Cryptonomicon

by Neal Stephenson

  That’s right — in a nicely Pharaonic touch, one of the six ducts going into the ground here is the sole property of President Hosni Mubarak, or (presumably) whoever succeeds him as head of state. It is hard to envision why a head of state would want or need his own private tube full of air running underneath the Sahara. The obvious guess is that the duct might be used to create a secure communications system, independent of the civilian and military systems (the Egyptian military will own one of the six ducts, and ARENTO will own three). This, in and of itself, says something about the relationship between the military and the government in Egypt. It is hardly surprising when you consider that Mubarak’s predecessor was murdered by the military during a parade.

  Inside the city, where ten rather than six ducts are being prepared, they must occasionally sprout up out of the ground and run along the undersides of bridges and flyovers. In these sections it is easy to identify FLAG’s duct because, unlike the others, it is galvanized steel instead of PVC. FLAG undoubtedly specified steel for its far greater protective value, but in so doing posed a challenge for Engineer Musalam, who knew that thieves would attack the system wherever they could reach it — not to take the cable but to get their hands on that tempting steel pipe. So, wherever the undersides of these bridges and flyovers are within 2 or 3 meters of ground level, Engineer Musalam has built in special measures to make it virtually impossible for thieves to get their hands on FLAG’s pipe.

  For the most part, the duct installation is a simple cut-and-cover operation, right down the median strip. But the median is crossed frequently by nicely paved, heavily trafficked U-turn routes. To cut or block one of these would be unthinkable, since no journey in Egypt is complete without numerous U-turns. It is therefore necessary to bore a horizontal tunnel under each one, run a 600-mm steel pipe down the tunnel, and finally thread the ducts through it. The tunnels are bored by laborers operating big manually powered augers. Under a sign reading Civil Works: Fiberoptic Link around the Globe, the men had left their street clothes carefully wrapped up in plastic bags, on the shoulder of the road. They had kicked off their shoes and changed into the traditional, loose, ankle-length garment. One by one, they disappeared into a tunnel barely big enough to lie down in, carrying empty baskets, then returned a few minutes later with baskets full of dirt, looking like extras in some new Hollywood costume drama: The Ten Commandments Meets the Great Escape.

  We blundered across Engineer Musalam’s path one afternoon. This was sheer luck, but also kind of inevitable: other than ditch diggers, the only people in the median strip of this highway are hacker tourists and ARENTO engineers. He was here because one of the crews working on FLAG had, while enlarging a manhole excavation, plunged the blade of their backhoe right through the main communications cable connecting Egypt to Libya — a 960-circuit coaxial line buried, sans conduit, in the same median. Libya had dropped off the net for a while until Mu’ammar Gadhafi’s eastbound traffic could be shunted to a microwave relay chain and an ARENTO repair crew had been mobilized. The quality of such an operation is not measured by how frequently cables get broken (usually they are broken by other people) but by how quickly they get fixed afterward, and by this standard Engineer Musalam runs a tight ship. The mishap occurred on a Friday afternoon — the Muslim sabbath — the first day of a three-day weekend and a national holiday to boot — 40 years to the day after the Suez Canal was handed over to Egypt. Nevertheless, the entire hierarchy was gathered around the manhole excavation, from ditch diggers hastily imported from another nearby site all the way up to Engineer Musalam.

  The ditch diggers made the hole even larger, whittling out a place for one of the splicing technicians to sit. The technicians stood on the brink of the pit offering directions, and eventually they jumped into it and grabbed shovels; their toolboxes were lowered in after them on ropes, and their black dress trousers and crisp white shirts rapidly converged on the same color as the dust covered them. In the lee of an unburied concrete manhole nearby, a couple of men established a little refreshment center: one hubbly-bubbly and one portable stove, shooting flames like a miniature oil well fire, where they cranked out glass after glass of heavily sweetened tea. This struck me as more efficient than the American technique of sending a gofer down to the 7-Eleven for a brace of Super Big Gulps. Traffic swirled around the adjacent U-turn; motorists rolled their windows down and asked for directions, which were cheerfully given. Egyptian males are not afraid to hold hands with each other or to ask for directions, which does not mean that they should be confused with sensitive New Age males.

