In a physical attack, disabling communications in the U.S. would be a frightfully simple task because both voice and data traffic move through as few as four buildings in some cities, and many are far less secure than they probably should be.
Take out the main central office, cable headend, telecom hotel and carrier-neutral peering point in a particular city, and all but the simplest Internet-based communications would be seriously disrupted.
There would be no cable television. Businesses would not have working telephones or high-speed Internet connections. Most would not be able to facilitate any paperless transactions because all data lines, from frame relay to Gigabit Ethernet, would go dark. Wireless calls would fail to be completed. Many Web sites would go dark. The Internet would slow to a crawl, rendering such things as instant messaging unusable. ISPs would have no dial tone. Cable and DSL modems would fail.
The new networking message is clear: In the wake of the latest terrorist attacks, modern information-based companies can no longer afford to rely on infrastructure with single points of failure. The best insurance, networking experts say, is in geographic diversity.
While most Internet traffic is exchanged at five high-profile locations - Metropolitan Area Exchange East and MAE West, and NAPs owned by Ameritech, Pacific Bell and Sprint - a lot of the traffic is exchanged privately between major carriers.
An attack on major backbones owned by Cable & Wireless, Genuity, Sprint or WorldCom could be devastating, but built-in rerouting redundancies make the Internet truly hard to kill. Data traffic on major backbones is handed off at 50 or so locations, and could be rerouted through a large number of "ghost routes" that even the best-connected networking professionals cant count. Internet networks are often interconnected in unmarked manholes on the street, which adds to the security.
"Unless you are a company insider, you cant tell the difference between a green telephone box which serves Aunt Minnie, and a green telephone box which serves the First National Bank by looking at it," one networking engineer said.
But redundancies grow slim as customers start using facilities such as telecom hotels, carrier exchanges and telephone companies central offices.
"Should companies, banks, stock houses and other financial institutions be in facilities like telecom hotels? No. They should get out of there," Pacific Bells Clairmont said.
These buildings are connectivity hubs for telephones; DSL, dial-up and cable modems; T1 (1.5-megabit-per-second) leased lines; and high-speed fiber connections. Needless to say, their loss would be devastating.