Path: utzoo!utgpu!watserv1!maytag!xenitec!zswamp!root
From: root@zswamp.fidonet.org (Geoffrey Welsh)
Newsgroups: comp.dcom.modems
Subject: Re: Clarification on MNP4 and Everex 24+
Message-ID: <6819.27BE119B@zswamp.fidonet.org>
Date: Sat, 16 Feb 91 17:14:43 EST
Organization: Izot's Swamp BBS - Kitchener, Ontario

 >So, as I said, I don't understand the concern about buffer size.  
 >Large buffers do NOT increase propagation delay of small bursts of 
 >data.  Their primary negative impact is when you attempt to 
 >_cancel_ a _long_ transmission.

   That is precisely the issue at hand: what we're talking about is the 
flushing of the menu when the user hits a key.

   Worst case scenario: computer-modem interface locked at 19,200 (or 
38,400); menu is a full screen long (2K), and the modem can hold that much in 
a buffer.  A user calls at 1200 bps.  The menu is sent to the modem (for all 
intents instantly).  The user, familiar with the system, hits a key as soon 
as he sees the menu start.  However, the computer has already sent the menu 
out and is now proceding to act on the user's command... while the user 
watches 2K of menu stream out at 120 CPS, resulting in an annoying delay.

   That's why we like to keep buffers down on public access systems.

   Geoff
 

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