Useless TriviaΒΆ

This section written by the original author, Avery Pennarun <>.

Back in 1998, I released the first version of Tunnel Vision, a semi-intelligent VPN client for Linux. Unfortunately, I made two big mistakes: I implemented the key exchange myself (oops), and I ended up doing TCP-over-TCP (double oops). The resulting program worked okay - and people used it for years - but the performance was always a bit funny. And nobody ever found any security flaws in my key exchange, either, but that doesn’t mean anything. :)

The same year, dcoombs and I also released Fast Forward, a proxy server supporting transparent proxying. Among other things, we used it for automatically splitting traffic across more than one Internet connection (a tool we called “Double Vision”).

I was still in university at the time. A couple years after that, one of my professors was working with some graduate students on the technology that would eventually become Slipstream Internet Acceleration. He asked me to do a contract for him to build an initial prototype of a transparent proxy server for mobile networks. The idea was similar to sshuttle: if you reassemble and then disassemble the TCP packets, you can reduce latency and improve performance vs. just forwarding the packets over a plain VPN or mobile network. (It’s unlikely that any of my code has persisted in the Slipstream product today, but the concept is still pretty cool. I’m still horrified that people use plain TCP on complex mobile networks with crazily variable latency, for which it was never really intended.)

That project I did for Slipstream was what first gave me the idea to merge the concepts of Fast Forward, Double Vision, and Tunnel Vision into a single program that was the best of all worlds. And here we are, at last. You’re welcome.