Path: utzoo!utgpu!attcan!uunet!lll-winken!lll-tis!ames!elroy!cit-vax!mangler
From: mangler@cit-vax.Caltech.Edu (Don Speck)
Newsgroups: comp.dcom.modems
Subject: Re: TrailBlazer and UUCP
Message-ID: <7708@cit-vax.Caltech.Edu>
Date: 26 Aug 88 08:26:56 GMT
References: <12793@mimsy.UUCP> <27022@oliveb.olivetti.com>
Organization: California Institute of Technology
Lines: 20

In article <27022@oliveb.olivetti.com>, jerry@olivey.olivetti.com (Jerry Aguirre) writes:
> The practical problem comes up when you try to tell the modem what
> protocol to support.	You probably don't know when you are initializing
> the modem and dialing so you have to assume the 'g' protocol.  Later,
> UUCP will negotiate a protocol and decide that both sides support this
> new protocol.  Great!  Now how do you tell the Trailblazer that you
> changed your mind?

This problem can be sidestepped by making the new protocol upward
compatible.  For instance, fix the packet size negotiation bugs in
the "g" protocol, offer it as both the "g" and "G" protocol, and if
the "G" protocol is chosen by the remote uucico (indicating that it
too has the bug fixes), then negotiate a 128-byte or 256-byte packet
size.  This should be simple enough to implement that it could actually
happen.

N.B. Packet sizes larger than the tty input buffer won't decrease the
read() overhead any further, and big packets are inefficient for small
files, so you don't want to negotiate any higher than 256 bytes.

Don Speck   speck@vlsi.caltech.edu  {amdahl,ames!elroy}!cit-vax!speck