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Problem with wiring a networking device or devices

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Anonymous
May 15, 2005 2:04:29 AM

Archived from groups: comp.dcom.lans.ethernet (More info?)

Hello from the Eighth Doctor
Does any company that any of you know of make a device to translate Coax/BNC
connector based networking to 10BASE-T?

I have here a DEC Terminal Server model 90L+, it works, I can see it working on
the screen of my host. I need to connect it to my LAN, which is a 10BASE-T based
one. I have the AUIs that contain the same connectors, and have the DB15
connectors at one end, (Your right Rich I have cursed at those things, but never in
your direction.). I also have the same AUIs from Cabletron, and it seems they might
have all been made by AMP since the design matches the one the company has
online. I also have the 10BASE-T to AUI connecter, from Synoptics. One of those
is normally connected to my network for my VS 3100 Model 76.

However I don't have the beast I've described. I also have a hub made to connect
four computers together via the same AUI described method. I'm thinking I can
kludge together something around that hub, since its an active device, but the
problem lies on the connector for the DEC TS, it has attached to one end of T
connector a termination resistor. Someone from Digital Networks suggested that
step.

And that's my problem.
----
Gregg drwho8 atsign att dot net
"This signature disavows itself."
Anonymous
May 15, 2005 2:04:30 AM

Archived from groups: comp.dcom.lans.ethernet (More info?)

The Eighth Doctor wrote:

> Does any company that any of you know of make a device to translate
> Coax/BNC connector based networking to 10BASE-T?

Most of the 10 Mb hubs that were common a few years back had several 10baseT
connectors and one BNC connector. I've got one here. You may still be
able to find one, either new or used.
Anonymous
May 15, 2005 3:12:32 AM

Archived from groups: comp.dcom.lans.ethernet (More info?)

On Sat, 14 May 2005, The Eighth Doctor wrote:

> Hello from the Eighth Doctor
> Does any company that any of you know of make a device to translate Coax/BNC
> connector based networking to 10BASE-T?

We would use one of our old hubs which has 8 (or 12) 10-base-T ports
and an AUI port.

Simply slot a coax transceiver into the AUI port, and away you go.

Not sure if one can still buy such things, but we've got several
festering on the shelf, as must many other folks whose networking goes
back a decade or so.
Related resources
Anonymous
May 15, 2005 3:12:33 AM

Archived from groups: comp.dcom.lans.ethernet (More info?)

In article <Pine.LNX.4.62.0505142309490.3987@ppepc56.ph.gla.ac.uk>,
flavell@ph.gla.ac.uk says...
>
>On Sat, 14 May 2005, The Eighth Doctor wrote:
>
>> Hello from the Eighth Doctor
>> Does any company that any of you know of make a device to translate
Coax/BNC
>> connector based networking to 10BASE-T?
>
>We would use one of our old hubs which has 8 (or 12) 10-base-T ports
>and an AUI port.
>
>Simply slot a coax transceiver into the AUI port, and away you go.
>
>Not sure if one can still buy such things, but we've got several
>festering on the shelf, as must many other folks whose networking goes
>back a decade or so.
Hello from the Eighth Doctor
Nice. Expect that's there, and I'm here. I am based in the US, despite my
"borrowing" of the Doctor's names.

That is the solution I need. Who makes the thing?
---
Gregg drwho8 atsign att dot net
"This signature sleeps."
Anonymous
May 15, 2005 3:12:33 AM

Archived from groups: comp.dcom.lans.ethernet (More info?)

In article <Pine.LNX.4.62.0505142309490.3987@ppepc56.ph.gla.ac.uk>,
Alan J. Flavell <flavell@ph.gla.ac.uk> wrote:
>On Sat, 14 May 2005, The Eighth Doctor wrote:
>
>> Hello from the Eighth Doctor
>> Does any company that any of you know of make a device to translate Coax/BNC
>> connector based networking to 10BASE-T?
>
>We would use one of our old hubs which has 8 (or 12) 10-base-T ports
>and an AUI port.
>
>Simply slot a coax transceiver into the AUI port, and away you go.
>
>Not sure if one can still buy such things, but we've got several
>festering on the shelf, as must many other folks whose networking goes
>back a decade or so.


