Here is a good article on shutdown of net in Egypt.

http://www.nytimes.com/2011/02/16/technology/16internet.html?ref=world

However, I still find it technically confusing. Can the engineers among us again please review for the social scientists what happened here precisely?

Quoting

"One of the government’s strongest levers is Telecom Egypt, a state-owned company that engineers say owns virtually all the country’s fiber-optic cables; other Internet service providers are forced to lease bandwidth on those cables in order to do business.".[ . . . .]

"Yet despite this decentralized design, the reality is that most traffic passes through vast centralized exchanges — potential choke points that allow many nations to monitor, filter or in dire cases completely stop the flow of Internet data." .[ .. . . ]

"There has been intense debate both inside and outside Egypt on whether the cutoff at 26 Ramses Street was accomplished by surgically tampering with the software mechanism that defines how networks at the core of the Internet communicate with one another, or by a blunt approach: simply cutting off the power to the router computers that connect Egypt to the outside world." [ . . . . ]

"Over the next five days, the government furiously went about extinguishing nearly all of the Internet links to the outside world that had survived the first assault, data collected by Western network monitors show. Although a few Egyptians managed to post to Facebook or send sporadic e-mails, the vast majority of the country’s Internet subscribers were cut off." [ . . .. ]

This is a bit clearer

"Individual Internet service providers were also called on the carpet and ordered to shut down, as they are required to do by their licensing agreements if the government so decrees.

According to an Egyptian engineer and an international telecom expert who both spoke on the condition of anonymity, at least one provider, Vodafone, expressed extreme reluctance to shut down but was told that if it did not comply, the government would use its own “off” switch via the Telecom Egypt infrastructure — a method that would be much more time-consuming to reverse. Other exchanges, like an important one in Alexandria, may also have been involved.

Still, even major providers received little notice that the moves were afoot, said an Egyptian with close knowledge of the telecom industry who would speak only anonymously.

“You don’t get a couple of days with something like this,” he said. “It was less than an hour.”" [ . . . .]

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