Lixia wrote: http://www.ietf.org/mail-archive/web/rrg/current/msg05231.html
that from 15 December to 15 February we will be discussing proposals, and after that writing the recommendation. In the two weeks to then, I would like to prompt a discussion of the constraints which apply to any solution to the routing scaling problem. I wrote about this in April and updated the text after some helpful and generally positive feedback: http://www.firstpr.com.au/ip/ivip/RRG-2009/constraints/ Does anyone agree with some or all of this? Can anyone suggest improvements to the text? Can anyone imagine a way the routing scaling problem - today's IPv4 problem or the same problem for IPv6 in the future - could be solved without being subject to constraints such as these? As far as I know, the solution needs to be voluntarily adopted by the great majority of networks which want or need multihoming, portability of their address space and/or inbound traffic engineering. We can't impose the solution. We need most - ideally all - networks which already, or in the future, want these things to voluntarily adopt the solution. Otherwise too great a proportion of the growing number of networks will continue to use the existing unscalable BGP techniques. Scalable routing beyond simply dealing with the needs of the sorts of networks which actually choose to use PI address space today: that is to provide one or more scalable techniques which a much larger number of networks, typically smaller ones, can adopt to achieve these goals. So the voluntary adoption constraints apply to both the sorts of networks which today have PI space, and also to a much larger number of typically smaller networks. The most obvious set of new adoptors of multihoming etc. would be businesses and organisations who wanted robust Internet connectivity to their offices, factories etc. via two or more physical links with different ISPs. The first link might be DSL or fibre and the other might just be WiMax or 3G or some other wireless technique - so it doesn't necessarily involve two cables. The aim may not be to maintain normal bandwidth, but to maintain enough connectivity for mailservers, SSL web servers, VPNs, video-audio conferencing etc. to continue business activities in the event the main link dies. I estimate an upper limit on the number of such networks by assuming that for every 1000 people, there is only likely to be one such organisation, typically a business, with sufficient motivation to get two links. If we assume a maximum population of 10 billion people, then that means there would be no more than 10,000,000 such networks. I assume that for most homes and businesses the reliability of their single DSL or wireless service is acceptable. As far as I know, the only scenario in which more than about 10M networks must be accommodated in the scalable routing system is where each mobile device has its own piece of address space, such as in: http://www.firstpr.com.au/ip/ivip/TTR-Mobility.pdf That could, in principle, mean billions of separate pieces of address space, such as 10 billion people each with a "cellphone". I suggest we leave mobility out of the discussion about voluntary adoption, since we don't need worry about mobility when solving the foreseeable routing scaling problem, and because if such mobility techniques are developed, there will be no problem with voluntary adoption since those techniques will be the only way to do it. There is no danger of cellphone users using existing BGP techniques to advertise their prefix in the DFZ. - Robin _______________________________________________ rrg mailing list [email protected] http://www.irtf.org/mailman/listinfo/rrg