Allied-Telesys (I may not have the name exactly right) made match-box
sized AUI-UTP and AUI-TW transceivers that cost about $20 the last
time I bought them, may years ago. A few months ago I came across them
in the net womewhere.

Googling just came up with this page that caims that someone still sells
vampire taps. They may have other uninteresting stuff for sale.

http://www.cccmn.com/ProductDetail.jsp?Item=AT-206-05&p...

--
a d y k e s @ p a n i x . c o m

Don't blame me. I voted for Gore.
Anonymous
May 15, 2005 3:30:51 AM

Archived from groups: comp.dcom.lans.ethernet (More info?)

The Eighth Doctor wrote:
>
> Hello from the Eighth Doctor
> Does any company that any of you know of make a device to translate Coax/BNC
> connector based networking to 10BASE-T?
>
> I have here a DEC Terminal Server model 90L+, it works, I can see it working on
> the screen of my host. I need to connect it to my LAN, which is a 10BASE-T based
> one. I have the AUIs that contain the same connectors, and have the DB15
> connectors at one end, (Your right Rich I have cursed at those things, but never in
> your direction.). I also have the same AUIs from Cabletron, and it seems they might
> have all been made by AMP since the design matches the one the company has
> online. I also have the 10BASE-T to AUI connecter, from Synoptics. One of those
> is normally connected to my network for my VS 3100 Model 76.
>
> However I don't have the beast I've described. I also have a hub made to connect
> four computers together via the same AUI described method. I'm thinking I can
> kludge together something around that hub, since its an active device, but the
> problem lies on the connector for the DEC TS, it has attached to one end of T
> connector a termination resistor. Someone from Digital Networks suggested that
> step.
>
> And that's my problem.
> ----
> Gregg drwho8 atsign att dot net
> "This signature disavows itself."

search here for item/code LE1502-R3, see if it is what you want.
http://catalog.blackbox.com/BlackBox/Templates/blackbox...

--reed
Anonymous
May 15, 2005 3:54:11 AM

Archived from groups: comp.dcom.lans.ethernet (More info?)

On Sat, 14 May 2005, The Eighth Doctor wrote:

> >We would use one of our old hubs which has 8 (or 12) 10-base-T ports
> >and an AUI port.
> >
> >Simply slot a coax transceiver into the AUI port, and away you go.
> >
> >Not sure if one can still buy such things, but we've got several
> >festering on the shelf, as must many other folks whose networking goes
> >back a decade or so.
[..]
> That is the solution I need. Who makes the thing?

Well, we've got several, some from 3com and some from AT (Allied
Telesyn), but they're ancient, I doubt that you could buy them now.

Try a google for the terms 10baseT and AUI, it brings several hits
that appear to point to current products that you could buy.

How about this http://www.cir.com/pc/pc.htm#networkhubs

8 Port Mini Network Hub w/ BNC & AUI $69.00

You'd need your coax transceiver too, of course, but maybe you already
have one.
Anonymous
May 15, 2005 3:54:12 AM

Archived from groups: comp.dcom.lans.ethernet (More info?)

In article <Pine.LNX.4.62.0505142348330.3987@ppepc56.ph.gla.ac.uk>,
Alan J. Flavell <flavell@ph.gla.ac.uk> wrote:
>On Sat, 14 May 2005, The Eighth Doctor wrote:
>
>> >We would use one of our old hubs which has 8 (or 12) 10-base-T ports
>> >and an AUI port.
>> >
>> >Simply slot a coax transceiver into the AUI port, and away you go.
>> >
>> >Not sure if one can still buy such things, but we've got several
>> >festering on the shelf, as must many other folks whose networking goes
>> >back a decade or so.
>[..]
>> That is the solution I need. Who makes the thing?
>
>Well, we've got several, some from 3com and some from AT (Allied
>Telesyn), but they're ancient, I doubt that you could buy them now.
>

Here they are. This stuff hasn't changed in 15 years.

http://www.alliedtelesyn.com/products/features.aspx?cid...

