Re: [rrg] Fwd: Sustaining the Internet with hyperbolic mapping

[Sampo Syreeni <[e-mail]>]

On 2010-09-09, Dmitri Krioukov wrote:

> marshall, thanks for posting it here. i also thinks it's relevant :)

Thanks from me too, and it's certainly relevant. Still, it might not be 
as good an idea as it sells itself as.

Geometric routing ideas have been around for quite a while now. They 
certainly do this sort of thing within manets right now, because of the 
spatial nature of a cloud of terminals/sensors. So in certain ways the 
idea works well indeed.

I'd be the first to say that geometric routing is a swell and elegant 
idea. Yet, it tends to have some inherent problems in the wired setting 
where a) the topology and the geometry of the network isn't as static as 
a cloud of 3D sensors would see, b) where we have to have static contact 
points like DNS fully available at more or less fixed destination 
addresses all of the time, to map from points of interest to 
topological/geometrical addresses/locations, c) any static mapping like 
the one proposed in the paper could *severely* undercut routing 
efficiency as soon as someboby built a new undersea cable, which of 
course severely changes the routing landscape in one fell swoop, and d) 
when we then probably would go with an adaptive routing protocol, there 
is a serious problem with asymmetric paths. That final problem doesn't 
plague just Euclidean distance measures, but all of the metric ones as 
well, including the hyperbolic.

As regards an adaptive geometric routing protocol, IRTF's ALTO group has 
charted this stuff quite extensively already in the context of routing 
within overlay networks. I suggest everybody look into that body if they 
haven't already, if interested in geometric routing.

In my opinion, this particular article is a nice touch onto how best 
parametrize network distance. Based on the article and the references, a 
hyperbolic space might well provide us with a better parametrization of 
distance in a scale-free network within the geometric routing paradigm. 
But it won't solve the more fundamental problems which have stopped us 
from adopting geometric routing in the past.

I'd say this body of work is a building block for further research, more 
than the showstopper it'd like us to see itself as.
-- 
Sampo Syreeni, aka decoy - [e-mail], http://decoy.iki.fi/front
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