Journey Of An E-mail
by John Dyson
DOUG AND JULIE Young raise dandie dinmont terriers. They also publish a newsletter for fellow lovers of the breed. Not too long ago they wanted a photo of Mr D, our family pet.
I could have sent the photo by ordinary mail, but that would have taken at least four days. Instead, sitting down at the computer in my den overlooking London's River Thames, I sent an e-mail. I typed an address, young@montizard.com, composed a short message, then attached a photo I'd scanned into my PC. I then clicked on Send. Mr D instantly vanished from my screen on the way to Ohio.
Along with more than 150 million others around the world, I use e-mail all the time and can't imagine living without it. How it actually works, of course, was a mystery. So one day I decided to find out. Mounting my bicycle, I pedalled off to follow my dog through cyberspace.
Chopped Into bits. The first stop was a brick office plaza between a canal and an elevated highway in Brentford, West London. This was one of the homes of Cable & Wireless, the company that connects my computer to the Internet by telephone lines. Escorted through security checks and card-swipe doors, I entered a brightly lit, windowless room with rows of fridge-size metal cabinets called racks, containing computers the size of TV sets, each costing as much as a car. In an adjoining control room, engineers, some of whom were wearing earrings, were monitoring rows of complicated numbers on video screens. As the racks tend to look the same, engineers give them names. "This is Marvin," said Jason Semple, pointing to one. "He's your postbox."
A burly 27-year-old, Semple hooked a finger over the spine of what looked like one of scores of video cassettes on a shelf. He slid out a circuit board glittering with tiny gold wires and silver connectors.
"When your computer dials our I number, it's answered by one of these I modems," Semple explained. "It checks your name and password with another computer, then asks what you want." My computer had replied, "I've got mail."
Next, Mr D was fed into a "mail server" a bunch of computers filling five racks. One read my e-mail's destination and checked another, which stored Internet addresses like a gigantic phone directory.
The Cable & Wireless directory could do ten look-ups a second. It didn't find montizard.com, so it asked a bigger directory, storing ten million addresses in Europe and Africa. That didn't work either, so it asked one of 13 core directories (ten in the United States, two in Europe, one in Japan) holding every Internet address in the world.
Back came the answer: "Send mail to BuckeyeNet." This is the company that connects the Youngs to the Internet. Buck- eyeNet's Internet address - 209.41.2.152 -was clipped like a dog tag to Mr D's collar. Next, something bizarre happened. Imagine a postal clerk who chops your letter into little bits and puts them into separate envelopes. This is done to every e-mail. All the bits and bytes representing Mr D were instantly divided between about 120 packets. Everyone was stamped with BuckeyeNet's address, plus my own address, so that the jig-saw puzzle could be reassembled at the other end.
But they didn't go all at once. Instead, a single packet was sent off like a scout car, to knock on the door of BuckeyeNet, say hello and make a connection. The first stop was a gateway router, which would help the scout car find the way.
Kids with torches. Picture the Internet as 65,000 interstate highways crisscrossing the globe and connected to smaller roads and streets. Like a policeman with a walkie-talkie on every crossroad, the router learns the fastest way to get an e-mail to its destination. It knows all the routes and, by talking to other "cops" down the road every 30 seconds, it discovers where the delays are say, heavy telephone traffic or a broken cable. A Cable & Wireless router sent Mr D's hello packet across London to the company's transmission centre in Docklands, where another router fed it into the stream of e-mail packets heading for the westerly tip of Cornwall, the nearest part of England to America.
All this happened in four milliseconds - like a lightning flash.
I took a decidedly slower train to Cornwall and went to Porthcurno, a cliff-top village. There, in a barnsize room, is the base station of the transadantic Gemini cable. Take a hair-thin fibre of glass, wrap it in a protective jacket, then incorporate it with others in a rubbery protective tube. This is fibre-optic cable, known in the trade as pipe. A flashing laser at one end fires digital on/off signals along the fibre. At about 193,000 kilometres a second -more than half the speed of light - they zip to the other end.
"It's the high-tech equivalent of two kids signalling each other with torches," says Dave Shirt, operations director. With pretty quick fingers, I'd say the lasers flash 10 billion times a second.
More gold earrings. Mr D's packet next jostled for elbow room with a torrent of transatlantic electronic traffic - equivalent to 100,000 closely typed pages every second, or 400,000 simultaneous phone calls. Think that's a lot? At present six parallel lanes of traffic hurtle along every glass fibre. Newly laid cables will soon have 128 lanes, preparing for the explosion of Internet traffic when every movie ever made could be available online.
