Thesis 61

The necessary addressing scheme already exists.

As we considered earlier, a technology with the ambition to colonize much of the observable world has to offer some provision for addressing the very large number of nodes implied by such an ambition. We've seen that a provision along these lines appears to exist, in the form of something called IPv6, but what exactly does this cryptic little string mean?

In order to fully understand the implications of IPv6, we have to briefly consider what the Internet was supposed to be "for" in the minds of its original designers, engineers named Robert E. Kahn and Vint Cerf. As it turns out, Kahn and Cerf were unusually prescient, and they did not want to limit their creation to one particular use or set of uses. As a result, from the outset it was designed to be as agnostic as possible regarding the purposes and specifications of the devices connected to it, which has made it a particularly brilliant enabling technology.

The standard undergirding communication over the Interneta network layer protocol known, rather sensibly, as Internet Protocol, or IPdoesn't stipulate anything but the rules by which packets of ones and zeroes get switched from one location to another. The model assumes that all the intelligence resides in the devices connected to the network, rather than in the network itself. (The term of art engineers use to describe this philosophy of design is "end to end.") As a result, as these things go, the Internet is simple, robust, all but endlessly extensible, and very, very flexible.

For our purposes, the main point of interest of the current-generation IPversion 4is that it is running out of room. Addresses in IPv4 may be 32 bits long, and the largest number of discrete addresses that it will ever be possible to express in 32 bits turns out to be a little over four billion. This sounds like a comfortably large address space, until you consider that each discrete node of digital functionality ("host") you want to be able to send and receive traffic over the network requires its own address.

The exponential growth of the Internet in all the years since scientists first started sending each other e-mail, and particularly the spike in global traffic following the introduction of the World Wide Web, have swallowed up all of the numeric addresses provided for in the original protocol, many years before its designers thought such a thing possible. It's as if, while building a new settlement in a vast desert, you had somehow begun to run out of street numbersyou can see limitless room for expansion all around you, but it's become practically impossible to build even a single new house because you would no longer be able to distinguish it from all of its neighbors.

This scarcity is one of the stated justifications behind promulgating a new version of IP, version 6. By virtue of extending the length of individual addresses in IPv6 to a generous 128 bits, the address space thus evoked becomes a staggering 2¹²⁸ discrete hostsroughly equivalent to a number that starts with the numeral 3 and continues for 38 zeroes. That works out to 6.5 x 10²³ for every square meter on the surface of the planet. (One commentary on the specification dryly suggests that this "should suffice for the foreseeable future.")

What this means above all is that we no longer need to be parsimonious with IP addresses. They can be broadcast promiscuously, tossed into the world by the bucketload, without diminishing or restricting other possibilities in the slightest. There are quite enough IPv6 addresses that every shoe and stop sign and door and bookshelf and pill in the world can have one of its own, if not several.

The significance of IPv6 to our story is simply that it's a necessary piece of the puzzleif the role of sufficiently capacious addressing scheme wasn't filled by this particular specification, it would have to be by something else. But everyware needs a framework that provides arbitrarily for the communication of anything with anything else, and IPv6 fills that requirement admirably.