Ebay has a bunch of A-T styuff.

--
a d y k e s @ p a n i x . c o m

Don't blame me. I voted for Gore.
Anonymous
May 15, 2005 3:56:44 AM

Archived from groups: comp.dcom.lans.ethernet (More info?)

On Sat, 14 May 2005, Alan J. Flavell wrote:

> How about this http://www.cir.com/pc/pc.htm#networkhubs
>
> 8 Port Mini Network Hub w/ BNC & AUI $69.00
>
> You'd need your coax transceiver too, of course,

I'm dreaming. If your existing kit connects to a BNC then you can
connect to this box's BNC connector (maybe with a T-piece and
terminator).
Anonymous
May 15, 2005 6:59:52 AM

Archived from groups: comp.dcom.lans.ethernet (More info?)

Reed wrote:

> The Eighth Doctor wrote:
>>
>> Hello from the Eighth Doctor
>> Does any company that any of you know of make a device to translate
>> Coax/BNC connector based networking to 10BASE-T?
>>
>> I have here a DEC Terminal Server model 90L+, it works, I can see it
>> working on the screen of my host. I need to connect it to my LAN, which
>> is a 10BASE-T based one. I have the AUIs that contain the same
>> connectors, and have the DB15 connectors at one end, (Your right Rich I
>> have cursed at those things, but never in your direction.). I also have
>> the same AUIs from Cabletron, and it seems they might have all been made
>> by AMP since the design matches the one the company has online. I also
>> have the 10BASE-T to AUI connecter, from Synoptics. One of those is
>> normally connected to my network for my VS 3100 Model 76.
>>
>> However I don't have the beast I've described. I also have a hub made to
>> connect four computers together via the same AUI described method. I'm
>> thinking I can kludge together something around that hub, since its an
>> active device, but the problem lies on the connector for the DEC TS, it
>> has attached to one end of T connector a termination resistor. Someone
>> from Digital Networks suggested that step.
>>
>> And that's my problem.
>> ----
>> Gregg drwho8 atsign att dot net
>> "This signature disavows itself."
>
> search here for item/code LE1502-R3, see if it is what you want.
> http://catalog.blackbox.com/BlackBox/Templates/blackbox...

Froogle "10baset bnc hub" and you'll get around 90 hits, starting at 4
bucks.

> --reed

--
--John
to email, dial "usenet" and validate
(was jclarke at eye bee em dot net)
Anonymous
May 15, 2005 4:51:06 PM

Archived from groups: comp.dcom.lans.ethernet (More info?)

I have Asante hub that has 8 10baseT ports and a 10base2 coax port that I
will give away for the cost of shipping.

Barry Streets


"The Eighth Doctor" <drwho8__NOTME__@att.net> wrote in message
news:W6vhe.213705$cg1.135469@bgtnsc04-news.ops.worldnet.att.net...
> In article <Pine.LNX.4.62.0505142309490.3987@ppepc56.ph.gla.ac.uk>,
> flavell@ph.gla.ac.uk says...
> >
> >On Sat, 14 May 2005, The Eighth Doctor wrote:
> >
> >> Hello from the Eighth Doctor
> >> Does any company that any of you know of make a device to translate
> Coax/BNC
> >> connector based networking to 10BASE-T?
> >
> >We would use one of our old hubs which has 8 (or 12) 10-base-T ports
> >and an AUI port.
> >
> >Simply slot a coax transceiver into the AUI port, and away you go.
> >
> >Not sure if one can still buy such things, but we've got several
> >festering on the shelf, as must many other folks whose networking goes
> >back a decade or so.
> Hello from the Eighth Doctor
> Nice. Expect that's there, and I'm here. I am based in the US, despite my
> "borrowing" of the Doctor's names.
>
> That is the solution I need. Who makes the thing?
> ---
> Gregg drwho8 atsign att dot net
> "This signature sleeps."
>
Anonymous
May 16, 2005 12:36:56 AM

Archived from groups: comp.dcom.lans.ethernet (More info?)

