🚀 go-pugleaf

> Both the Bridge TCP boxes and the DEC LAT boxes can be used as
> either true terminal servers or "milking machines".  That is, you
> can have the following:

Good point:  I forgot to mention that.  The picture should straighten
out the distinction (which seems to be confusing many people) between
{EtherTIP|EtherTAC} and {milking machine|Ethernet port selector}.
Milking machines may be quite useful, but all the machines we're interested
in providing terminal access to already have Ethernet connections.

I've gotten a couple more responses.  It appears DEC makes a DECNET
based thing.  Several more raves about Bridge (including one from
the vendor), of which I quote part of one (not the one from the vendor).
Something from U. Alberta, on which I leave the identifying marks,
as it wouldn't make sense otherwise.

As before, there are no guarantees on any information in this article.

I will wait another week, and if I have received anything else worth posting
by then, I will post another summary.

----------------------------------------------------------------------

DEC has a thing called a DECSA which multiplexes 32 terminals onto an
Ethernet for $20,000.  I gather that internally it's a PDP-11, and it
speaks everybody's favorite protocol, DECnet.  Call 603-884-7993 for info.

------------------------------

John - as far as I know, if you want TCP/IP (as we do), the only
game in town is from Bridge Communications (they're in Silicon
Valley somewhere.)  They have two products: the CS/1, which costs
$10K for an 8 port model and can expand to 32 ports at $2K per
8 ports; and the CS/100, which costs $4K for 4 ports, $5K for 10,
and $6K for 14.  If you work out the math, the CS/100 always costs
less, but the CS/1 is more expandable (it has a multibus) so new
products come out for the 1 first.

Bridge is an XNS company, but they do support TCP/IP, and it's a
pretty good product.  We have one of each and are basically happy;
we are buying a pile of CS/100's.

If you are willing to take XNS, you can look at Bridge's XNS software
for the CS/1 or 100, or Interlan's similar products.

AMD was going to do an Ethertip (we call them a TAC, since that
seems to be the preferred ARPA term these days - Terminal Access
Controller) but they dropped the project.

I understand DEC has one too, but it only supports DECNET.

The CS/* support both user and server telnet.  You can plug in a
dumb hosts on RS232 ports and the CS/1 will accept telnet connections
for it and get you one of the RS232 ports.  They jump through hoops;
you can have multiple connections open from a port and switch between
them dymanically, you can set flow control and the like dynamically,
program in macros which can be invoked with a simple command or on power
up, display network stats, etc.  There are two levels of super user.

Here are the minuses.  Most are minor.

(1) It won't talk to a 3B2 3Bnet board.  We suspect a hardware incompatibility,
since the 3Bnet won't talk to an Interlan board either.  This is major to
us but probably not to you.  It talks fine to an Interlan, DEUNA, Excelan,
and 3Com.

(2) It's fussy about dynamic configuration of baud rate and parity.  To
get it to recognize baud rate you have to type .CR. which is worse than
many that you only have to type CR .  The parity for a port has to be
set and it really cares - this makes dialups difficult (you have to pick
a standard parity and require everyone dialing in to use it.)

(3) We've had a couple of hung connections, one beat on the CPU of our VAX.
They don't reproduce often enough to track down (2 in 6 months.)

(4) The non-Bridge transceiver cable we connect it to doesn't fit well
(this is a general Ethernet gripe) and sometimes I have to wiggle the
cable when it goes off the net.

(5) It doesn't like HP 2621's for some reason I can't recall - you have
to cut one of the RS232 leads to make it talk to a 2621.

------------------------------

Date: Mon, 22 Jul 85 09:53:42 mdt
>From: ihnp4!alberta!myriasb!ref (Dick Foster)
Subject: Re: Ethertips
In-Reply-To: USENET article <2394@ut-sally.UUCP>

The University of Alberta Computing Science Department has Ethertips that
were put together in house. An individual Ethertip consists of a
SUN 100 workstation (without a monitor or keyboard) with an Ethernet
board and 2 octal serial interface boards (providing 16 terminal lines).

The "system" software is a port of the BSD4.2 networking software along with
a minimal amount of machine dependent support code (about 800 lines
for the ethernet interface routine, 350 lines for the octal serial
interface, and 300 lines for miscellaneous support routines). It would
be a simple task to port this code to a different hardware configuration.

The interface to the "user" level code is of course the same as in
BSD4.2, so writing the upper level protocol code is easy.
Telnet is supported, and a similar protocol which allows the Ethertip
to echo locally when possible to reduce network traffic. The ability
to "stack" login sessions on several machines is included.

If you would like more information or are interested in obtaining a copy of
the source code, contact me or Steve Sutphen (..ihnp4!alberta!steve) .
(I am no longer working at the University, but I developed the code for the
Ethertips and am willing to help with any problems). 

				Dick Foster
				..ihnp4!alberta!myrias!ref

------------------------------
-- 

John Quarterman, jsq@ut-sally.ARPA, {ihnp4,seismo,ctvax}!ut-sally!jsq