The split between these two ways of thinking runs very deep and accounts for much tumult in the telecom world, as will be explained later.) The second generation of optical-fiber cables carries 560 Mbps per fiber pair. FLAG and other third-generation systems will carry 5.3 Gbps per pair. Or, in the system of units typically used by phone company people, they will carry 60,000 circuits on each fiber pair.

If you multiply 60,000 circuits times 64 kbps per circuit, you get a bit rate of only 3.84 Gbps, which leaves 1.46 Gbps unaccounted for. This bandwidth is devoted to various kinds of overhead, such as frame headers and error correction. The FLAG cable contains two sets of fiber pairs, and so its theoretical maximum capacity is 120,000 circuits, or (not counting the overhead) just under 8 Gbps of actual throughput.

These numbers really knock 'em dead in the phone industry. To the hacker tourist, or anyone who spends much time messing around with computer networks, they seem distinctly underwhelming. All this trouble and expense for a measly 8 Gbps? You've got to be kidding! Again, it comes down to a radical difference in perspective between telephony people and internet people.

In defense of telephony people, it must be pointed out that they are the ones who really know the score when it comes to sending bits across oceans. Netheads have heard so much puffery about the robust nature of the Internet and its amazing ability to route around obstacles that they frequently have a grossly inflated conception of how many routes packets can take between continents and how much bandwidth those routes can carry. As of this writing, I have learned that nearly the entire state of Minnesota was recently cut off from the Internet for 13 hours because it had only one primary connection to the global Net, and that link went down. If Minnesota, of all places, is so vulnerable, one can imagine how tenuous many international links must be.



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