My 7/26/09 Missoulian column
In the 1960s, before the modern Internet – but at a time computers were beginning to be used widely in education and government – many researchers found they needed to be able to communicate via computers in more efficient ways.
At the time, a scientist in California would use a computer to do some work on a system in New York, and then have to disconnect and move to another computer in the same office in order to be able to access a computer in Texas.
That’s because computer systems were limited by simple, direct cable connections. Wouldn’t it be nice if all computers could be connected – or networked as we say now – to all other computers, all the time? We take that for granted, but in the 1960s, that kind of networking over the whole country (or world) was a new concept.
So, in the late 1960s, ARPANET (Advanced Research Projects Agency Network) came up with the concept of a standard way in which computers could talk to each other on a network that could cover the entire country without the need for every computer to be wired by cable to every other computer.
That was called packet switching, and it remains the basic form of communication of today’s Internet.
Packet switching protocols take an e-mail or a Web page and break it into hundreds or sometimes thousands of pieces – or packets – which are all transmitted independently over the network.
Those packets traverse the Internet via all the computers and hardware involved, following the path of least traffic and congestion, to be reassembled at the destination computer server.
Packet switching is something like mailing a bunch of postcards with one sentence on each, rather than a single long letter. The postcards go every which way until they are reassembled at the destination computer into a full message. Of course, each packet has hidden routing information in it, so packets don’t go astray.
Any and all computers can pass along packets for other computers, and it helps – not hinders – the network when so many millions of computer servers and routers are attached to today’s Internet.
Packet switching works hand in hand with the way the Internet is wired, so the width and breadth of the connectivity of the Internet actually helps packet switching to work well; and packet switching couldn’t work very well without all those millions of computers connected.