The model scales well, imho. Regionalize your network into pieces. Apply each of the pieces into 1 or more proximities to a NAP|MAE.
Apply set filter lists onto peering sessions for appropriate peers.
Let me expound.
I run Internet-Net.net. I have a POP in every city w/ over 10,000 people.
I aggregate M number of POPs to N number of Hubs.
(use acronym NXP to mean network exchange point.....)
I am connected to P number of NXPs.
I go through each of my N Hubs, and identify if he is or is not in Pn's region. If he is, I add NXPn's peers to the allow list. If he's not, I don't.
Won't this work? Is it "too confusing"?
Let's say I have 1 HUB in Arizona. I decide that they are in the region of MAE-W, PACBELL, and the NXP in Phoenix. So, I accept routes from everyone at any of those NXPs, and I give my routes for this HUB only, to everyone at the NXP. I don't tell them about my route to customers homed to San Mateo, because I don't want to carry their traffic there, only stuff that's topolgically 'close' to them, as I feel that benefit to my customers is worth the peering relationship.
Unless you were precient when you allocated your CIDR blocks, this means that you will not be able to aggregate your networks. Erik
I have a HUB in San Mateo. I decide that he's in the region of MAE-W and PACBELL and MAE-LA, but not the NXP in Phoenix. So, I accept routes from the folks at those NXPs, and only give the routes for my folks homed to my San Mateo HUB. My San Mateo Customers get to the folks at the NXP, and the other providers customers get to my customers CLOSE to the NXP in San Mateo. However, I don't have to backhaul them to another larger aggragation point, or to another NXP at which I hand off packets to their transit provider.
Benefit: I gain low latency transit to most everyone.
Drawback: It is technically challenging to create an automate system to regionalize and create appropriate filter lists.
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Perhaps this is a problem that's only challenging to the smaller folks, those of us w/out the nationwide DS3|OC3 networks. However, I do feel it's a worthy problem, and one that would benefit the NANOG community were it intelligently solved.
-a