Path: utzoo!attcan!uunet!mailrus!iuvax!watmath!looking!brad
From: brad@looking.on.ca (Brad Templeton)
Newsgroups: comp.org.usenix
Subject: Re: USENIX Board Studies UUCP
Keywords: protocols
Message-ID: <51949@looking.on.ca>
Date: 24 Nov 89 03:21:54 GMT
References: <287@usenix.UUCP> <1624@crdos1.crd.ge.COM> <1989Nov16.182104.23746@utzoo.uucp> <92074@pyramid.pyramid.com>
Organization: Looking Glass Software Ltd.
Lines: 22
Class: discussion

Rather than SLIP or uucp/g, it is far easier to write a protocol that
supports 'stacked' multiple transmissions.   Yes, arbitary multiple sessions,
as found in X.25 and IP are nice, but it's complex to implement and not
as efficient as stacked transmissions.

If you allows stacked multiple transmissions, then a higher priority
transmission can interrupt a low priority one.  The low priority one is
suspended until the higher one is done.

Thus a long file transfer can be interrupted by a higher priority transfer
of a short file or a news batch, and a mail message can interrupt these,
and a 'msg' or 'finger' request etc can supersed that.

This is very easy to implement, and good for all lines that don't expect
to run dialogues like login sessions or SMTP.  ie. transaction systems, the
kind you want over phone lines.

Ease of implementation is important.  We want this to come up on a lot
of systems, and if we tell everybody to implement IP or X.25, it just makes
it less likely.
-- 
Brad Templeton, ClariNet Communications Corp. -- Waterloo, Ontario 519/884-7473