James Fallows, national correspondent for The Atlantic Monthly, has experienced "The Great Firewall of China" firsthand, an experience people from around the world will share this summer when the Olympics comes to that country. Based in Beijing, Fallows has researched the underlying technology that the Chinese use for Internet censorship, and he explained it in a recent article titled "The Connection Has Been Reset." We e-mailed Fallows questions about how the Chinese government controls Internet content available to its citizens, and here's what he had to say.

Cisco says it sold China the same mirroring routers that it makes available to any organization that needs to monitor Internet usage by its employees. If that's true, why should Cisco be criticized more than any other network vendor that sells gear to the Chinese? 

This was a minor, passing point in my article, which reflected the fact that I had not done serious independent reporting on the question. What I can do is convey the prevailing view on the question among the Chinese net-cognoscenti. From this perspective, Cisco did a favor to the Chinese government several years ago by selling them the mirroring routers on which the Great Firewall is based, at a time when Chinese authorities could not easily have produced the systems on their own. The likely use of the routers was well understood -- and it should be obvious why selling them to a government which intends to monitor its citizens is different from selling them to some company that wants to monitor its employees. But whatever the merits of the argument back then, the entire question is now moot. The Chinese authorities could buy the necessary routers from a variety of sources -- notably from the homegrown firm Huawei. So, really few people here spend much time worrying about Cisco's role anymore.

You describe four blocking mechanisms that the Chinese government uses to prevent Internet users from viewing content considered harmful. How common is it for Chinese Internet users to experience these sorts of redirections, resets and time-out mechanisms? Can you describe your own Internet surfing experience in China?

If you work from a Chinese Internet cafe -- which is still where the vast majority of Chinese Internet activity happens, since so few people have connected computers in their own homes -- you experience all of these blocking mechanisms as a matter of course. In some places, like schools, the blocking can be much cruder and indiscriminate. For instance, I have been in several public schools where the "connected" Internet computers were prevented from using any search engine whatsoever. It can be surprisingly hard to get around the 'Net if you can't run any searches! In cafes and in most home connections, all the mechanisms I describe would prevail.

In some hotels and other buildings that cater to Western visitors, the controls may be somewhat relaxed. The authorities don't really care that much about what non-Chinese citizens are able to find. But from my apartments in first Shanghai and now Beijing, I was not able to reach a wide variety of sites -- including, often, my own blog at the Atlantic -- unless I connected through a VPN. As a matter of course I fire up my VPN at the start of any online session, not just for security but because otherwise I'll be blocked the first time I try a Wikipedia or Technorati link.

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