  The mangled ends of the cable were cleanly hacksawed and stripped, and a 2-meter-long segment of the same type of cable was wrestled out of a car and brought into the pit. Two lengths of lead pipe were threaded onto it, later to serve as protective bandages for the splices, and then the splicing began, one conductor at a time. Engineer Musalam watched attentively while I badgered him with nerdy questions. He brought me up to speed on the latest submarine cable gossip. During the previous month, in mid-June, SEA-ME-WE 2 had been cut twice between Djibouti and India. Two cable ships, Restorer and Enterprise, had been sent to fix the breaks. But fire had broken out in the engine room of the Enterprise (maybe a problem with the dilithium crystals), putting it into repairs for four weeks. So Restorer had to fix both breaks. But because of bad weather, only one of the faults had been repaired as of July 26. In the meantime, all of SEA-ME-WE 2’s traffic had been shunted to a satellite link reserved as a backup.

  Satellite links have enough bandwidth to fill in for a second-generation optical cable like SEA-ME-WE 2 but not enough to replace a third-generation one like FLAG or SEA-ME-WE 3. The cable industry is therefore venturing into new and somewhat unexplored territory with the current generation of cables. It is out of the question to run such a system without having elaborate backup plans, and if satellites can’t hack it anymore, the only possible backup is on another cable — almost by definition, a competing cable. So as intensely as rival companies may compete with each other for customers, they are probably cooperating at the same time by reserving capacity on each other’s systems. This presumably accounts for the fact that they are eager to spread nasty information about each other but will never do so on the record.

  I didn’t know the exact route of SEA-ME-WE 3 and was intrigued to learn that it will be passing through the same building in Alexandria as SEA-ME-WE 1 and 2, which is also the same building that will be used by FLAG. In addition, there is a new submarine cable called Africa 1 that is going to completely encircle that continent, it being much easier to circumnavigate Africa with a cable-laying ship than to run ducts and cables across it (though I would like to see Alan Wall have a go at it). Africa 1 will also pass through Engineer Musalam’s building in Alexandria, which will therefore serve as the cross-connect among essentially all the traffic of Africa, Europe, and Asia.

  Though Engineer Musalam is not the type who would come out and say it, the fact is that in a couple of years he’s going to be running what is arguably the most important information nexus on the planet.

  As the sun dropped behind the western Sahara (I imagined Mu’ammar Gadhafi out there somewhere, picking up his telephone to hear a fast busy signal), Engineer Musalam drove me into Alexandria in his humble subcompact to see this planetary nexus.

  It is an immense neoclassical pile constructed in 1933 by the British to house their PTT operations. Since then, it has changed very little except for the addition of a window air conditioner in Engineer Musalam’s office. The building faces Alexandria’s railway station across an asphalt square crowded with cars, trucks, donkey carts, and pedestrians.

  I do not think any other hacker tourist will ever make it inside this building. If you do so much as raise a camera to your face in its vicinity, an angry man in a uniform will charge up to you and let you get a very good look at the bayonet fixed to the end of his automatic weapon. So let me try to convey what it is like:

  The adjective Blade-Runneresq
ue means much to those who have seen the movie. (For those who haven’t, just keep reading.) I will, however, never again be able to watch Blade Runner, because all of the buildings that looked so cool, so exquisitely art-directed in the movie, will now, to me, look like feeble efforts to capture a few traces of ARENTO’s Alexandria station at night.

