Re: HTTP URL to support multiple naming

Mic Bowman (mic+@transarc.com)
Thu, 02 Feb 1995 08:04:45 -0500 (EST)


Message-Id: <9502021308.AA26718@mocha.bunyip.com>
To: kball@Novell.COM
Cc: J.P.Knight@lut.ac.uk, uri@bunyip.com
Subject: Re: HTTP URL to support multiple naming
In-Reply-To: Your message of "Wed, 01 Feb 1995 09:11:53 -0800."
             <9502011712.AA21574@ka.SJF.Novell.COM>
Date: Thu, 02 Feb 1995 08:04:45 -0500 (EST)
From: Mic Bowman <mic+@transarc.com>

> What if the server can be accessed via multiple transports or known via 
> multiple names in different naming systems.  Here you have multiple avenues 
> to the same host and the exact same document.  
> 
> What I dont want to see is a document reference (anchor) saying:
> 
> "click here if you can access this document from NetWare"
>  OR
> "click here if you can access this document via the Internet"
> 
> making the person make a choice of access methods, when they are 
> basically the same, HTTP (one over IP and the other over IPX).  Let
> the client chose, it knows how it is configured and what is available.

This situation seems to be coming up more often: URLs are often limited
in scope.  For IP-based networks, we get away with  pseudo-universality
of protocols such as ftp, http, and gopher.  However, we ran into 
problems defining the AFS url for precisely this reason.  AFS is great
for retrieving documents (or any "real" file system for that matter), 
but you can't put AFS urls in your documents because many clients cannot
resolve them.  An AFS proxy or gateway is not feasible because of the size
of the AFS space (sure, you could have multiple gateways, but which one
would you choose, AFS is awfully spread out).

Our solution was to provide "universal" access through http, use http
URLs in our documents, and provide AFS *clients* with a translation 
library that will convert http URLs into AFS URLs whenever possible.
In a sense, the translation library defines URL equivalence and preference.
Think of it as a client-side protocol independent identifier.

Your problem with IPX seems to be even more complicated.  There is no
*universal* protocol.  I dont see how you can get around the multiple
URL problem.

--Mic Bowman

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Mic Bowman
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Transarc Corporation
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