Hi Geoff, In the "Re: [rrg] draft-narten-radir-problem-statement-05.txt" thread http://www.ietf.org/mail-archive/web/rrg/current/msg06152.html
and in "BGP in 2009": http://www.potaroo.net/presentations/2010-02-01-bgp2009.pdf you presented some interesting research about DFZ activity. I think we are all greatly indebted to you for your long-term, BGP data gathering and for your detailed and continuing analysis. (Unfortunately, your mail client sends each paragraph as a single line, so the web-archives require a copy and paste to an editor in order to read them.) I agree with your slide 30 comment: BGP Scaling and Table Size As we get further into the IPv6 transition we may see: – accelerated IPv4 routing fragmentation as an outcome from the operation of a V4 address trading market that starts to slice up the V4 space into smaller routed units – parallel V6 deployment that picks up pace However, I think increasing growth in the number of IPv4 DFZ prefixes will increase, for the reasons you suggest, irrespective of however rapidly IPv6 is adopted. It is puzzling that there is continued growth in the number of IPv4 DFZ prefixes while the rate of updates remains static. Perhaps an increasing proportion of end-user networks and ISPs are keen to avoid being mentioned in your BGP Hall of Shame, AKA "The BGP Instability Report": http://bgpupdates.potaroo.net/instability/bgpupd.html I think your work is an excellent analysis of the most visible part of the routing scaling problem - analogous to the part of the iceberg which is above water: the burden on the DFZ control plane due to PI prefixes and due to unreasonably frequent updates to a small subset of all advertised prefixes. Keeping a lid on these problems is important. However, the harder-to-measure part of the routing scaling problem is the large number of end-user networks which want or need Portability, Multihoming and/or inbound TE but can't get them due to the costs and other barriers involved in gaining and advertising PI space in the IPv4 DFZ. Brian Carpenter recently suggested we should expect something in the order of 10^7 such networks: http://www.ietf.org/mail-archive/web/rrg/current/msg05801.html Firstly, I'd like to support the ten million estimate. Based on the projected world population of just under ten billion by 2050, that amounts to one enterprise per thousand humans, and that seems to be roughly what you find in the available data for developed economies (ignoring dummy companies and sole practitioners). I have made the same 10 million WAG on the same basis. This is not counting mobility, which could easily go to 3 or 5 billion hand-held devices in the foreseeable future, and perhaps as high as 10 billion in the next century. Some people exclude mobility from the routing scaling discussion, but mobility is prominently mentioned in the RRG's Charter. With the TTR Mobility architecture: http://www.firstpr.com.au/ip/ivip/TTR-Mobility.pdf a Core-Edge Separation architecture such as Ivip or LISP can be extended to provide a globally mobile IPv4 address or IPv6 /64 to mobile nodes, no matter how they connect to the Net (including behind NAT or on scalable "edge" addresses) - with no mapping update required when the MN gains a new address or access network. I just wrote a message "Recommendation suggestion from RW" which summarizes all the things I believe are important about scalable routing and the opportunity we have for making major architectural upgrades to IPv4 and IPv6. Its nearly 10k words - but I hope you would find it interesting. - Robin _______________________________________________ rrg mailing list rrg@irtf.org http://www.irtf.org/mailman/listinfo/rrg