> From: Robin Whittle <r...@firstpr.com.au> > Debating various aspects of LISP with Joel
Err, 'Noel'. > As far as I know, no-one in the main LISP team has developed a better > mapping system or suggested that one should or will be developed > ... > Please mention what this is, with references. After a great deal of work (extensive detailed simulation, etc), a paper has been written and submitted to a conference, but it's not public quite yet. Hopefully it will be public Real Soon. (Sorry, but it's not a paper I had anything to do with, so I don't feel I can say more than that - I merely commented privately on a draft.) Work has started on a spec, but again it's still not public, alas. However, the Map-Resolver/Map-Server interface to the mapping system, which allows use of different mapping system 'back-ends' is already fully public. >> In light of that, you might want to move the ALT discussion to the >> end, and clearly separate it from the discussion of LISP as a whole. > Since I don't yet know what the alternative is, my critique is of LISP > with ALT. Understood, but that does not vitiate either half of the suggestion above. After all, as I pointed out, the mapping service interface _is_ already specified. > I know there is a view that the delays which can easily be foreseen in > LISP-ALT are not significant enough to prevent it being adopted widely > enough to solve the routing scaling problem. I and some other people > disagree with this viewpoint. Pointing out the delays is fine. It's the flat assertion that this will produce a certain result out in the world I'm questioning. E.g. have you gone around to a significant subset of ISPs/large-content-providers, and asked them if these delays are unsupportable? If not, then the statement is merely your subjective, personal, opinion. > With a global query server network, the delay in getting mapping will > frequently be longer than this, since the answer has to come from the > other side of the planet, which typically takes 350 to 400ms. There have been discussions on caching mappings in the Map-Resolvers, which will remove this delay for 'popular' destinations. > I assert that any global query server system for mapping lookups will > involve a significant performance degradation - sufficient to affect > the experience of users. I also assert that even if the measured impact > on end-users is minimal, the perception of this reduced performance > will significantly reduce the chance of widespread voluntary adoption > to a degree which threatens the ability of the system to solve the > routing scaling problem. And I assert the contrary. Arbitrary assertions, with no supporting evidence, have no place in this document. > Every time an LISP-MN gets a new RLOC address ... then all the ITRs in > the world need to suddenly change their mapping to the new RLOC address. No, only the ones the LISP-MN is currently communicating with. Why would some ITR which has never communicated with the MN, and never will, need the updated mapping? Noel _______________________________________________ rrg mailing list rrg@irtf.org http://www.irtf.org/mailman/listinfo/rrg