Sunday, May 9, 2010

Internet Data Routes: "It's ugly when you look under the cover"

Link to May 9 San Jose Mercury News article, "How an unfixed Internet glitch could strand you offline".

Excerpt: The crux of the problem is that each carrier along the way figures out how to route the data based only on what the surrounding carriers in the chain say, rather than by looking at the whole path. It's as if a driver had to get from Philadelphia to Pittsburgh without a map, navigating solely by traffic signs he encountered along the way — but the signs weren't put up by a central authority. If a sign pointed in the wrong direction, that driver would get lost.

That's essentially what happens when an Internet route gets hijacked. Because carriers pass information between themselves about where data should go — and this system has no secure, automatic means of verifying that the routing information is correct — data can be routed to some carrier that isn't expecting the information. The carrier doesn't know what to do with it, and usually just drops it. It falls into a "black hole."

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