Saturday, October 04, 2008

Doom and disaster!

The end of the world is nigh!

I read in the paper the other day that it is being forecast that in two years' time we shall have run out of internet addresses. Just imagine, if nobody else could sign up for email!

I remember, not long after getting a computer, asking naively if cyberspace could ever become full up with the internet and the web; I was more or less laughed at. So if we are not going to run short of cyberspace, what is it that will be in short supply when we run out of internet addresses? Do I really want to know? Could I understand if I was told? Explanations in words of three syllables max please!

For those who do wish to understand, here are a couple of links to articles in the Times and the Guardian.


Lee said...

How does that work? Surely I could be Don't you just keep adding numbers after your name until you get a 'free' address?

Judith said...

I couldn't possibly say, Lee, but I am putting a couple of links into the blog for those who really want to understand it - which I have to admit, I don't! Not as long as someone finds a way for me to keep going, and it seems that's \lready on the cards.

KeithD said...

It's not e-mail addresses that are close to capacity but internet addresses, such as Whatnot itself can allocate as many e-mail addresses at whatnot as its software can handle, because all the Internet uses is the "" part to deliver e-mail to whatnot.

I can't explain it without being a little technical, unfortunately.

Although we almost always see site addresses as names, the Internet actually uses numerical IP (Internet protocol) addresses, which are usually shown as four decimal numbers separated by periods. For example, will take you to the US Google site in English (which you won't otherwise be able to get to from the UK even if you specify because Google will redirect you to Conversion between the typed or displayed name and the IP address is transparent to users and is done through one of the DNS (domain name service) sites, such as

Since computers work in zeroes and ones (binary coding), each of those four numbers is the decimal representation of a binary number. The current internet protocol (IPv4) specifies that the maximum for each of those numbers is 255, which together with zero gives 256 possibles (which is 2 to the power of 8, ie 2*2*2*2*2*2*2*2). So we have a limit of 256*256*256*256 (which is 2 to the power of 32) possible addresses, which is only 4,294,967,296. We've almost run out of them, and some estimates say we will do so in the next two years.

The current solution is to move to IPv6, under which EACH of the four ELEMENTS of the address will have a limit of 4,294,967,296. That allows for roughly 50,000 million-million-million-million Internet addresses for each of the 6.5 billion people alive today (says Wikipedia). No one expects them to be sued, but the extra flexibility will permit other improvements. Because IPv6 brings a few other changes too, so we will have to move from v4 to v6 over a few years during which both protocols will coexist.

It may help to compare the change to the frequent rejigging of London telephone numbers in the UK, each designed to extend the range of possible numbers. So for London we moved from letters for exchanges to numbers; then added a 01 prefix, changed that to 071 and 081, then to 0171 and 0181, all followed by seven digits; then moved to the current 020 followed by eight digits.

Judith said...
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Judith said...

Well, I asked - and most of that I can follow, except that I am lost when it comes to binary coding. But I think I grasp the principle of the difference between IPv4 and IPv6. I note though that you didn't meet my requirement for an explanation in words of three syllables max - I shall have to deduct marks for that Keith! ~;)

Lucy said...

I thought perhaps it meant there was no longer enough room in those great big server computer things which they keep in turf roofed buildings the size of many football pitches in palces like Iceland. I'm not sure I trust Iceland any more to look after my blog as they haven't done very well with the world's money, but I suppose we don't really have a choice...

Anyway, if it's just a question of digits that can be adjusted, that seems to be OK for the moment! Thanks to Keith for explaining.