Hello Vince, That makes a sense.
Is this publicly documented somewhere? Damien Saucez Damien Saucez On 13 Aug 2012, at 22:18, Vince Fuller <[email protected]> wrote: >> As you certainly know, the mapping system has been migrated >> to LISP-DDT with success on 3/14/2012. As the migration was >> planed, we have decided to measure it! To do so, we used >> vantage points around the world in different network types (EID >> space, commercial Internet, research Internet...). These vantage >> points have measured for a period of about one month the >> mapping system. To do so, they have send a Map-Request >> for all the EID prefixes with lig, and this every 15 minutes. >> We expected to observe a big difference of delay and mappings >> between ALT and DDT. However, the result we obtain is that >> the change is not very significant. There is no particular loss >> of map-Request/Map-Reply during the transition and the delay >> is not significantly increased or reduced. However, we observe >> a much more variable delay now with DDT than before where >> delays were very stable with time. > > Hi Damien- > > Thanks for the interesting analysis. > > I'll offer a simple explanation for why lookup delay on the pilot network > has become more variable with the deployment of DDT: we have a somewhat > pathalogical configuration on the pilot network. In particular, the pilot > DDT topology includes regional DDT Map Servers in that can accept > registrations from every ETR in a region. The ETRs in the region, though, > are only configured to register to a subset of the DDT Map Servers in that > region. When a DDT Map Request is sent to a DDT Map Server that doesn't > have a particular ETR registered, a Map-Referral message with action code > "MS-NOT-REGISTERED" is returned, which causes the requestor to re-try to > a different DDT Map Server in the current referral set and results in > at least one additional DDT message round-trip-time. > > This "misconfiguration" is deliberate and is in place for internal testing > and configuration management purposes. Such a configuration would not be > used on a "real world" network so variable lookup performance on the pilot > network should not be considered representative of how things would work > in operational deployment. > > Hope this helps. > > --Vince _______________________________________________ lisp mailing list [email protected] https://www.ietf.org/mailman/listinfo/lisp