In article <lcydnbZTZ7-WPRrfRVn-pw@comcast.com>, berrys2552@comcast.net
says...
>
>I have Asante hub that has 8 10baseT ports and a 10base2 coax port that I
>will give away for the cost of shipping.
>
>Barry Streets
>
>
>"The Eighth Doctor" <drwho8__NOTME__@att.net> wrote in message
>news:W6vhe.213705$cg1.135469@bgtnsc04-news.ops.worldnet.att.net...
>> In article <Pine.LNX.4.62.0505142309490.3987@ppepc56.ph.gla.ac.uk>,
>> flavell@ph.gla.ac.uk says...
>> >
>> >On Sat, 14 May 2005, The Eighth Doctor wrote:
>> >
>> >> Hello from the Eighth Doctor
>> >> Does any company that any of you know of make a device to translate
>> Coax/BNC
>> >> connector based networking to 10BASE-T?
>> >
>> >We would use one of our old hubs which has 8 (or 12) 10-base-T ports
>> >and an AUI port.
>> >
>> >Simply slot a coax transceiver into the AUI port, and away you go.
>> >
>> >Not sure if one can still buy such things, but we've got several
>> >festering on the shelf, as must many other folks whose networking goes
>> >back a decade or so.
>> Hello from the Eighth Doctor
>> Nice. Expect that's there, and I'm here. I am based in the US, despite my
>> "borrowing" of the Doctor's names.
>>
>> That is the solution I need. Who makes the thing?
>> ---
>> Gregg drwho8 atsign att dot net
>> "This signature sleeps."
>>
>
>
Hello from the Eighth Doctor
I am based in NYC, Queens in fact. What's the shipping costs from where you are
to approximately where I am? If you need my physical address feel free to contact
me off list with details.
------
Gregg drwho8 atsign att dot net
"This signature perspires!"
May 16, 2005 9:02:57 PM

Archived from groups: comp.dcom.lans.ethernet (More info?)

I'll throw a wrench in the works, are you sure it's coax ethernet (thinnet,
10Base5). There was/is a thing called DEC-Net which looks like coax
ethernet....But isn't.


"The Eighth Doctor" <drwho8__NOTME__@att.net> wrote in message
news:NBuhe.213626$cg1.140371@bgtnsc04-news.ops.worldnet.att.net...
> Hello from the Eighth Doctor
> Does any company that any of you know of make a device to translate
Coax/BNC
> connector based networking to 10BASE-T?
>
> I have here a DEC Terminal Server model 90L+, it works, I can see it
working on
> the screen of my host. I need to connect it to my LAN, which is a 10BASE-T
based
> one. I have the AUIs that contain the same connectors, and have the DB15
> connectors at one end, (Your right Rich I have cursed at those things, but
never in
> your direction.). I also have the same AUIs from Cabletron, and it seems
they might
> have all been made by AMP since the design matches the one the company has
> online. I also have the 10BASE-T to AUI connecter, from Synoptics. One of
those
> is normally connected to my network for my VS 3100 Model 76.
>
> However I don't have the beast I've described. I also have a hub made to
connect
> four computers together via the same AUI described method. I'm thinking I
can
> kludge together something around that hub, since its an active device, but
the
> problem lies on the connector for the DEC TS, it has attached to one end
of T
> connector a termination resistor. Someone from Digital Networks suggested
that
> step.
>
> And that's my problem.
> ----
> Gregg drwho8 atsign att dot net
> "This signature disavows itself."
>
Anonymous
May 16, 2005 9:02:58 PM

Archived from groups: comp.dcom.lans.ethernet (More info?)

