RE: [DNA] Comments on draft-shim-dna-proactive-00.txt

[Zhigao Chen <zgchen@psl.com.sg>]

> While I guess this isn't what's intended by the draft,
> I'd guess that there is enough potential uncertainty 
> associated with the AP information->Routing Information mapping to 
> treat the configuration information as a hint, rather than a 
> direct configuration.
> 
> Certainly in some environments, this hint is likely to be 
> quite reliable, but there's still work to be done to specify 
> what an adjacent AP's actual configuration is.
> 
> The other individual submission to make extensive use of AP 
> information essentially provides a more constrained problem 
> set. The devices in the APID draft are able to guess that the access 
> points provide the same configuration for this particular 
> wireless node, since they are already reachable from the 
> local L2 broadcast domain.
> 
Yes, in our APID-based DNAv6 solution it is hosts that maintain the
APID-address configuration mapping. In other words, a host only needs to
cache the configuration information from its default router(s) rather
than all routers.
 
> Incomplete information (association to an AP not in the list) 
> still is only a hint of change, as is association with a 
> particular AP (depending on where the APID config came from 
> ... (hosts?)).
> 
When a hint arrives, a host searches its APID Cache for the APID
extracted from the hint. If an APID is not found, i.e. not any
associated address configuration, the host reports the APID to routers
while doing or after doing router discovery. Routers in turn
disseminates the APID to hosts. So next time when the host attaches to
the AP, it can fast re-establish Internet configuration.
 
> In both cases, the configuration has to be checked.  
> 
> That may mean a single pair of messages direct to that 
> router, but I'd guess that this is fairly fast if the 
> configuration was correct (a likely case).
> 
> Greg
> 
> 

Regards,
Zhigao