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1994-11-13
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Date: Tue, 21 Jun 94 04:30:02 PDT
From: Advanced Amateur Radio Networking Group <tcp-group@ucsd.edu>
Errors-To: TCP-Group-Errors@UCSD.Edu
Reply-To: TCP-Group@UCSD.Edu
Precedence: Bulk
Subject: TCP-Group Digest V94 #125
To: tcp-group-digest
TCP-Group Digest Tue, 21 Jun 94 Volume 94 : Issue 125
Today's Topics:
IP-TNC, the beginings? (2 msgs)
Standard Digital Radio Interface
Send Replies or notes for publication to: <TCP-Group@UCSD.Edu>.
Subscription requests to <TCP-Group-REQUEST@UCSD.Edu>.
Problems you can't solve otherwise to brian@ucsd.edu.
Archives of past issues of the TCP-Group Digest are available
(by FTP only) from UCSD.Edu in directory "mailarchives".
We trust that readers are intelligent enough to realize that all text
herein consists of personal comments and does not represent the official
policies or positions of any party. Your mileage may vary. So there.
----------------------------------------------------------------------
Date: Mon, 20 Jun 1994 14:53:01 -0400 (EDT)
From: DJ Gregor <dgregor@bronze.coil.com>
Subject: IP-TNC, the beginings?
To: nos-bbs@hydra.carleton.ca
The type of IP-TNC (or PPP-TNC) that I would like to make right now is a EPROM
that goes into your standard TAPR-2 clone. Most people that are running KISS
are running on a TAPR-2 clone, and that is what I would like to have something
better for *right now*. (oh, I wouldn't consider anything like what Barry
suggested a Terminal Node Conroller, something like that should be called a
packet switch.)
I have been thinking about an IP-TNC for a while. When David Kelly, N4HHE
suggested it on the nos-bbs list, I decided to start. I am in high-school and I
am off for the summer, so I have _plenty_ of time to work on it.
What I would like to start with is change the KISS interface to SLIP and put
ARP in the TNC. Then, we can figure out something to do with AX.25 packets,
either send them to the host on a UDP port, or maybe a Telnet session or some-
thing like that. Eventually, I would like to have the TNC able to do routing;
instead of having a node stack of NET/ROM TNCs, have a node stack of IP-TNC's.
My goal is to have an IP-TNC that can connect to a host machine via SLIP or
PPP. That is it--no AX.25 to mess with (leave that to the IP-TNC).
I am thinking of using the wg7jkiss.asm code (found in /pub/ham/wg7j/kiss.zip
on ftp.ece.orst.edu) which can be compiled with tasm276, found on
oak.oakland.edu (or any of its mirrors) in /pub/msdos/crossasm/tasm276.zip.
I figure that most people are using DOS, and those who run Linux, as I do, can
use DOSEMU.
Also, on the note of a packet switch, I think that a processor such as a 80x86
would be a poor idea. There are better proccessors out there, and many of them
have FREE assemblers and C compilers. Motorola makes a number of versions of
their 68000 series. David Kelly suggested the MC68306. It has a 68EC000 core
processor (which is a low-power version of the 68000), has a dual UART, and an
onboard DRAM controller that can control up to 64 megabytes of memory. There
are a number of FREE C compilers for this processor, including GNU C. Also,
the Linux operating system has been ported to this series of processors, so
that would provide a nice, pre-emptive multitasking kernel *WITH TCP/IP*!!
If anyone is interested in working on an IP-TNC or an "Awesome Packet Switch",
E-mail me. I would really like to get this going, and hopefully get a good,
working version of an IP-TNC by the time summer is over. I will be away for a
week on vacation, so don't expect to get a reply back real fast.
-----
DJ Gregor, N8QLB
dgregor@bronze.coil.com
"...oh, you use DOS, sorry to hear that..."
------------------------------
Date: Tue, 21 Jun 1994 09:38:45 +0200 (BST)
From: A.Cox@swansea.ac.uk (Alan Cox)
Subject: IP-TNC, the beginings?
To: dgregor@bronze.coil.com (DJ Gregor)
> Also, on the note of a packet switch, I think that a processor such as a 80x86
> would be a poor idea. There are better proccessors out there, and many of them
> have FREE assemblers and C compilers. Motorola makes a number of versions of
> their 68000 series. David Kelly suggested the MC68306. It has a 68EC000 core
> processor (which is a low-power version of the 68000), has a dual UART, and an
> onboard DRAM controller that can control up to 64 megabytes of memory. There
> are a number of FREE C compilers for this processor, including GNU C. Also,
> the Linux operating system has been ported to this series of processors, so
> that would provide a nice, pre-emptive multitasking kernel *WITH TCP/IP*!!
So why not just use a low power PC design. Its cheap and the parts are
easy to get. There is a real danger of getting too carried away here.
Alan
------------------------------
Date: Sun, 19 Jun 1994 22:11:52 -0400
From: goldstein@carafe.tay2.dec.com
Subject: Standard Digital Radio Interface
To: tcp-group@ucsd.edu
I don't have EIA-530 and V.35 in front of me, but I can comment a little
on these and some other options that already exist.
RS-232C is very common, but only spec'd to 19.2 kbps. It is obsolete.
RS-232D and I think EIA-232E (they no longer use "RS") are spec'd for
higher speeds and longer distances, though I don't know the actual
limits. Many devices implmeneted "232C" with longer range, but the
new flavors actually make it supported, by tightening some specs.
It's usable sync too, with a big DB25 connector; that's probably a bit
larger than we want for the digital radio interface. Also, -232C is
bipolar (+-15V) which is a bit tough to generate; I don't know -232E's
voltages but it's also bipolar. My vote: No.
RS-423 is a lot like -232, one-sided bipolar and even interoperable.
RS-422 is differential, so it goes megabits. RS-449 spec's the connector
but it's a big 37-pinner if I recall. Again, not quite right.
V.35 is so popular that the CCITT actually DELETED it from their list
of approved Recommendations! A truly conformant implementation of
V.35-1984 is very difficult. A nonconformant but compatible implementation
is fairly cheap. I think you need ECL or something to be exactly right.
The connector is HUGE and grody. My vote, No. But I don't think it's
necesssarily bad to build something V.35-compatible the way most folks
do, using a smaller connector and cheaper electronics. I've seen many
incompatible ways of wiring V.35 onto say DB25 connectors.
EIA-530 is newer, and while I don't have a copy or know its details, I
am led to believe that it uses the DB25 connector and is electrically
interoperable with most V.35 and RS-422. This may be the best place to
start, though we may want to specify a small-connector subset if that's
adequate.
BTW, I don't see this as a TCP-IP connector. It's for any digital
radio applicatoin, be it TCP/IP, Vanilla AX.25, non-ham, etc. I think
a modem/radio combo would be a nice thing to have, something like what
Tekk does but most of the volume vendors don't, yet. Maybe we could
encourage th em with somethng like this.
There is the issue of "computer-controlled radio" too. Do we want the
SAME connector to do things like change channels? (E.g., Yaesu CAT,
etc.) I'm not convinced either way. V.25bis and X.21 both specify
inband control with an out of band lead to tell whether hte message
is data or control. These are for Sync, the Hayes in-band hack is
not suitable. Again t his could be hard to standardize, since different
radio vendors will want to go their own ways, so at best this can be
only an option.
fred k1io
------------------------------
End of TCP-Group Digest V94 #125
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