I returned to London, hopped on a plane to New York and rented a car, then picked up Mr D's trail again on a long, flat beach in Manasquan, New Jersey, where the Gemini cable comes ashore. Next the e-mail zipped along poles and beside railway tracks before flashing into 60 Hudson Street, in central Manhattan. Time taken from London: approximately 40 milli-seconds, or one-tenth of a blink of the eye. This 22-floor art-deco building is a "telco hotel" where phone companies own or rent space for equipment so they can connect to one another more easily. The scout packet was switched into high-capacity "fat pipes" crossing the United States. It also hit what engineers call ATM - asynchronous transfer mode.
At this point Mr D was diced yet again into dozens of identically sized i cells that flashed through the back of a telephone exchange in West Orange, New Jersey, just west of New York.
But from there the cells had a really wild ride, zipping through pipe beside railway tracks, into and out of Philadelphia, up the Ohio Valley, through Cleveland and into another telephone exchange at Willow Springs, outside Chicago. Here the bits came together, and the original packet was restored. It all took a fraction of a second. Barely pausing for a breath, so to speak, the scout packet next raced through Chicago and Detroit, before landing in a building in Columbus, Ohio - headquarters of Fibre Network Solutions. There I met the company's co-founder, Kyle Bacon, a laid-back 27-year-old wearing two gold earrings.
Bacon, who used to cut classes to work on his university's computer system, helped set up a network that controls Internet pipes so businesses and industry have to pay the company to open the tap. That was three years ago. Now the company employs 45 people, and Bacon drives a silver BMW whose numberplate reads FAT PIPE. A router in the company switched Mr D into a skinny pipe running direct to the home of BuckeyeNet - then a two-room office with a dirt car park. BuckeyeNet has over 1000 clients and 13 computers. By way of comparison, the biggest Internet-access provider in the world, America Online (AOL), has some 19 million subscribers and servers covering football fields of floor space.
Dressed in shorts and, naturally, sporting a gold earring, Jonathan Sheline, 27, told me he'd set up the company after leaving the army, where he'd served terms in the infantry and counter-intelligence. In just 18 months his net was one of the largest in the town.
Our friends the Youngs are among its clients.
"OK, I'm listening." BuckeyeNet's mail server unwrapped Mr D's scout packet, which carried a message. "Helo," it said. "I'm j.dyson at cwcom.net." "Helo" means hello in a computer language called Simple Mail Transfer Protocol (SMTP). BuckeyeNet's mail server dispatched an acknowledgment to London, which took one-tenth of a second to arrive. Next the two computers negotiated the connection. Their conversation, using codes as well as plain text, went something like this:
Ohio: OK, I'm listening. SMTP is spoken here.
London: I have mail from j.dyson at cwcom.net.
Ohio: Pleased to meet you. London: I've got mail for montizard.com.
Ohio {checking list of clients): OK, I can handle that. London: I'm ready to send data.
Ohio: Start mail input.
From London, five packets hit the road. If any crashed or failed to arrive, the Ohio dispatcher would let London know and they would be sent again. When this bunch arrived, Ohio said: "1 got the first five, give me five more."
Despite all the messages pingponging across the Atlantic, the last bit of Mr D straggled into BuckeyeNet's server less than half a minute after I had originally clicked on Send. For me it had been nine hours in the air, four hours waiting for a connection and an hour-and-a-half in cars. And my luggage was left behind. But Mr D still had to go the last eight kilometres.
When I arrived in their old farmhouse on nearly two hectares outside Rushville, Doug and Julie Young were making breakfast for 35 dogs, 30 ferrets, two llamas and a parrot. Julie had an armful of cans, bowls and milk cartons, diffi- cult to carry because they were all different sizes.
Meanwhile, from a big paper bag, Doug filled a container with pellets of dog food -the perfect metaphor for understanding why e-mails are minced and shredded into packets and cells. Like pellets, they pour more easily and therefore travel much faster. A big, jovial man of 51, Doug uses e-mail to talk with breeders allover the world. When he clicked on Get Mail, his BuckeyeNet server checked his mailbox and forwarded its contents down the phone line. The stream of bits materialised into Mr D gazing imperially out of the screen from his kitchen chair, not a bit rumed after his 6400-kilometre dash.
Thanks to the Reader's Digest - June 2000