Subject: Re: comments on requirements draft 04

From: Stuart Cheshire <[email-masked]>
Date: Tue, 15 Aug 2000 19:40:47 -0700

Some previous comments:

>I contend that a zeroconf protocol requires no external
>configuration, be it from burned in defaults, user configuration
>or via a network based configuration protocol (like DHCP).  That
>is not to say a host can't use these mechanisms to become
>configured, but in that case, the host is not using a zeroconf
>protocol to obtain its configuration parameters.

>After struggling with this for a long time, my conclusion is
>that the existents of a server isn't the issue. The issue is
>USER configuration. In other words, ease of use for the user is
>the only concern. The server may exist but if the user doesn't
>see it, it doesn't matter.

>I think Erik's got it just right - ZC means ABSOLUTELY no
>external configuration, *in particular* no fetching from
>routers, service repositories, etc.

I think we should say that no pair of ZEROCONF-compliant hosts, when 
properly connected together by a common physical link technology, should 
be prevented from communication merely by lack of additional 
infrastructure services.

There may be other things that prevent ZEROCONF-compliant hosts from 
communicating, such as not having the correct cable (this is why wireless 
is good), or their batteries being dead, or, in the case of two 
ZEROCONF-compliant printers, them simply having nothing interesting to 
say to each other -- but two hosts that are capable of useful 
communication should not be prevented from doing so because there is no 
DHCP server, or no DNS server, etc.

>a host using DHCP protocol for IP host config is zero-conf if the
>DHCP-server is also autoconfig.

>Using that principle, Zeroconfig means no human intervention
>ANYWHERE. If that requires a central box, then why isn't that OK
>- as long as the central box doesn't require human intervention.

When two strangers on a train meet, merely requiring that one of them 
remembered to bring the "central box" with them is too much human 
intervention, no matter how automatic the central box is. This is why I 
keep pushing to have the motivating example of two computers in an ad-hoc 
situation, to remind us of what we're doing.

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

---

From: Thomas Marshall Eubanks <[email-masked]>
Date: Wed, 16 Aug 2000 07:58:19 -0400

>  * Wizard Without Portfolio, Apple Computer

I didn't say that they were necessarily strangers.

Here is more or less what I had in mind - you buy a stereo. (The central
box.) It comes with (or you can buy additionally) smart speakers, which you
can plug in anywhere in the house, and they'll play from the stereo (maybe
using s wireless protocol). The stereo has all of the smarts, and the
multiple playback devices, and without it the speakers don't work.
Maybe it even acts as a DHCP server for them.
If that requires no human intervention, why isn't that zeroconf ?

                                   Regards
                                   Marshall Eubanks

   T.M. Eubanks
   Multicast Technologies, Inc
   10301 Democracy Lane, Suite 410
   Fairfax, Virginia 22030
   Phone : 703-293-9624
   Fax     : 703-293-9609

   e-mail : [email-masked]     [email-masked]

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