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Re: IPv6 end user addressing
From: Owen DeLong <owen () delong com>
Date: Wed, 10 Aug 2011 21:03:56 -0700


On Aug 10, 2011, at 7:45 PM, Mark Newton wrote:


On 11/08/2011, at 8:42 AM, Owen DeLong wrote:

I suppose that limiting enough households to too small an allocation
will have that effect. I would rather we steer the internet deployment
towards liberal enough allocations to avoid such disability for the
future.


I see the lack of agreement on whether /48 or /56 or /60 is good for a
home network to be a positive thing.

As long as there's no firm consensus, router vendors will have to implement
features which don't make silly hard-coded assumptions.

Yes and no. In terms of potential innovations, if enough of the market chooses
/60, they will hard code the assumption that they cannot count on more than
a /60 being available into their development process regardless of what
gets into the router. Sure, they won't be able to assume you can't get a /48,
but, they also won't necessarily implement features that would take advantage
of a /48.

Innovation will still happen, features will still be implemented, we'll
still climb out of the NAT morass.  But we'll do it with CPE that allows for
a richer spectrum of variation than we would if we just said, "Dammit, /48 for
everyone."


We'll climb out of the NAT morass, yes. That's not innovation, that's recovery.

Innovation of products that are capable of building significant automatic
partitioning and hierarchy will not happen if ISPs choose not to supply
enough addresses to facilitate use by a critical mass of customers. No router
vendor is going to spend development resources building features that
their customers will want but be unable to use because their ISP says no.

It's all good.  At this stage of the game, any amount of "moving forward" is
better than staying where we are.


True, but, there are degrees of better. Moving forward on a slightly wrong
path is better than moving forward on a radically wrong path. Both are
better than standing still or moving backward.

If you try to get to a point that is 010º from your current position and 60 miles
in front of you, it's better to travel 015º than 350º. Both are way better than 060º
and 060º is way better than 090º which is still better than 180º.

However, 015º will be slightly off until you basically pass your destination.
However, 350º will have you fairly far off by the time you pass your destination.
Obviously, 060º will never bring you very close to the destination, even if you will
        start out getting slightly closer to it.
Even 090º will bring you closer to your destination for a little while before you
start getting farther away again.

It ends up looking like this:



The thin lines are construction lines to show the computation of the closest point (the point where
a line perpendicular to the course chosen intersects the destination waypoint). The black dots
represent the actual closest points.

Obviously, the closest point is closer the less off-course you are. However, more interestingly,
the more off course you are, the sooner you reach a point where you are no longer heading
towards, but, away from your destination. Obviously for lines 90º to 270º off of the desired
course, you begin heading away immediately. (note that the 90º line above is only 80º
off course).

Perhaps far more than most of you wanted to know about navigation, but, at least worth
considering when we think that all forward movement is good forward movement.

Owen


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