Hi, Robin, I do share your good intention with this list of constraints.
But, again, I have some worry that perhaps this list will be falsely used to effectively reject most of proposals. Too many ideal assumption, perhaps with this list of constraints. Our patient is dying, in any moment. There's no way of saving him by surgery without causing pain, real severe pain. He won't voluntarily accept the pain. On Wed, Dec 2, 2009 at 8:26 AM, Robin Whittle <[email protected]> wrote: > Short version: I think constraints 1 to 7 are absolute. If the > best solution can't fully meet constraints 8, 9 and > 10, then maybe it could still solve the routing > scaling problem to a worthwhile degree. > > > Hi Noel, > > Thanks very much for this: > > >> http://www.firstpr.com.au/ip/ivip/RRG-2009/constraints/ > > > > I only have time for a quick skim of this (_way_ behind :-), but the list > of > > points generally looked pretty good to me. > > > > My only concern was that, in toto, the entire list might be the > equivalent of > > asking for a car that goes 400 KPH and gets 500 MPG (or whatever the > > equivalent is in kilometres per liter, sorry everyone in the rest of the > > world :-), i.e. we can't have all of them at the same time. So it might > be > > that we'd have to prioritize some as being more important than others. > > I think constraints 1 to 7 are absolute. Here are my thoughts on 8, > 9 and 10. > > > If the solution did not meet constraint 8, this means that could > still be highly attractive for many smaller networks which haven't > yet started using the unscalable approach to multihoming etc. (PI > space advertised in the DFZ), but would be either less attractive or > not attractive at all for those networks which already have their own > PI space. > > For instance, maybe the best proposal wouldn't be adopted widely by > networks with PI space, so the current number of DFZ routes would not > decline, but at least it would not grow as fast as without the > solution - and millions of smaller networks will get multihoming, > portability and TE on a scalable basis. > > > Constraint 9 - not compromising security, robustness or performance - > is a sliding-scale affair. Ideally there would be no compromise. > If the best we can do involves some compromise, then perhaps we can > still get wide enough adoption to solve the problem and provide > multihoming etc. for the large number of smaller networks which can't > get it now. > > There is an argument that smaller networks, which couldn't afford PI > space, even it was available (and it is for IPv6) wouldn't be > contributing to the scaling problem anyway, and don't have any > alternative for multihoming etc. than to adopt the scalable solution. > In that case, *maybe* they would accept some degradation in > security, robustness or performance. > > If and when IPv6 or some other addressing scheme becomes useful for > end-user networks as an alternative to IPv4, then I think it can be > assumed that the high costs of PI space, and of advertising it, which > are the pattern with IPv4 won't be replicated with IPv6 or whatever. > So in a broader architectural sense, beyond IPv4 (I am yet to be > convinced we ever will move beyond IPv4, except for cellphones), we > can't rely on the unscalable BGP approach to multihoming etc. being > "expensive". > > I think that any substantial perceived degradation (whether real or > not) will make it impossible to gain wide enough adoption as long as > the unscalable alternative is available to each end-user network. > > If the scalable solution offers second-rate performance compared to > conventional PA or PI space, or is perceived as being unsuitable for > large networks, then many small networks will avoid it - especially > smaller networks which plan to be larger in the future. > > > Constraint 10 is a sliding scale one too. Widespread voluntary > adoption could best be achieved if there was no need for any internal > router upgrades or replacements. However, for small networks, there > may be only one router and its cost may be so small as to present > little impediment to widespread adoption. For larger networks, > having to replace many or all internal routers - presumably expensive > ones - would surely be a barrier to voluntary adoption which would > make it much more difficult to wean these networks from their current > unscalable multihoming and portability arrangements. > > - Robin > > _______________________________________________ > rrg mailing list > [email protected] > http://www.irtf.org/mailman/listinfo/rrg > -- Regards, DY http://cnu.kr/~dykim
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