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Massive Fiber Cut Slows Net
netpuppy writes "East coast to west coast connectivity (or the other way around) feeling slow today? Here's why. It appears that the attack of the raging backhoes has hit Ohio today, where an unnamed public utility managed to cut through 4 OC-192 circuits while working on gas lines. 4 OC-192s are roughly equivalent to 40 Gbps traffic, and trunks this size usually carry both voice and data on them. AboveNet, GTE, and Metro Fiber (now part of Worldcom) seem to be the worst hit, according to this Inter@ctive Week article. " OK, I'm not just crazy. It has been slower then molasses today.
Good thing there wasn't anyone around there smoking a cigarette. What with all those loose bits sloshing around, the slightest spark could have set off that 'internet explosion' people keep telling me about.
Trees can't go dancing
So do them a big favor
Pretend dancing stinks!
Well, the powering issue being talked about isn't exactly what would be called "common". Most fiber in the ground today has no current-carrying conductors. True, it has a metallic conductor or two in it, and in some cases, a metallic sheath or armour, but carries no exectricity. The metal conductor is used exclusively to locate the cable with inductive/RF location gear. When it comes to re-generation of fiber "signals", byt simple amplification, or a full teardown of the bitstream with drop/add functionality, it's usually done at a special location (in-ground vault, above ground fiber hut, whatever) with external power. That's power supplied by a power company, with backup power. Since fiber traffic routinely travels 50+km without intervention at all, it's a total waste of resources and cable to lay a power cable for equipment. Now, all said, there are exceptions where there is no power readily available, like deep-sea cables, deserts, and such where there may be a power cable present in places. But in general, not present. Now, back to a little more on topic :) As for location, depending on the area, this can be tricky business, big time. In dense metropolitan areas, there can quite literally be cables a foot or less apart "horizontally" as well as several layers deep "vertically". Location of cables isn't always as precise as it ought to be, especially when the phone companies records don't reflect actual construction oddities, like perhaps a four foot fiber "loop" at the base of a pedestal. Well, when the person locating cable gets within a couple feet of a pedestal, you'd just assume it goes right in, right? Wrong :) And another company plans to put a pedestal right next to the existing one, and, well, it's time to break out the Scotch-Lok or quick-fix fiber kit :) Granted, most cable and fiber cuts happen out of pure ignorance or stupidity. Farmer Joe is out in the field fixing a drainage tile with his tractor and doesn't give a single thought to what else may be in the ditch with his tile. Where did those kits go again? :) And as a final note on the buried cable thing, nowadays, it's becoming common, almost required, practice to bury a brightly colored plastic ribbon above the cable being installed. Usually yellow or orange, it's really easy to see against black dirt, and would hopefully be seen before the contractor hits the cable itself. Doesn't do much good in the case of boring or knifing cable in though. All of this is just general information. The cut out east could have been done in one of a dozen or more other common contractor cable goofs that I won't even try to speculate on. Either way, it boils down to this - contractor started digging without requesting a locate, or if the cable was properly located, and the contractor either mis-read the location markings, or ignored them, that contractor had better hope he has a good insurance company. If the cable was not located at all, and a locate request was made and recorded in a timely manner, usually 24 to 48 hours before digging, well it's the telco's tough luck. You know, it's a small wonder that things work as well as they do considering the unimaginable number of perils out there, backhoe's included :) Sorry this is so long! FBG the AC
From Wired 4.12 ... article called Mother Earth Mother Board ... url at http://www.wired.com/wired/archive/4.12/ffglass.ht ml
The signal coming down the FLAG cable passes through the doped fiber and causes it to lase, i.e., the excited electrons drop back down to a lower energy level, emitting light that is coherent with the incoming signal - which is to say that it is an exact copy of the incoming signal, except more powerful.
The amplifiers need power - up to 10,000 volts DC, at 0.9 amperes. Since public 10,000-volt outlets are few and far between on the bottom of the ocean, this power must be delivered down the same cable that carries the fibers. The cable, therefore, consists of an inner core of four optical fibers, coated with plastic jackets of different colors so that the people at opposite ends can tell which is which, plus a thin copper wire that is used for test purposes. The total thickness of these elements taken together is comparable to a pencil lead; they are contained within a transparent plastic tube. Surrounding this tube is a sheath consisting of three steel segments designed so that they interlock and form a circular jacket. Around that is a layer of about 20 steel "strength wires" - each perhaps 2 mm in diameter - that wrap around the core in a steep helix. Around the strength wires goes a copper tube that serves as the conductor for the 10,000-volt power feed. Only one conductor is needed because the ocean serves as the ground wire. This tube also is watertight and so performs the additional function of protecting the cable's innards. It then is surrounded by polyethylene insulation to a total thickness of about an inch. To protect it from the rigors of shipment and laying, the entire cable is clothed in good old-fashioned tarred jute, although jute nowadays is made from plastic, not hemp.
good. fast. cheap. (pick any two, you can't have all three)
I checked out the Internet traffic report to see what kind of effect this harmless mistake had. North American traffic statistics
Keen! Can you spot the time the big bad backhoe operator cut the cord?