Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10 5/3/83; site ulysses.UUCP
Path: utzoo!linus!decvax!harpo!eagle!mhuxt!mhuxi!mhuxa!ulysses!smb
From: smb@ulysses.UUCP
Newsgroups: net.news
Subject: Re: charging for path info
Message-ID: <572@ulysses.UUCP>
Date: Thu, 25-Aug-83 08:50:13 EDT
Article-I.D.: ulysses.572
Posted: Thu Aug 25 08:50:13 1983
Date-Received: Fri, 26-Aug-83 07:36:38 EDT
References: <180@decvax.UUCP>
Organization: Bell Labs, Murray Hill
Lines: 20

The hard part isn't calculating optimum paths, it's collecting good data.
I know; I've tried it.

First, most sites do not respond to requests for info.  Those that do
typically ignore the suggested format, meaning that you have to do a lot
of editing.  There are also conflicts to be resolved.  For example, some
university will say that some site polls them hourly, but the polling site
denies that it's more than daily.  New sites come on, old ones drop off.
Automated schemes depend on co-operation -- will all sites install the
program you write?  Probably not.  Even if they do, what's their source
of data?  L.sys files are notoriously full of non-host info.  For example,
some sites have other time-sharing machines listed, and a 'cu' variant
that dials up the machine, logs them in, etc.  I once wrote an automated
line loopback tester -- but I used a lot of uucp code, including L.sys,
to establish the link and fire up the remote end (for cases when one
couldn't put the line into loopback mode via hardware).  Then there are
the sites that don't forward mail, or that use something other than '!'...


		--Steve