Subject: Re: comments on zeroconf requirements

From: Stuart Cheshire <[email-masked]>
Date: Mon, 16 Oct 2000 16:33:22 -0700

>- what is a timely manner

I think it is wise to deliberately leave "timely" unspecified, because it 
really does depend on the context. For situations where humans are 
waiting for results, a few seconds is generally "timely", but we should 
not rule out other situations where different constraints apply.

>It may well help to define a view that each participant has on the network.
>Each participant knows a set of IP addresses with a host name and a 
>physical address.
>One can then define consistency constraints on these views, like

I understand why these invariants are attractive, but it is hard to 
define them such that they relate to useful network properties. For 
example, the invariant "if A knows B then B knows A" sounds logical, 
until you consider a time server sending out periodic time updates via IP 
Multicast. Listeners know about the time server but the time server does 
not need to know about the listeners, nor should it, in the case where 
there may be countless listeners and just one time server, because that 
would be a pointless burden on the time server.

Stuart Cheshire <[email-masked]>
 * Wizard Without Portfolio, Apple Computer
 * Chairman, IETF ZEROCONF
 * www.stuartcheshire.org