Check Up on Your ISP with Switzerland

The FCC voted this morning to tell Comcast that they'd been bad boys for blocking some traffic on their network. Unfortunately, as our parent blog GigaOM covered, they chose not to make any sweeping rules about the matter. So how do you know if your ISP is playing fast and loose with your packets? That's where Switzerland, a new tool from the EFF, comes in.

The idea of Switzerland (released in alpha under GPL 3.0) is simple. You install the client on two computers, and set up a Switzerland server on a third. The EFF is providing a public Switzerland server to get people started. Then you send traffic back and forth between the two client machines. Each of them sends a hashed summary of the traffic it sees to the server. If the server notices a difference, that's pretty good evidence that someone between point A and point B is tampering with the traffic.

Of course, you need to have some reasonable Internet chops to know where to pin the blame. Though Switzerland knows about and allows for NAT, it's entirely possible for your router to make other arbitrary changes to the packets that it sees in the name of efficiency. For a good test, you really need to be using two clients plugged directly into the Net.

The other problem is finding someone to swap traffic with. The EFF has set up a wiki page to collect information on public Switzerland clients that can be used for testing, but right now it's pretty bare. If you're looking for an offbeat way to contribute to open source without writing code, running a Switzerland public client could be the answer.

Switzerland is designed to run on all sorts of machines - Linux, OS X, Windows. It requires reasonably recent Python and libpcap to do its job.