WATD

Seamless Wireless Roaming

Background

In early July on the way back from DEFCON 9, I was considering Peter Shipley's (http://www.dis.org/shipley) talk on wardriving (http://www.dis.org/wl), as well as the talks on open access wireless networks, like Personal telco and NYC wireless.

Wouldn't it be a cool idea to have a continuous network experience, such as a web-surfing session, while riding a bus through a series of autonomous wireless networks? For example, the Bay Area Wireless Users Group (BAWUG) has a large list of open-access wireless APs. However, most (if not all) these APs are standalone NAPS, not associated into an ESS. So if we try to move from one to another while in the middle of, say, a TCP connection, that connection would die because one endpoint would no longer be valid.

To create a continuous experience, then, we have to tunnel all of our traffic through a computer running NAT, which has a static IP address. Each user has a client (which is currently for FreeBSD) which tunnels traffic to the server, which performs NAT on the traffic and re-tunnels returning traffic back to the client. The client uses whatever APs are available, and can move between autonomous systems without losing *too* much traffic due to the switching. (That said, the planned tunnelling mechanism doesn't guarantee delivery of all datagrams, since it operates at the network and link layers. C'est la vie, oui?)

All input is welcome. You can contact me at the anti-spam address cerastes.crunchy.peanut.butter@cerastes.org (remove the obvious parts) with ideas. Don't worry, i'll give credit to whoever gives me good ideas. :)

A cursory plot of the various functions and operations that the client will perform is available here. Also, I have put a preliminary description of the protocol structure at the given link. As always, comments are appreciated.

Status

As it turns out, someone else has already started a project for Linux to work on something called Mobile IP. They beat me to it. In any case, I may see if there's something for me to contribute. In the meantime, I'll have to just not do this, and instead find another project.

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