🚀 go-pugleaf

First the big question: how do you get a vendor to follow the standard rather
than some broken product(s), when the broken stuff works for their other
customers?

Here's the story:  Sybase's client-server system provides a dbcancel function
to stop the execution of a database query that you change your mind about
(in case you said "select * from everything" and you don't have all day).
They implement it using TCP urgent data; but RFC1122 fixed an off-by-one
error in the definition of the urgent pointer in RFC793.  This means that
an implementation of TCP according to the new spec won't interoperate with
an implementation that follows the old RFC if they use urgent data.  In fact,
the connection will generally hang irrecoverably.  This is ungood for
production work.
	At Compaq, we have an environment that induces us to use for our
database clients FTP software's PC/TCP, which precisely follows RFC1122.
But we also have a relation with SCO that leads us to use their dialect
of Unix on our servers, and their TCP/IP implementation is "mostly compliant"
to 1122, where "mostly" excludes TCP urgent data.  As a consequence, we can't
use any software that utilizes this feature of the protocol.
	SCO claims that they do this because "everybody else's" implementation
also follows the broken part of RFC793 (namely ATT SysVr4, SunOS, Sun PC/NFS,
ISC 386/ix, etc.).  They also say they don't intend to fix the problem until
about 3 versions from now, say in 1994.

Several questions are now in the air:
- are we going to be stuck on this for 3 years?
- is this off-by-one problem really so difficult that it takes 3 years to fix?
- what implementations of Unix do TCP urgent data the right way?
- are there any implementations on any platform that can do it both ways?

	- George

George McKee				gmckee@cpqhou.se.hou.compaq.com
Systems Programmer			uunet!cpqhou!gmckee
Information Management			Voice: 713 378 7991
Compaq Computer Corporation		Fax:   713 374 1740
P.O. Box 692000 M010301			disclaimer: facts are facts,
Houston, TX 77269-2000			Compaq is Compaq, my opinions are mine.
...and a fine how-de-do to anyone who can derive this from quantum mechanics.