  The building is a titanic structure that goes completely dark at night and becomes a maze of black corridors that appear to stretch on into infinity. Some illumination, and a great deal of generalized din, sifts in from the nearby square through broken windows. It has received very limited maintenance in the last half-century but will probably stand as long as the Pyramids. The urinals alone look like something out of Luxor. The building’s cavernous stairwells consist of profoundly worn white marble steps winding around a central shaft that is occupied by an old-fashioned wrought-iron elevator with all of the guts exposed: rails, cables, counterweights, and so on. Litter and debris have accumulated at the bottom of these pits. At the top, nocturnal birds have found their way in through open or broken windows and now tear around in the blackness like Stealth fighters, hunting for insects and making eerie keening noises — not the twitter of songbirds but the alien screech of movie pterodactyls. Gaunt cats prowl soundlessly up and down the stairs. A big microwave relay tower has been planted on the roof, and the red aircraft warning lights hang in the sky like fat planets. They shed a vague illumination back into the building, casting faint cyan shadows. Looking into the building’s courtyards you may see, for a moment, a human figure silhouetted in a doorway by blue fluorescent light. A chair sits next to a dust-fogged window that has been cracked open to let in cool night air. Down in the square, people are buying and selling, young men strolling hand in hand through a shambolic market scene. In the windows of apartment buildings across the street, women sit in their colorful but demure garments holding tumblers of sweet tea.

  In the midst of all this, then, you walk through a door into a vast room, and there it is: the cable station, rack after rack after rack of gleaming Alcatel and Siemens equipment, black phone handsets for the order wires, labeled Palermo and Tripoli and Cairo. Taped to a pillar is an Arabic prayer and faded photograph of the faithful circling the Ka’aba. The equipment here is of a slightly older vintage than what we saw in Japan, but only because the cables are older; when FLAG and SEA-ME-WE 3 and Africa 1 come through, Engineer Musalam will have one of the building’s numerous unused rooms scrubbed out and filled with state-of-the-art gear.

  A few engineers pad through the place. The setup is instantly recognizable; you can see the same thing anywhere nerds are performing the kinds of technical hacks that keep modern governments alive. The Manhattan Project, Bletchley Park, the National Security Agency, and, I would guess, Saddam Hussein’s weapons labs are all built on the same plan: a big space ringed by anxious, ignorant, heavily armed men, looking outward. Inside that perimeter, a surprisingly small number of hackers wander around through untidy offices making the world run.

  If you turn your back on the equipment through which the world’s bits are swirling, open one of the windows, wind up, and throw a stone pretty hard, you can just about bonk that used book peddler on the head. Because this place, soon to be the most important data nexus on the planet, happens to be constructed virtually on top of the ruins of the Great Library of Alexandria.

  The Lalla Rookh

  When William Thomson became Lord Kelvin and entered the second phase of his life — tooling around on his yacht, the Lalla Rookh — he appeared to lose interest in telegraphy and got sidetracked into topics that, on first reading, seem unrelated to his earlier interests — disappointingly mundane. One of these was depth sounding, and the other was the nautical compass.

  At the time, depths were sounded by heaving a lead-weighted rope over the side of the ship and letting it pay out until it hit bottom. So far, so easy, but hauling thousands of meters of soggy rope, plus a lead weight, back onto the ship required the efforts of several sailors and took a long time. The US Navy ameliorated the problem by rigging it so that the weight could be detached and simply discarded on the bottom, but this only replaced one problem with another one in that a separate weight had to be carried for each sounding. Either way, the job was a mess and could be done only rarely. This probably explains why ships were constantly running aground in those days, leading to a relentless, ongoing massacre of crew and passengers compared to which today’s problem of bombs and airliners is like a Sunday stroll through Disney World.

  In keeping with his general practice of using subtlety where moronic brute force had failed, Kelvin replaced the soggy rope with a piano wire, which in turn enabled him to replace the heavy weight with a much smaller one. This idea might seem obvious to us now, but it was apparently quite the brainstorm. The tension in the wire was so light that a single sailor could reel it in by turning a spoked wooden wheel.

  The first time Kelvin tried this, the wheel began to groan after a while and finally imploded. Dental hygienists, or people who floss the way they do (using extravagantly long pieces of floss and wrapping the used part around a fingertip) will already know why. The first turn of floss exerts only light pressure on the finger, but the second turn doubles it, and so on, until, as you are coming to the end of the process, your fingertip has turned a gangrenous purple. In the same way, the tension on Kelvin’s piano wire, though small enough to be managed by one man, became enormous after a few hundred turns. No reasonable wheel could endure such stress.

