Re: [DNA] Considerations for DNA Schemes with multiple Interface andLayer 2 Technologies

[JinHyeock Choi <jinchoe@samsung.com>]

Dear Pekka

> >>                 ... But in CDMA[7], a
> >>      mobile station can access two or more different base stations
> >>      simultaneously. In this case, a host can make a new link-layer
> >>      connection before an old link-layer connection is torn down.
> >
> > I hope that L2 can actually tell the packets apart.
> > If this is possible, then the implementation could present the packets
> > from the different links are arriving on different interfaces to IP.
> 
> I agree with Erik and others that the apparently cleanest way is
> to model the situation with distinct (virtual) interfaces, each
> corresponding to a wireless connection.

Agree. For a detailed operation, we may need a little more elaboration. 

> However, I am also wondering how often we need that in practise.
> As far as I've understood (which may be completely wrong), in the
> typical case the CDMA network models the whole base station network
> as a single link, with a single excess router.  OTOH, I have no
> idea whether soft handovers between operators is defined or not.
> If they are, then we probably need some care there.
> 
> Taking a slightly wider angle, we can imagine various anomalies
> like someone inadvertedly connecting two (wireline) LAN segments
> together.  That would (temporarily) create a similar situation.
> Hence, I'm afraid that we need to make the DNA scheme(s) robust
> against these kinds of situations.  However, my current opinion
> (subject to change) is that we should not worry too much about
> these kinds of situations, and it would be perfectly OK if it takes
> some more time to system to recover in such a situation.  In other
> words, if some hosts unnecessarily run DNA and autoconfiguration,
> that wouldn't be too bad.
> 
> Network operators have to live with the limits of technology
> anyway.  If our DNA effort results in a piece of technology that
> has a number of well documented limitations, that is OK, as long
> as the WG agrees on the limitations.

Agree.

Best Regards

JinHyeock