The nine-digit Social Security Number is holding strong after 73 years. The 10-digit phone number is six decades old and counting. But the Internet will soon outlive its equivalent numbering system for identifying Web surfers and the sites they visit, which could have disruptive and costly consequences for life online.
As originally designed, Internet Protocol addresses contained 32 bits, represented in four sets of numbers from 0 to 255. There are 4.3 billion different possible combinations, which seemed like plenty to Vint Cerf, who helped develop the IP standards in the late 1970s.
“It was an experiment with an uncertain outcome,” Mr. Cerf, now chief Internet evangelist for Google, says of the Internet. Some other online pioneers argued for 128 bits, but they lost out. “I couldn’t imagine arguing that we needed 340 trillion trillion trillion addresses to carry out an experiment,” Mr. Cerf says.
Social Security numbers should also last well into the later part of this century, according to Social Security Administration spokeswoman Cynthia W. Edwards. The agency has assigned about 450 million numbers, including 5.8 million last year, but nearly a billion are possible — not quite a billion because some numbers, including those that start with 666, aren’t allowed.
Wonder why they don’t let people volunteer to take them? Sure would be easier to remember…
This has been a long time coming; the IPv6 (128-bit) protocol is more than ten years old now, and is very little used in practice. An advantage of this long standardization-without-use is that all current operating systems (the underlying program that drives your computer. Windows or Mac OSX or Linux, mostly) fully support IPv6 addressing already.
The “running out of addresses” problem is longstanding; we’ve been just about to run out of them every year for a decade now. But new net configurations — private networks behind firewalls, communicating with the Internet through a single gateway for hundreds of machines — have put off the problem.
Eventually, though, when your cell phone and your TV set (and probably your toaster) must all have their own Internet addresses, we’ll have to switch to IPv6 addressing. But you won’t even notice it.