  Chagrined and embarrassed, Kelvin invented a stress-relief mechanism. On one side of it the wire was tight, on the other side it was slack and could be taken up by the wheel without compressing the hub. Once this was out of the way, the challenge became how to translate the length of piano wire that had been paid out into an accurate depth reading. One could never assume that the wire ran straight down to the bottom. Usually the vessel was moving, so the lead weight would trail behind it. Furthermore, a line stretched between two points in this way forms a curve known to mathematicians as a catenary, and of course the curve is longer than a straight line between the same two points. Kelvin had to figure out what sorts of catenary curves his piano wire would assume under various conditions of vessel speed and ocean depth — an essentially tedious problem that seems well beneath the abilities of the father of thermodynamics.

  In any case, he figured it out and patented everything. Once again he made a ton of money. At the same time, he revolutionized the field of bathymetry and probably saved a large number of lives by making it easier for mariners to take frequent depth soundings. At the same time, he invented a vastly improved form of ship’s compass which was as big an improvement over the older models as his depth-sounding equipment was over the soggy rope. Attentive readers will not be surprised to learn that he patented this device and made a ton of money from it.

  Kelvin had revolutionized the art of finding one’s way on the ocean, both in the vertical (depth) dimension and in the horizontal (compass) dimensions. He had made several fortunes in the process and spent a great deal of his intellectual gifts on pursuits that, I thought at first, could hardly have been less relevant to his earlier work on undersea cables. But that was my problem, not his. I didn’t figure out what he was up to until very close to the ragged end of my hacker tourism binge.

  Slack

  The first time a cable-savvy person uses the word slack in your presence, you’ll be tempted to assume he is using it in the loose, figurative way — as a layperson uses it. After the eightieth or ninetieth time, and after the cable guy has spent a while talking about the seemingly paradoxical notion of slack control and extolling the sophistication of his ship’s slack control systems and his computer’s slack numerical-simulation software, you begin to understand that slack plays as pivotal a role in a cable lay as, say, thrust does in a moon mission.

  He who masters slack in all of its fiendish complexity stands astride the cable world like a colossus; he who is clueless about slack either
snaps his cable in the middle of the ocean or piles it in a snarl on the ocean floor — which is precisely what early 19th-century cable layers spent most of their time doing.

  The basic problem of slack is akin to a famous question underlying the mathematical field of fractals: How long is the coastline of Great Britain? If I take a wall map of the isle and measure it with a ruler and multiply by the map’s scale, I’ll get one figure. If I do the same thing using a set of large-scale ordnance survey maps, I’ll get a much higher figure because those maps will show zigs and zags in the coastline that are polished to straight lines on the wall map. But if I went all the way around the coast with a tape measure, I’d pick up even smaller variations and get an even larger number. If I did it with calipers, the number would be larger still. This process can be repeated more or less indefinitely, and so it is impossible to answer the original question straightforwardly. The length of the coastline of Great Britain must be defined in terms of fractal geometry.

  A cross-section of the seafloor has the same property. The route between the landing station at Songkhla, Thailand, and the one at Lan Tao Island, Hong Kong, might have a certain length when measured on a map, say 2,500 kilometers. But if you attach a 2,500-kilometer cable to Songkhla and, wearing a diving suit, begin manually unrolling it across the seafloor, you will run out of cable before you reach the public beach at Tong Fuk. The reason is that the cable follows the bumpy topography of the seafloor, which ends up being a longer distance than it would be if the seafloor were mirror-flat.

  Over long (intercontinental) distances, the difference averages out to about 1 percent, so you might need a 2,525-kilometer cable to go from Songkhla to Lan Tao. The extra 1 percent is slack, in the sense that if you grabbed the ends and pulled the cable infinitely tight (bar tight, as they say in the business), it would theoretically straighten out and you would have an extra 25 kilometers. This slack is ideally molded into the contour of the seafloor as tightly as a shadow, running straight and true along the surveyed course. As little slack as possible is employed, partly because cable costs a lot of money (for the FLAG cable, $16,000 to $28,000 per kilometer, depending on the amount of armoring) and partly because loose coils are just asking for trouble from trawlers and other hazards. In fact, there is so little slack (in the layperson’s sense of the word) in a well-laid cable that it cannot be grappled and hauled to the surface without snapping it.