BGP (in)security makes the AP wire
Neil Harris
neil at tonal.clara.co.uk
Fri Feb 18 13:42:14 UTC 2011
On 18/02/11 12:26, Eugen Leitl wrote:
> On Sun, May 09, 2010 at 09:38:18AM -0700, Joel Jaeggli wrote:
>
>> geographic location doesn't map to topology
> In LEO satellite constellations and mesh wireless it typically does.
> When bootstrapping a global mesh, one could use VPN tunnels over
> Internet to emulate long-distance links initially.
>
> Eben Moglen recently proposed a FreedomBox intitiative, using ARM
> wall warts to build an open source cloud with an anonymizing layer.
> Many of these come with 802.11x radio built-in. If this project
> ever happens, it could become a basis for end-user owned
> infrastructure. Long-range WiFi can compete with LR fiber
> in principle, though at a tiny fraction of throughput.
>
"Tiny fraction" is putting it mildly. I once considered starting up a
low-infrastructure wireless ISP using mesh radio based on wifi radio
technology adapted to work in licensed bands.
If you work out the numbers, the bandwidth you get in any substantial
deployment is pitiful compared to technologies like DSL and cable
modems, let alone fiber.
New technologies such as distributed space-time multipath coding on the
wireless side, and multipath network coding on the bitstream side, look
like the way forward on this, but these are brand new, and still the
subject of research -- you certainly can't just hot-wire these onto wifi
hardware.
>>> Presumably, one could prototype something simple and cheap at L2 level
>>> with WGS 84->MAC (about ~m^2 resolution), custom switch firmware and GBIC
>>> for longish (1-70 km) distances, but without a mesh it won't work.
> The local 64 bit part of IPv6 has enough space for global ~2 m resolution,
> including altitide (24, 24, 16 bit). With DAD and fuzzing lowest
> significant bits address collisions could be prevented reliably.
>
> Central authority and decentralism can co-exist.
Indeed.
The fact that the usable bandwidth resulting from ad-hoc mesh wiki would
be tiny compared to broadband connections doesn't mean this sort of
thing isn't worth trying: a few tens of kilobits a second is plenty for
speech, and even a few hundred bits per second useful for basic text
messaging.
Given that the cost of doing this is almost zero, since only software is
required to implement it on any modern wifi/GPS equipped mobile
hardware, this seems like a great thing to have in the general portfolio
of networking technologies: having something like this available could
be invaluable in disaster/crisis situations.
-- Neil
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