[262] in Zephyr Mailing List
Re: Making Zephyr a standard
daemon@ATHENA.MIT.EDU (Greg Hudson)
Thu Mar 6 13:37:06 1997
To: Chris Hanson <chanson@mcs.com>
Cc: Zephyr <zephyr@MIT.EDU>
In-Reply-To: Your message of "Thu, 06 Mar 1997 07:12:57 CST."
<l03010d02af44722aae38@[206.31.151.87]>
Date: Thu, 06 Mar 1997 13:20:11 EST
From: Greg Hudson <ghudson@MIT.EDU>
> I keep thinking to myself that it'd be nice to see a Zephyr
> internet-draft or RFC, and eventually an Internet standard document
> on it.
Unfortunately, the Zephyr protocol is fundamentally flawed in multiple
ways:
* It uses a bogus encoding which multiplies the packet size by
a factor of 3 or so.
* It doesn't have any support for multiple authentication
types, and the authentication scheme is uses is
cryptographically flawed (des_quad_cksum() is not a good
hash).
* It fails to establish a long-lived context for
authentication, instead authenticating every packet the hard
way (the server has some caching hacks to make this cheaper,
but it's still a protocol flaw).
* It uses a host-specific rendezvous point, enforced by the
server, making it impossible for two people to use
independent client implementations on the same machine.
* It has none of the TCP fairness algorithms (unless you count
the exponential backoff I've added).
* It is exceptionally inefficient at transmitting large
messages, since it has no concept of windows and only
acknowledges entire messages.
In my opinion, what makes Zephyr worth maintaining outside of MIT is
zwgc, which has a fairly unique and hard to duplicate user interface
in the world of messaging software. It's kind of amusing that I would
come to this conclusion, since I personally don't even like
windowgrams and use a custom interface which makes Zephyr look rather
similar to IRC.
