North American Network Operators Group|
Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical
Re: a radical proposal (Re: protocols that don't meet the need...)
PJ> Date: Wed, 15 Feb 2006 19:02:11 +0000 (GMT) PJ> From: Paul Jakma PJ> > Of course not. Let SBC and Cox obtain a _joint_ ASN and _joint_ address PJ> > space. Each provider announces the aggregate co-op space via the joint PJ> > ASN as a downstream. PJ> PJ> This is unworkable obviously: Think next about SBC and (say) Verizon No, it is not unworkable. Think through it a bit more. Although the problem is theoretically O(N^2), in practice it is closer to O(N). Note that _routing itself_ is theoretically an O(N^2) problem. Do we say that it is "unworkable obviously"? No. PJ> customers, then what about those with Cox and Verizon, then SBC/Cox/Verizon. PJ> etc. Yes, one ASN is required per cooperating pair. Just how many pairs do you think there are? Now compare with the number of leaves that [would [like to]] dual-home. If you have 100 providers, each cooperating with every single one of the others, that's 100 * 99 / 2 = 4950 different ASes. Noticeable, but still a long way from 4-octet ASN territory. And guess what? Each downstream would need its own ASN otherwise; this is just one ASN per cooperating pair. How many transit ASes are there? And will each one share a downstream with all of the others? http://www.caida.org/analysis/routing/ I'll hazard a guess that a transit cooperates with, on average, no more than five different other transits. Ergo, linear scaling. The biggest problem is when customer's link to provider A goes down and inbound traffic must flow through provider B. This necessitates some sort of path between A and B where more-specifics can flow. Eddy -- Everquick Internet - http://www.everquick.net/ A division of Brotsman & Dreger, Inc. - http://www.brotsman.com/ Bandwidth, consulting, e-commerce, hosting, and network building Phone: +1 785 865 5885 Lawrence and [inter]national Phone: +1 316 794 8922 Wichita ________________________________________________________________________ DO NOT send mail to the following addresses: [email protected] -*- [email protected] -*- [email protected] Sending mail to spambait addresses is a great way to get blocked. Ditto for broken OOO autoresponders and foolish AV software backscatter.