Hi Dmitri,

Might I suggest that a discussion of transit policies might also be in order?

Thanks,
Tony


On Sep 13, 2010, at 3:08 PM, Dmitri Krioukov wrote:

> thanks much for you comments! indeed, topology dynamics is
> concern #1 in geometric routing. that's why we considered both
> short- and long-term dynamics, all in the paper. we emulate the
> former (by killing a percentage of links and nodes) and
> replayed the latter using the measurable history of internet
> evolution over the past few years with ASs and AS connections
> appearing, disappearing, etc., and the results are still very
> good, pretty much the same as for the static case. amazing,
> isn't it? i know it's hard to believe, and even we can't stop being
> surprised how well it works. we have another paper in submission,
> where we take space to explain why it works so well, and where
> we discuss some aspects of what it would take to implement
> and use this stuff in practice.
> -- 
> dima.
> http://www.caida.org/~dima/
> 
> On Friday, September 10, 2010 4:29 PM, Sampo Syreeni wrote:
> 
>> 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 - [email protected], http://decoy.iki.fi/front
>> +358-50-5756111, 025E D175 ABE5 027C 9494 EEB0 E090 8BA9 0509 85C2
> 
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