From owner-freebsd-hackers  Thu Oct 19 13:13:53 1995
Return-Path: owner-hackers
Received: (from root@localhost)
          by freefall.freebsd.org (8.6.12/8.6.6) id NAA00357
          for hackers-outgoing; Thu, 19 Oct 1995 13:13:53 -0700
Received: from Root.COM (implode.Root.COM [198.145.90.17])
          by freefall.freebsd.org (8.6.12/8.6.6) with ESMTP id NAA00352
          for <hackers@freebsd.org>; Thu, 19 Oct 1995 13:13:47 -0700
Received: from corbin.Root.COM (corbin [198.145.90.50]) by Root.COM (8.6.12/8.6.5) with ESMTP id NAA28685; Thu, 19 Oct 1995 13:13:44 -0700
Received: from localhost (localhost [127.0.0.1]) by corbin.Root.COM (8.6.12/8.6.5) with SMTP id NAA29801; Thu, 19 Oct 1995 13:07:26 -0700
Message-Id: <199510192007.NAA29801@corbin.Root.COM>
To: dennis@etinc.com (dennis)
cc: Joe Greco <jgreco@brasil.moneng.mei.com>, hackers@freebsd.org
Subject: Re: Bragging rights.. 
In-reply-to: Your message of "Thu, 19 Oct 95 16:03:35 EDT."
             <199510192003.QAA28405@etinc.com> 
From: David Greenman <davidg@Root.COM>
Reply-To: davidg@Root.COM
Date: Thu, 19 Oct 1995 13:07:20 -0700
Sender: owner-hackers@freebsd.org
Precedence: bulk

>>> 115k minus 20% async overhead.....Mostly I've heard about 70k or so for
>>> async links....If you don't think that 20-30% is worth an extra hundred
>>> dollars, then I guess you're entitled to that. It is, however, a
>consideration.
>>
>>Really??!!
>>
>
>>I had a 386DX/40 that routinely chatted with a 386DX/16 at 115200 (UUCP over
>>TCP/IP as a SLIP connection) and consistently hit > 10.5K/sec -- the number
>>ran around 11K/sec during non-peak times here at MEI, and I attribute the
>>difference to our network rather than any of the FreeBSD boxes involved (our
>>network traffic peaks at wire saturation at times, and never falls below
>>10%).
>
>90K still isn't 128k though??!!!!! So what does this have to do with ISDN,
>anyway? You realize, of course, that you're going through a Telephone switch
>digitally with ISDN.....

   Let me add a bit of sanity to this part of the discussion. 115200 baud async
will give you about 11.52Kbytes/second if you have no packet overhead. 115200
baud sync will give you 14.40Kbytes/second if you have no packet overhead.
   Why? Because we're talking bits - async is 8 data bits plus 1 start and 1
stop bit...10 bits. With synchronous serial, it's just 8 data bits. So sync
always has the potential to give you 25% more bytes throughput at the same bit
rate compared to async.
   Now with sync you'll also be running at a faster bit rate (128000bits/sec).
This is 16Kbytes/second. This is 38.9% faster.

-DG