RC wrote:

> I'll throw a wrench in the works, are you sure it's coax ethernet (thinnet,
> 10Base5). There was/is a thing called DEC-Net which looks like coax
> ethernet....But isn't.

DECnet is a networking protocol, like IP, that can be transported
on ethernet, among other layer 2 protocols.

As DEC was part of the original DIX (the D part) ethernet, it would
seem likely that it was ethernet.

It seems that the 90L+ is LAT, the non-DECnet, non-IP protocol DEC
used for terminal servers.

-- glen
Anonymous
May 17, 2005 2:00:34 AM

Archived from groups: comp.dcom.lans.ethernet (More info?)

RC wrote:

> I'll throw a wrench in the works, are you sure it's coax ethernet
> (thinnet, 10Base5). There was/is a thing called DEC-Net which looks like
> coax ethernet....But isn't.
>

DEC-Net is ethernet. DEC was the "D" in DIX, with Intel and Xerox as the
originators of ethernet.
Anonymous
May 18, 2005 3:41:37 PM

Archived from groups: comp.dcom.lans.ethernet (More info?)

In article <tYmdndrAsI_fzRTfRVn-uw@rogers.com>,
James Knott <james.knott@rogers.com> wrote:
>
>DEC-Net is ethernet. DEC was the "D" in DIX, with Intel and Xerox as the
>originators of ethernet.
>

Lets clarify that a bit.. As I understand it, ethernet was developed at
Xerox PARC, and was in use there, and a few other locations for a few
years before it was marketed as a commercial product. The original ethernet
ran at 3mb/sec, and was designed originally to support the Xerox Alto and
Star.

Dec/Intel/Xerox cooperated to market an improved ethernet as a
commercial product, giving us the 10mb/sec ethernet that we know today.
3Com was also founded around this time by one of the original inventors of
ethernet, following his departure from Xerox PARC.

There's a good book called "Dealers of Lightning" that details a lot of
what went on at Xerox PARC during the early years when ethernet was invented,
along with the Alto, the laser printer, and the graphical user interface.



--
-- Welcome My Son, Welcome To The Machine --
Bob Vaughan | techie @ tantivy.net |
| P.O. Box 19792, Stanford, Ca 94309 |
-- I am Me, I am only Me, And no one else is Me, What could be simpler? --
Anonymous
May 18, 2005 6:02:47 PM

Archived from groups: comp.dcom.lans.ethernet (More info?)

Hi,
as someone who grew up with these protocols :-) here're my 2c


glen herrmannsfeldt schrieb:
> RC wrote:
>
>> I'll throw a wrench in the works, are you sure it's coax ethernet
>> (thinnet,
>> 10Base5). There was/is a thing called DEC-Net which looks like coax
>> ethernet....But isn't.
>
>
> DECnet is a networking protocol, like IP, that can be transported
> on ethernet, among other layer 2 protocols.

Yes, DECNET Phase IV is a L3-protocol, just like IPX, IP or Appletalk.
It is a routable protocol and the predecessor of DECNET phase V, which
is the first and only true ISO/OSI-implementation (AFAIK)
>
> As DEC was part of the original DIX (the D part) ethernet, it would
> seem likely that it was ethernet.
>
Well, this protocol DOES run on ethernet and fddi, but is, in theory,
not limited to that. DECNET uses the feature of "locally administered
MAC-addresses", usually in the range AA:.. So, every L2-system capable of
a) hardware-addressing and
b) broadcasting
could run decnet.

> It seems that the 90L+ is LAT, the non-DECnet, non-IP protocol DEC
> used for terminal servers.
LAT is just another L3 protcol, but this time not routable (just as
NETBEUI). It is used for terminalservices only and relies on a broadcast
mechanism for announcing the "services. I've not seen any other
implementation. Again, LAT relies on the same L2-protocols as decnet
since they are related.

