The network monitoring group Renesys reported on Thursday that 77 networks — 92% of the country’s total — began experiencing outages at 10:26 Greenwich Mean Time.

But Syria’s apparently systematic disconnection from the internet actually began at least a week earlier, according to research by the SecDev Group internet analytics firm. Around the middle of the month, Syria’s ordinary handful of daily requests to withdraw from Syria’s BGP [Border Gateway Protocol] routes started to grow to a few hundred per. These connections are what enables one national network to interface with the broader internet. On November 22, the withdrawals suddenly jumped to more than 2000. An even greater spike occurred on November 29.

“When a country withdraws itself from the internet using BGP such as Syria has, it means that on a technical level no one knows how to get there anymore, because there are no longer any paths, effectively shutting off the internet in the region,” SecDev explains in a draft report.

“On some networks there are still some paths in place,” Ginley adds. “But this could be to maintain some limited communication or perhaps it’s just an error on their side.”

The communications blackout — which, according to some local reports, also briefly included cell and landline phone service – is hugely important to the war effort in Syria. The rebels don’t just use these networks to share information with one another. They train their forces and document regime atrocities with YouTube clips. The government has been known to shut down internet service in a particular city in advance of a major attack.

“But this is the first time are seeing it centralized (from what I can tell),” emails SecDev CEO Rafal Rohozinski, who has been working with Syrian opposition groups. “We are trying to ascertain whether this is a deliberate pulling of the plug, a technical error, or something else.”

Damascus International Airport has also reportedly disappeared from some flight radars.

[link to www.wired.com]