Subject: Re: Comments on draft-hain-templin-ipv6-limitedrange-02.txt

From: Dan Lanciani <[email-masked]>
Date: Fri, 3 Oct 2003 16:33:45 -0400 (EDT)

Fred Templin <[email-masked]> wrote:

|Brian,
|
|For the most part, agree with all of your points of clarification;
|thanks. One item for further discussion:
|
|Brian Haberman wrote:
|
|>>
|>> Long period of time, perhaps, but how long is difficult to
|>> quantify. Again, perhaps this is a question for the [BAKER]
|>> renumbering draft.
|>
|>
|> I think it is quite pertinent to this draft.  How long must an
|> address remain stable in order to satisfy this document's stability
|> goal? 
|
|
|I think this question is going to be very much dependent on
|the use case scenarios. For example, in the future we may see
|deeply-networked homes in which we will have long-lived
|sessions, such as playing a 3hr video between the DVD player
|and home theater system. Indeed, there may be "always-on"
|sessions such as the home-security system monitoring
|intrusion-detection sensors around the house.

I continue to believe that there is more to the notion of stability than
can be expressed by a simple time scalar.  Any measure of stability must
also take into account the ability of anyone other than the user/owner
of the address to force a change either directly or indirectly.  As soon as
you start to consider specific time frames as the primary characteristic of
stability you almost implicitly admit to a model where the control of the
address space (probably even in the short term) rests with a third party.
This in turn subjects the user of the address space to the technical problems
of the controlling entity and (perhaps worse) to the ability of that entity
to charge arbitrarily for continued stability.

There may be a second-order effect here, i.e., how long is a particular
stability time frame valid?  Today, my ISP might be willing to guarantee me
a minimum of 3 hours stability for $x.  But if next month it can change the
price for 3 hours of stability to 100*$x, was the address space ever really
stable even by the measure of a 3 hour time frame?

Ultimately I think stability is much closer to a binary property than to
something that can be measured in hours.  It may not (or may) be possible
to guarantee local address stability in the face of global change (e.g., to
a new version of IP), but to tie stability to almost anything of a smaller
scope is in effect to remove stability.  In particular, anything that depends
on the promise and competence of the user's service provider (which in turn
depends on the promises and competence of all the service providers up the
line) cannot realistically provide stable addresses.

There doesn't seem to be any obvious reason other than third-party control
to consider specific stability time frames.  Therefore, I suggest that the
only reasonable life for a stable address is, to a first approximation,
infinite.

				Dan Lanciani
				ddl@danlan.*com

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From: Fred Templin <[email-masked]>
Date: Fri, 03 Oct 2003 13:47:43 -0700

>only reasonable life for a stable address is, to a first approximation,

I must admit that this seems to follow from my use-case example
of the 24x7 home security monitoring.

Other opinions?

Fred
[email-masked]