Hi Robin, I think multi-homing in edge networks MUST support legacy hosts. Adding ISP uplinks to single-homed edge networks can be very beneficial. Taking an existing ISP uplink out of service would need more attention, but don't say this is impossible or not cost-effective. Let's say: it depends. More important: it can be decided site by site.
So I do not agree on: > For this reason, I think it would be impossible to successfully > introduce a host-based approach to multihoming Teco. > -----Oorspronkelijk bericht----- > Van: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Namens Robin > Whittle > Verzonden: maandag 24 november 2008 3:21 > Aan: RRG > Onderwerp: Re: [rrg] RACHH: the host-based solution - prepping the PR > team to sell it > > Hi Brian, > > You wrote: > > > It's become fashionable to assert that host based solutions > > are undeployable. I would like to recall that the model for > > rolling out shim6 is very clear - in MS-talk it's called > > "Updates are ready for your computer" - since *all* it requires > > is an IP stack upgrade. There are absolutely no changes for upper > > layers (except maybe a small tweak for SCTP code) and absolutely > > no changes for routers or ISPs. Of course, it's true that shim6 > > is not much use until a critical mass of users have installed > > that update, and it doesn't include TE features for ISPs. > > But the deployment model is o(OS programmers) in terms of > > significant cost. > > This only works for that subset of devices for which the operating > system is actively maintained and upgraded, for which the programmers > invest in adding SHIM6, for which automatic updates are possible and > for which the end-user of each device enables such automatic updates. > > This rules out older desktop and server operating systems, printers, > networking gear (Wi-Fi etc.), NAS boxes, probably lots of hand-held > devices which only have expensive mobile links to the Net and are not > so suitable for automatic OS updates etc. > > I don't see how this is a viable method of achieving the critical > mass required for multihoming based on SHIM6 to become useful. > Multihoming 10%, 50% or probably anything less than 95% of traffic > does not strike me as useful. Multihoming is only of value when it > works for essentially all traffic. > > For this reason, I think it would be impossible to successfully > introduce a host-based approach to multihoming - except perhaps over > a period of 15 years or so. There are so many devices which would > never be upgraded that it would take years - maybe a decade or more - > before they were thrown away and replaced by something modern with > the new system built in, that the people who did install the system > on all their hosts had 95% or more of their traffic properly > multihomed with the new system. > > Until that level is reached, there are only costs and risks in > installing the new system. There is no substantial benefit until > 95%, 99% or whatever of the other hosts in the world have been > upgraded too. > > > It's clear that once you ask for action by application > > programmers or non-routine action by end users, the costs > > become unthinkable. > > Yes. That is why I think trying to introduce a host-based scalable > routing solution is a non-starter. SHIM6 is not regarded as a > solution, and the only potentially viable host-based solutions > require changes to applications too, so they all use a new > hostname-based API. > > I think that LISP, APT, Ivip, TRRP and Six/One Router are all based > on the belief that a host-based solution is not the way to go. > > There are other, more fundamental, problems with a host-based > scalable routing solution - even if there was no problem > introducing it. I will write more about these in another message. > > > - Robin > _______________________________________________ > rrg mailing list > [email protected] > https://www.irtf.org/mailman/listinfo/rrg _______________________________________________ rrg mailing list [email protected] https://www.irtf.org/mailman/listinfo/rrg
