On Jun 21, 2007, at 11:03 AM, Olivier Bonaventure wrote:
Noel,> From: Robin Whittle <rw@firstpr.com.au> > Geoff Huston has a new article "Damping BGP":> "... the busiest 1% of prefixes responsible for 24% of the routing> updates for the month."While I agree that whatever's causing this ought to be fixed, there are somepoints we need to not lose sight of.First, fixing this would be a *one-time* improvement in the growth curve for the update rate (versus long-term time). I.e. you'd see a flat spot (or adrop) in the curve, after which it would resume its previous growth.Second, 25% is not peanuts, but it's also not an order of magnitude, and eliminating these wouldn't get us into a whole new operating region. I don't know what the current growth rate for BGP updates is, but if it's anything like the growth rate of the table itself (as one might reasonably assume itis), 25% is not a long calendar time.Again, it ought to be fixed, but let's not kid ourselves that this is thesolution to our problems.I completely agree with you. If the RRG wants to reduce the path hunting problem, a better approach would be to look at BGP extensions like EPIC that allow routers to avoid transmitting unnecessary messages. This is a longer term approach than tuning the damping mechanisms but would probably be very useful. Another longer term direction could be to develop interdomain routing protocols that are not entirely based on path vector like BGP. A possible approach is HLP.EPIC is described in Jaideep Chandrashekar, Zhenhai Duan, Zhi-Li Zhang,Jeff Krasky, Limiting Path Exploration in BGP, IEEE INFOCOM 2005, http://www.cs.fsu.edu/~duan/publications/epic_infocom05.pdf
HLP is described inL. Subramanian, M. Caesar, C. Tien Ee, M. Handley, M. Mao, S. Shenker, I. Stoica, “HLP: A Next Generation Interdomain Routing Protocol,” SIGCOMM’05. http://portal.acm.org/citation.cfm? id=1080091.1080095
or http://www.sigcomm.org/sigcomm2005/paper-SubCae.pdf which seems to be publicly available. Regards Marshall
Olivier -- http://inl.info.ucl.ac.be , Universite catholique de Louvain, Belgium -- to unsubscribe send a message to rrg-request@psg.com with the word 'unsubscribe' in a single line as the message text body. archive: <http://psg.com/lists/rrg/> & ftp://psg.com/pub/lists/rrg
-- to unsubscribe send a message to rrg-request@psg.com with the word 'unsubscribe' in a single line as the message text body. archive: <http://psg.com/lists/rrg/> & ftp://psg.com/pub/lists/rrg