Internet users in China found themselves unable to access any foreign websites for about an hour Thursday morning (local time), prompting speculation that China's extensive censorship system was being tested or tightened.
China's "great firewall" regularly blocks many sites hosted in other countries, but web users in many areas reported they were unable to reach any foreign sites at all - even "approved" websites. At about the same time, there were reports from Hong Kong (which lies outside the "great firewall") and elsewhere that web users were unable to access any websites hosted on the Chinese mainland.
While there was no immediate official recognition or explanation offered for the service interruption, one high official at a major Chinese internet portal suggested it was a result of a technical failure in the backbone network. Others suggested it might have been a result of a software upgrade in backbone operations, or even an adjustment to the list of blocked foreign sites that got out of control. Speculation that the disruption was intentional and related to official censorship efforts was fueled by a recent crackdown on "internet rumors" that had resulted in the removal of more than 200,000 online posts and the closure of more than 40 websites in the last month.
China's connection to the outside Internet is funneled through three channels, making it easier to monitor and block international data flows. Relying on only a few interconnections, however, also makes the system more vulnerable to a technical problem or failure at those key points. Given their history, while Chinese authorities will eventually release an official explanation, speculation about the real cause will continue for a while.
Source - China's internet users temporarily blocked from foreign websites, The Guardian (UK)
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