dialing." Now there was no hint or accompanying word that would help us remember.

And finally, when we learned to dial long distance telephone calls by ourselves, we had to include the appropriate area code. This amounted to 10 digits -- 11 if you count the "1" that preceded it and indicated it was a long distance call. No one, we claimed, could remember all those digits! (Most people didn't notice in those early area code days that the second digit of the area code was either a "1`" or a "0." And that the second digit of an exchange was never a "1" or "0". Or that the "1" and "0" were -- and are -- the only 2 digits without a letter assigned on the telephone dial).

There was some semblance of relief when we were told that the area code didn't have to be dialed if you were calling someone that had the same area code as did you. But sometimes not even that worked. If your particular area ran out of telephone numbers one way of solving the problem was a new, overlay, system. In this case (for instance, the suburbs of Chicago) you have to dial 11 digits to reach the person living next door. To make things even more confusing, in Florida's Tampa/St. Petersburg area, Tampa has an 813 area code and St. Petersburg a 727 area code. You would think that to dial Tampa from St. Petersburg you would have to dial 1-813-xxx-xxxx. Sorry, it doesn't work that way. A rather nasty recorded operator says that the initial "1" should not be dialed, and "Please hang up and dial again."

But finally everything seemed to be under control.

And then along came the Internet, and the World Wide Web, and e-mail. And the need for an immense number of new addresses. As we all know, addresses on the Internet are not numbers, but rather words. So there must be a means for converting the words to numbers, and vice versa. It is almost like the telephone industry's telephone directory, where we look up a name, note the associated address (telephone number) and dial. In the Internet case the translation and dialing are done automatically. But a lot of numbers are needed!

The initial packet switching system (which we described in gory detail in a previous issue) was the fourth revision in the development of the Internet Protocol (hence the name IPv4). Unfortunately the designers grossly underestimated the number of addresses that would be required, and as of the middle of this year -- 2011 -- we are approaching exhaustion.

How many addresses are available in the IPv4 system? Approximately 4,294,967,296. That is, 232.. And that's not enough! Blame it on the rapidly growing number of Internet users, or the laptop computers and smartphones.

Whatever the cause, the last block of numbers was allocated in February, 2011.

So what is to be done?

The answer, hopefully, is IPv6, where the number of available addresses is 2128 (approximately 340 undecillion).

When you get right down to it, the migration we are about to see (implementation of IPv6 is now taking place) is not much different from what we saw as regards telephone numbers.

We need more, more, more.

What is your experience with this? Tell your fellow readers now!