Subject: Re: How to overcome this WG's flailing

From: Stuart Cheshire <[email-masked]>
Date: Thu, 17 Aug 2000 15:21:00 -0700

>This, in a nutshell, illustrates the problem that this WG seems to be 
>having.  We're flailing about, trying to define what "zeroconf" means, 
>but without a firm basis for forming such a definition.

Thanks Ross. You are right about this.

The key thing we need to establish is that "zeroconf" is not just a 
marketing buzzword. It doesn't mean, "Make my Cable Modem easier to use."

Anything communicating over the global Internet is by definition not 
zeroconf. Zeroconf means still being able to perform IP communication 
when you're NOT connected to any external infrastructure. I agree that 
many things about IP and the Internet could be made easier, but this WG 
is not out to fix every single problem with IP. The charter of this WG is 
to make IP usable when there is no external infrastructure. The charter 
specifically limits zeroconf to internetworks with at most ONE router. 
The Internet, last time I checked, had more than one router. (And don't 
make the mistake of claiming that you can have a home internetwork with 
one router that's "connected" to the Internet. Once you connect two 
internetworks, they're not separate any more. That's like pouring a cup 
of coffee into the sea and claiming that you still have a cup of coffee. 
If you're connected to the Internet then you're part of it, and the 
aggregate internetwork as a whole has more than one router.)

I will try to work out a clear statement of what I think the definitions 
of a zeroconf protocol and a zeroconf host should be.

Stuart Cheshire <[email-masked]>
 * Wizard Without Portfolio, Apple Computer

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From: Robert Elz <[email-masked]>
Date: Sat, 19 Aug 2000 20:38:52 +1000

Date:        Thu, 17 Aug 2000 15:21:00 -0700
    From:        Stuart Cheshire <[email-masked]>
    Message-ID:  <[email-masked]>

  | The charter of this WG is 
  | to make IP usable when there is no external infrastructure. The charter 
  | specifically limits zeroconf to internetworks with at most ONE router. 
  | The Internet, last time I checked, had more than one router.

If that is to be the limit of what this WG is to achieve (as opposed to
just being a part of the result), then you might as well close it down now
and all go away.

In the not too distant future (quite possibly before this WG has decided
on what it is supposed to be achieving at the rate it is going) the
internet, and access to it, is likely to be more or less ubiquitous.

The "strangers on the train" won't just be talking to each other, the train
will be providing internet access.   It has to for the whole thing to be
worthwhile.  It might be reasonable for members of this group to happening
to be travelling by the same train (or plane) and want to be able to
communicate with each other - though only one train/plane in a hundred
is likely to have such a group aboard.   More likely, on an average train/plane
you may find a few people willing to join some multi-user game, and so be
content to be connected to each other, and no-one else.   But all the other
travellers are going to want to access the stock prices, news reports,
their e-mail (messages), internet radio, ...

For that, they're going to have to connect themselves to the internet,
and the tains and planes, will start providing that connectivity sometime
not too far away.   Similarly houses without internet connectivity will become
about as common as houses without phones.

So, if you're planning to restrict yourselves to the fringes, and not solve
any useful problems, I see no point in this WG existing.   It needs to be
able to handle zeroconf hosts connecting to a (probably configured by someone
else) network, as well as the less likely case of an ad-hoc network forming
that is connected to nowhere.

kre

ps: if appletalk is the model, then the "zero" in zeroconf needs to be treated
quite liberally - a truly zero configured appletalk network is useful for
almost nothing at all (sure, it exists, but without someone configuring some
services on it, there's not a lot you're able to do).

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From: RJ Atkinson <[email-masked]>
Date: Sat, 19 Aug 2000 09:22:10 -0400

>just being a part of the result), then you might as well close it down now

        Disagree.

>their e-mail (messages), internet radio, ...

...and existing methods (e.g. DHCP, Router Discovery, Service Location)
already address that scenario.  If there are unresolved issues, then
that would be fine work, but possibly in a different WG.

>able to handle zeroconf hosts connecting to a (probably configured by someone else) network, as well as the less likely case of an ad-hoc 
>network forming that is connected to nowhere.

Disagree.  

        Other techniques (e.g. DHCP, Router Discovery, Service Location)
work fine for a network where someone has done some configuration.  

        To the extent folks think there are open issues with the scenarios
that kre has outlined, maybe there needs to be a separate WG
to look into those issues.

Ran
[email-masked]

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From: "Bernard Aboba" <[email-masked]>
Date: Sat, 19 Aug 2000 06:11:47 -0700

>Any IP internetwork with a router. If you've installed a router, then it
>might as well include a DHCP server to assign addresses, and however
>automatic or easy to use that might be made, the DHCP protocol already
>exists and the Zeroconf WG doesn't need to reinvent it.

You're right that re-inventing DHCP isn't necessary. However, I wouldn't
conclude from that there is no work left to be done. Just because protocols
exist that can be re-used (e.g. DHCP, spanning tree) does not mean that a
profile exists on how to use those protocols in a way that achieves
our objectives. It is also sometimes useful to have a framework
document that can explain how a number of disparate pieces work
together coherently.

I would suggest that it might be appropriate for ZEROCONF to
work on that framework document. This might enable the
various WGs handling elements of the problem to understand
better how ther work inter-relates.

In general, one of the reasons for having a working group is that
it creates a community of people interested in solving a problem.
To some extent the current approach risks segmenting the problem in a
way that this energy cannot be fully harnessed.

>that is connected to nowhere.

When listening to presentations about adhoc networks,
I often find myself wondering whether the scenarios really make sense. 25
people in a conference room only wanting to talk to each other and never to
connect to the Internet to read mail or browse the web? Nowadays when
I'm in meetings, it seems like people spend most of their time reading
email or web browsing, so much so that I sometimes wish they would stop.
My sense of what motivates so much interest in ZEROCONF isn't so much
the ability to reinvent the functionality of AppleTalk and NetBEUI (with
all its warts) but rather the ability to achieve the ease of use of
those protocols AND also gain all the advantages of Internet connectivity.

In terms of the set of work that needs to be done to enable
Internet-connected
scenarios, here is what I think needs to be done:

1. I would suggest that the behavior of mini-DHCP/DNS proxies
needs to be defined. That might be done elsewhere (like DHC WG
or DNSEXT) but I think it needs to happen.

2. There is a need for work on security in adhoc and home networks.

3. There may be work needed with respect to adhoc networking and
implementation of bridging protocols on hosts.