China's tens of millions of Internet users are suffering sharp slowdowns in access, which industry experts blame in part on heightened efforts by the communist government to police online content.
Some say problems have worsened this week, suggesting Beijing is tightening surveillance during the annual meeting of China's parliament.
The slowdown highlights the clash between China's efforts to reap the Internet's benefits and communist zeal to control what its people read and hear. Authorities have invested both in spreading Web access nationwide and installing technology to scan Web sites and e-mail for content deemed subversive or obscene.
Problems emerged in October after "packet-sniffer" software was installed that briefly holds each chunk of data to be screened. Beijing has built an online barrier around China, requiring traffic in and out to pass through just eight gateways -- a step that heightens official control.
Banned topics include human rights and the outlawed Falun Gong spiritual group.
Each item emerging from China bears the same Internet return address, showing that all are held up at the same location rather than coming directly from their senders, said Michael Iannini, general manager of Nicholas International Consulting Services Inc in Beijing.
Iannini compares it to all of China's Web surfers -- a population that the government says hit 59 million in January -- breathing through the same tiny air hole.
"Through this hole the government has set up many filters," he said.
The snarl is worsened by the breakup of China's former monopoly phone company amid double-digit growth in its online population, which already is the world's second-biggest.
China Telecom was split into two smaller carriers in a move meant to spur competition and lead to better, cheaper service. But in the short run, it has left China's north in the hands of a spinoff company with sharply lower Internet capacity.
Ordinary users say they have their biggest problems in reaching foreign Web sites and on weekdays, when people go to work and log on at the same time. They say access sometimes is so slow that they can't reach Google, Hotmail and other popular foreign sites -- many based in the US.
"At home sometimes it's too slow to use, and at work, it's even slower," said Sara Li, a former magazine editor in Beijing. Access is even slower, she said, during "special time periods" -- a reference to such politically sensitive events as the National People's Congress under way in Beijing.
Help could come from the spread of faster "broadband" access, which has reached some 4 million users, said Todd Bryan of MFC Insight, a Beijing consulting firm. But he said the lack of a standard national network means many aren't getting the best service.