Re: [DNA-BOF] Do we need a separate DAD Problem Statement? (was Re:About Charter, DAD, and SEND)

[Pekka Nikander <pekka.nikander@nomadiclab.com>]

Bernard,

> If the "optimistic" traffic purely local, and the ARP/ND cache entry
> hasn't aged out yet, then it is possible that the host will be putting
> traffic onto the local link which isn't being received because the
> destination is actually off-link.  In this case, losses will continue
> until DNA completes and MIP handover occurs.  I'm not clear that this
> behavior is as "optimistic" as might appear at first blush, since the
> result is a backoff of RTO timers and a change in TCP state that might not
> occur if the host were not so "optimistic".

I agree that here may be a problem.  However, I also think that we
will need to change the TCP algorithms somewhat due to intermittend
connectivity anyway.  Hence, I also think that we can and should fix
this problem, and other TCP problems related to mobility handovers and
intermittend connectivity.  Although, that is not a task of the DNA WG.

--Pekka Nikander