*BSD News Article 21924


Return to BSD News archive

Path: sserve!newshost.anu.edu.au!munnari.oz.au!foxhound.dsto.gov.au!fang.dsto.gov.au!myall.awadi.com.au!myall!blymn
From: blymn@mallee.awadi.com.au (Brett Lymn)
Newsgroups: comp.os.386bsd.questions
Subject: slip performance (was Re: ed0: device timeout, freebsd cslip )
Date: 05 Oct 1993 23:03:08 GMT
Organization: AWA Defence Industries
Lines: 49
Message-ID: <BLYMN.93Oct5170310@mallee.awadi.com.au>
References: <1993Oct3.020559.16808@zen.void.oz.au> <CECt8C.29o@Colorado.EDU>
	<JKH.93Oct4083135@whisker.lotus.ie> <CEDnEn.D9r@usenet.ucs.indiana.edu>
NNTP-Posting-Host: mallee.awadi.com.au
In-reply-to: pitts@bigbang.astro.indiana.edu's message of Mon, 4 Oct 1993 14:39:58 GMT

>>>>> On Mon, 4 Oct 1993 14:39:58 GMT, pitts@bigbang.astro.indiana.edu (Jim Pitts) said:
Jim> Nntp-Posting-Host: bigbang.astro.indiana.edu

>
>2.  Using the com, rather than the considerably faster sio driver.
>
>	   I know I'm using the computing equivalent of a 1 inch penis,
>	   but .6k/sec CSLIP with recognized 16550A UARTs, ~5 MIPS and 
>	   a perfectly clean phone line?  I think I could get better 
>	   throughput by using tree sloths as the transport layer.
>
Jim> Boy, you are not far off on that one.  Is there a good reason you are not
Jim> using the sio driver?  I get 1.4-1.9K/sec from my 14.4 (USR Sportster) using
Jim> ftp/16550A/sio drivers.

Could be because it works, apparently there are some problems with
sio, most notably with handling of hardware flow control.

Jim> The compression features of 14.4K modems can actually HURT your transfer
Jim> rate on gzipped files that are ALREADY compressed.  Remember that your
Jim> modem has to spend time compressing files before it sends them (that
Jim> is how it gets to the speeds it does at some level).  If there is
Jim> little redundancy in the data you are transmitting, this can slow you
Jim> down a good bit.

Depends on the modem, if you have a modem that only does MNP 5 then
this is true since MNP 5 will try to compress the uncompressible and
actually end up expanding the data.  A v.42bis modem will not do this,
it will transmit whatever is smaller.

Jim>  I would suggest if you want to compare to other peoples
Jim> numbers you provide the transfer rates for:

Jim> 	1.  gzip'ped files (packed binaries).

about 1k/s

Jim> 	2.  ASCII text files.

ranges from the sublime to the ridiculous but up near 2K/s

Jim> 	3.  Executable binaries (non packed binaries).

about 1.3K/s (I mostly ftp gif and jpg files ;-)

All this on a 0.1 + 0.2.4 + cgd com drivers + 16550

--
Brett Lymn