> 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
