home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Columbia Kermit
/
kermit.zip
/
newsgroups
/
misc.19950929-19951130
/
000337_news@columbia.edu_Mon Nov 6 15:39:26 1995.msg
< prev
next >
Wrap
Internet Message Format
|
2020-01-01
|
4KB
Received: from apakabar.cc.columbia.edu by watsun.cc.columbia.edu with SMTP id AA00669
(5.65c+CU/IDA-1.4.4/HLK for <kermit.misc@watsun.cc.columbia.edu>); Mon, 6 Nov 1995 10:39:35 -0500
Received: by apakabar.cc.columbia.edu id AA02576
(5.65c+CU/IDA-1.4.4/HLK for kermit.misc@watsun); Mon, 6 Nov 1995 10:39:32 -0500
Path: news.columbia.edu!watsun.cc.columbia.edu!fdc
From: fdc@watsun.cc.columbia.edu (Frank da Cruz)
Newsgroups: comp.protocols.kermit.misc
Subject: Re: Maximum transfer speed
Date: 6 Nov 1995 15:39:26 GMT
Organization: Columbia University
Lines: 55
Message-Id: <47la7e$2g8@apakabar.cc.columbia.edu>
References: <Pine.HPP.3.91.951104220341.18624A-100000-100000@bluejay.creighton.edu>
Nntp-Posting-Host: watsun.cc.columbia.edu
Apparently-To: kermit.misc@watsun.cc.columbia.edu
In article
<Pine.HPP.3.91.951104220341.18624A-100000-100000@bluejay.creighton.edu>,
Psychos 'R Us <honge@creighton.edu> wrote:
: : : ...
: : : With MS-kermit... 3.14 patch 0 (21 May 1995)
:
You might want to try installing the patches - it might make a difference.
: : : ... the transfer rate is around 880cps...
:
: Right now, with all the control characters unprefixed, the transfer is
: exactly 1187cps at 14.4k -- which, in my opinion, little bit low. (: But
: it was an improvement from 880cps.
:
Right on both counts. Kermit can do much better than 1187 cps.
: For more FYI, I strictly do ZIPped download -- as such, I always try to
: turn off the hardware compression. With the Hayes Smartcom, I found it
: makes no difference in downloading speed whether the modem is going
: through Hayes ESP or a plain 8250-equipped built-in serial port.
:
: So from that fact, there are some heavy-duty overhead going on with
: kermit which I cannot put my finger on.
:
No, that's not it, because the same program can transfer data at much
higher rates. Most people consistently get 1600+ bps downloading ZIP files
on exactly the same type of connection, even using relatively low-end PCs,
and MUCH higher rates than that on uncompressed files. There is something
peculiar about your setup, and the most likely culprit is the ESP board.
A second suspect would be the modem. Measurements done here indicate that
turning off compression buys you next to nothing, but -- given the variation
in modem quality -- probably introduces some risks. So if I were in your
position I'd try a couple quick experiments:
1. Put the modem back to its default configuration (RTS/CTS, V.32bis,
V.42, V.42bis) and see what difference that makes. Obviously, make
sure Kermit is also set for RTS/CTS.
2. Hook your modem up to a regular serial port -- preferably a 16550A if
you have one, and take the ESP board out of the loop. Most modern
PCs have one or two serial ports on the motherboard and you probably
had to go into SETUP to disable them in order to install your ESP.
: I found the unprefix all does not
: always work. With 50-50 chance, the transfer will be aborted after 1st
: packet received with "unprefix all".
:
That means that there is at least one control character on your connection
that is not safe to unprefix. Control-character unprefixing is
intrinsically a tricky business. If it were safe to do it always, we'd
set Kermit up to do it by default. You have to hunt down the offending
control character(s) and prefix it/them. There are lots of hints about
this in the KERMIT.UPD file on the MS-DOS Kermit diskette.
- Frank