Updated: Syria is cut off from the Internet, according to The Renesys blog and other media sites citing Syrian rebels, bringing about an isolation that many feared was coming to the country. The country is engaged in a citizen-led insurgency against the existing government, which was sparked after Syrian President Bashar Assad brutally cracked down on protesters.
The Renesys blog entry is short, and promises updates. From the Renesys blog:
Starting at 10:26 UTC (12:26pm in Damascus), Syria’s international Internet connectivity shut down. In the global routing table, all 84 of Syria’s IP address blocks have become unreachable, effectively removing the country from the Internet.
Cutting off entire countries form the global Internet has become a strategy employed by some governments in times of civil unrest — and underscores many of the weak points of the Internet itself. Both Libya, Iran and Egypt pulled much of their connections to the web world offline in the last two years. We explained how Egypt took the country offline in this post:
The OpenNet Initiative has outlined two methods by which most nations could enact such shutdowns. Essentially, officials can either close down the routers which direct traffic over the border — hermetically sealing the country from outsiders — or go further down the chain and switch off routers at individual ISPs to prevent access for most users inside.
At the time Egypt took the second route to take the country offline, a process made easier by the fact that their were few ISPs to contact. It’s unclear how Syria disconnected its citizens. Some news reports say insurgents are communicating still via satellite phones, but the lost of IP addresses means no IP services can find their way to end users within the country. When a packet destined for a Syrian IP address is sent, it simply can’t find out where it’s supposed to go.
Update: Here’s what that drop off in traffic looks like, courtesy of Akamai (s akam).
This is one reason that technologies such as OpenBTS, Commotion, the Serval Project and other technologies to build out open source communications networks are important. While those may not ensure that people in Syria can talk to the outside world unless they have a satellite backhaul, they could still communicate with one another independently of the local ISPs.