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Re: [RRG] Geographic aggregation-based routing is at odds with reality
On 18 jul 2008, at 9:47, Tony Li wrote:
The issue with this approach is again one of cooperation: those folks
performing the maintenance of the aggregation are NOT those that
benefit
from it. The up side is that if everyone were cooperative (you
scratch my
back, I'll scratch yours), then mutual aggregation would distribute
both the
costs AND the benefits. If providers could be enticed to enter into
such a
multilateral (and informal!) agreement, we could make significant
progress.
I don't see that.
If I want to shrink my routing tables I can filter out any Canadian
more specifics all over the world except in Canada, and instead put in
an aggregate that covers the address space used in Canada.
(This requires that Canadian address space can be identified through a
small number of prefixes and that I can easily make exceptions for
more specifics to Canadian destinations that I can't reach through
peerig inside Canada, but only elsewhere.)
If you are also a large network with customers in Canada, I don't care
whether you also implement this aggregation or not. I can either do
hot potato and give you the Canadian traffic close to the source and
thus optimize for traffic flow, or filter those more specific,
transport the traffic to Canada and then give it to you, optimizing
for routing table size.
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