Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.1 6/24/83; site down.FUN
Path: utzoo!watmath!clyde!burl!ulysses!allegra!princeton!down!honey
From: honey@down.FUN (code 101)
Newsgroups: net.bugs.uucp
Subject: Re: UUCP sitenames / Sys V fix
Message-ID: <288@down.FUN>
Date: Fri, 31-Aug-84 10:39:50 EDT
Article-I.D.: down.288
Posted: Fri Aug 31 10:39:50 1984
Date-Received: Sat, 1-Sep-84 12:35:53 EDT
References: <25@harvard.ARPA>
Organization: The Official Fun Machine of Princeton Univ. EECS
Lines: 38

There are two aspects to the truncated sitename problem; your
characterization of the lesser of them is on the mark.  However,
the other is by far the more serious of the two.

Suppose my site talks to sdchema and sdchemb.  Work files spooled for
these sites are of the form C.sdchemaX1234 and C.sdchembY5678.  I.e.,
the work file is of the form
	C. + sitename + grade + sequence
where grade is one byte and sequence is four bytes.  This leaves seven
bytes for the sitename; anything longer is truncated.

The horrible mistake made in System V UUCP was the decision to use
two grade characters*, leaving but six digits for the host name
prefix.  This forces the above work files to be C.sdchemXA1234 and
C.sdchemYA5678.  Consequently, it is impossible for uucico to
distinguish between work files spooled for sdchema and sdchemb.

There seems to be no satisfactory resolution of this problem; while it
is likely that most System V sites will ultimately run honey danber
(which, as you may have guessed, reverts to the seven letter standard),
there will *always* be a number of sites that don't upgrade.  And this
number may be significant, since lots and lots of companies have ported
System V to obscure machines and don't feel pressured to upgrade.

	Peter

* The appearance of the second grade character was motivated by a
   perceived need to reduce the number of times sequence numbers are
   retrieved (and the concomitant lock contention).  Other versions of
   UUCP, notably 4.2BSD and honey danber, achieve the same goal in
   clever ways**.

** The mechanics can be found in gename.c (pronounced ge'-nam-ee-dot-c).
   It's interesting to note that 4.2BSD UUCP and honey danber use
   radically different techniques to effect the same goal.  Even so,
   they were written by the same person***.

***  Heh heh.