Subject: Re: definitions and use of "transparency" in the taxonomy

From: <[email-masked]>
Date: Wed, 5 Jan 2000 11:39:18 -0800

I am glad that this topic has come up -- I have been trying to access
the wrec mail archives for the past couple weeks in order to figure out
why "transparent proxy" was being used for an element that is neither
transparent (according to HTTP) nor a proxy (according to any traditional
definition of that term, including HTTP's).

HTTP has always used "gateway" to refer to an intermediary that was
not known to the client.  Yes, I know that gateway is also an overused
term, but the reason it was used is that all of the HTTP protocol
requirements are the same for HTTP-to-HTTP gateways as for HTTP-to-other
gateways, whereas they are considerably different from the protocol
requirements for a proxy which, by definition and accepted practice,
is an intermediary *chosen* by the client.

I don't buy the argument that "transparent proxy" is the common term
for this in the industry.  I am in this industry and yet I have never
heard that term used outside a wrec-related discussion, aside from its
use to indicate a non-transforming proxy of HTTP content within RFC 2616.
Given that the definition conflicts with that of "proxy" under HTTP and
therefore conflicts with the HTTP protocol requirements placed on a
proxy, I think it is foolish to use this term within specifications
that are supposed to be subsidiary to the HTTP standard.  It therefore
doesn't make sense for an IETF RFC to recommend that it be used within
the taxonomy.

A new term should be created; one that doesn't conflict with the
existing protocol specifications, and preferably one that doesn't
conflict with its meaning in English.  It doesn't have to match the
marketing terms -- it just needs to be consistent within the standards.

BTW, the mail archive at <ftp://cs.utk.edu/pub/wrec> has been
inaccessible for weeks.  Is there another one not listed in the
charter?

...........................................................
Roy T. Fielding, Chief Scientist        [email-masked]
eBuilt, Inc.                            tel:+1.949.609.0000
9401 Jeronimo Rd., Suite 100            fax:+1.949.609.0001
Irvine, CA 92618   USA                http://www.eBuilt.com
...........................................................

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From: Duane Wessels <[email-masked]>
Date: Wed, 5 Jan 2000 12:41:56 -0700

> inaccessible for weeks.  Is there another one not listed in the

www.wrec.org

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From: Patrick McManus <[email-masked]>
Date: Wed, 5 Jan 2000 14:55:16 -0500 (EST)

In a previous episode [email-masked] said...
:: 
:: I don't buy the argument that "transparent proxy" is the common term
:: for this in the industry.  I am in this industry and yet I have never
:: heard that term used outside a wrec-related discussion, 

first three sites I tried:

Alteon: "for use with transparent caches"
http://www.alteonwebsystems.com/products/cachedirector.shtml

Inktomi: "deploying transparent caching with inktomi's traffic server"
http://www.inktomi.com/products/network/traffic/tech/deploy.html
(there were 15 other documents with references to transparent caching
on inktomi's site)

Network Appliance: "Netcache: Transparent Caching"
http://www.netapp.com/tech_library/alt2.html
(there were 30 other documents with references to transparent caching
on netapp)

That's 3 for 3.. this is a very prominent term; like it or not. And I
don't.. but that's not the point of the taxonomy. What we can't do is
say that these things are "transparent" in the way the vendors who
created them want to imply.. and I think we do a good job of avoiding that.

(Altavista has 3260 pages with "+transparent +proxy" and 16,804 with
"+transparent +cache").. heck even CERN the home of the first httpd
has http://sunstats.cern.ch/mrtg/webcache.html titled "CERN-USA
Transparent Web Cache(s) Traffic".

-P

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From: Keith Moore <[email-masked]>
Date: Wed, 05 Jan 2000 14:56:19 -0500

> inaccessible for weeks.  

I don't know what the problem is; it works for me from my home net:.  

lust.indecency.org$ ftp cs.utk.edu
Connected to cs.utk.edu.
220 CS.UTK.EDU FTP server (Version wu-2.6.0(1) Sat Oct 30 21:31:07 EDT 1999) ready.
Name (cs.utk.edu:moore): ftp
331 Guest login ok, send your complete e-mail address as password.
Password:
230-Please read the file README.FTP
230-  it was last modified on Fri Apr  2 15:51:50 1993 - 2468 days ago
230 Guest login ok, access restrictions apply.
Remote system type is UNIX.
Using binary mode to transfer files.
ftp> cd pub/wrec
250 CWD command successful.
ftp> ls
227 Entering Passive Mode (128,169,94,1,62,61)
150 Opening ASCII mode data connection for file list.
mail-archive.1999-02
mail-archive.1999-03
mail-archive.1999-04
mail-archive.1999-05
mail-archive.1999-06
mail-archive.1999-07
mail-archive.1999-08
mail-archive.1999-09
mail-archive.1999-10
mail-archive.1999-11
mail-archive.1999-12
mail-archive.2000-01
226 Transfer complete.
ftp> get mail-archive.2000-01
local: mail-archive.2000-01 remote: mail-archive.2000-01
227 Entering Passive Mode (128,169,94,1,40,212)
150 Opening BINARY mode data connection for mail-archive.2000-01 (115418 bytes).
100% |*************************************|   112 KB    7.56 KB/s    00:00 ETA
226 Transfer complete.
115418 bytes received in 00:15 (7.41 KB/s)

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From: <[email-masked]>
Date: Wed, 05 Jan 2000 17:22:16 -0800 (PST)

> I don't know what the problem is; it works for me from my home net:.

FWIW, just tried it from here as well -- I was able to FTP the entire archive
with no trouble whatsoever.

				Ned

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From: Wojtek Sylwestrzak <[email-masked]>
Date: Wed, 5 Jan 2000 22:16:00 +0100 (MET)

> :: heard that term used outside a wrec-related discussion, 
[...]
> Transparent Web Cache(s) Traffic".

Exactly. Like it or not, this *is* the term in common use
and *this is* how the vocabulary gets (re)defined.
The goal of the taxonomy draft was to document the current
practice, not to impose new definitions or artificial terminology
even if it seems more appropriate for a reason.

--w

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From: Brian E Carpenter <[email-masked]>
Date: Wed, 05 Jan 2000 15:30:15 -0600

Can't resist, but I have trimmed the cc's somewhat...

Patrick McManus wrote:
...
>.. heck even CERN the home of the first httpd

Indeed. Firstly, that happened after I left CERN. Secondly, it was
that very "transparent" cache that taught me the hard way that
it wasn't transparent, when I was back at CERN earlier this year
trying to experiment with a toy diffserv setup across the Atlantic.

    Brian

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From: Keith Moore <[email-masked]>
Date: Wed, 05 Jan 2000 16:59:29 -0500

[followups trimmed]

> even if it seems more appropriate for a reason.

then why were people defending use of that term in another document
by citing the taxonomy draft?

I think the primary goal of a taxonomy document should be
to *establish* terminology so that everyone is using the same terms
to mean the same thing in subsequent discussions and documents.
i.e., to get everyone on the same page.

Keith

---

From: Wojtek Sylwestrzak <[email-masked]>
Date: Wed, 5 Jan 2000 23:13:30 +0100 (MET)

> i.e., to get everyone on the same page.

On the second thought, yes, the purpose is not just documenting
for it's own sake (or for future historians), but in order to have
a common understanding of the terminology as a basis for other works.

And this controversy proves, that this is indeed needed.

--w