Mathias
--
CCIE #11220
Everything written is MY opinion only, not the one of my company or
employer unless otherwise noted

The early bird gets the worm, but the second mouse gets the cheese

My signature is certified by Fraunhofer Society.
The root-ca IS trusted but the browser-manufacturers want big $ to have
it included
Anonymous
May 18, 2005 6:02:48 PM

Archived from groups: comp.dcom.lans.ethernet (More info?)

In article <d6fat7$81r$1@lnx107.hrz.tu-darmstadt.de>,
Mathias Gaertner <Mathias.Gaertner@igd.fraunhofer.de> wrote:

> Hi,
> as someone who grew up with these protocols :-) here're my 2c
>
> glen herrmannsfeldt schrieb:
> >
> > DECnet is a networking protocol, like IP, that can be transported
> > on ethernet, among other layer 2 protocols.
>
> Yes, DECNET Phase IV is a L3-protocol, just like IPX, IP or Appletalk.
> It is a routable protocol and the predecessor of DECNET phase V, which
> is the first and only true ISO/OSI-implementation (AFAIK)

Actually, DECnet is a complete architectural suite, including protocols
from Layer 1 up to Layer 8. Yes, that's right, I said Layer *EIGHT*. The
DECnet Phase IV stack model included the following:

Layer 1--Physical Link Layer: Essentially the same as the OSI Physical
Layer

Layer 2--Data Link Layer: Essentially the same as the OSI Data Link
Layer. Supported technologies included Ethernet, X.25, and DDCMP, DEC's
proprietary Digital Data Communications Message Protocol.

Layer 3--Routing Layer: Essentially the same functionality as the OSI
Network Layer. However, I consider the term "Routing Layer" to be more
properly descriptive of the primary function performed, i.e., routing
packets across the internetwork.

We *consciously* chose NOT to call this layer the "Network" layer for
historical reasons. In DECnet Phase III, Layer 3 was called the
*Transport* Layer (although it performed internetwork routing, the same
as any Layer 3 protocol), and Layer 4 was called the *Network* Layer,
although it did the end-to-end communications functions of a typical
Layer 4. That is, DECnet Phase III reversed the terminology of Layers 3
and 4 relative to OSI. This was not an "error"; DECnet Phase III
predated the OSI model, so we were not bound by any widespread
understanding of the meaning of given terms.

Trust me, this caused no end of confusion during the late '70s and early
'80s, as us "old timers" at DEC used "Network" to mean end-to-end, and
"Transport" to mean internetwork routing. So that we didn't have to
totally flip the terms and stand on our heads, in Phase IV we went to
"neutral" terms for these two layers, avoiding either "Network" or
"Transport" for either of them. When Phase V came around, DEC had fully
migrated to the OSI model, and used the now-standard terms.

Layer 4--End Communication Layer: As I said above, this is the same
functionality as the OSI transport, but with a "neutral" name (relative
to DECnet Phase III). Actually, as with "Routing Layer" for Layer 3, I
think "End Communication" is more descriptive of the functions
performed, but the terms never caught on outside of DEC.

Layer 5--Session Control Layer: Essentially the same as the OSI Session
Layer.

Layer 6--Network Application Layer: Essentially the same as the OSI
Application Layer. The most common modules included file transfer and
access (a la FTP), and remote virtual terminal (a la Telnet).

Layer 7--Network Management Layer: This does not exist in the OSI model
as a "layer" in the stack. In OSI, network management is "on the side",
i.e., it has insight into every layer through a private network
management interface. In DECnet, network management was viewed as a
functional layer in the stack.

Also note that DECnet did not have any Presentation Layer. To the extent
that there are no incompatibilities among data-storage formats among
machines, there is no need for this function. Since all of the machines
in a DECnet were DEC machines, running DEC software (at least in the
beginning), there was little need for canonical data formatting. To the
extent that DECnet users needed to access files on non-DEC machines
(e.g., through the DECnet-SNA gateway), the format conversion was done
in the gateway application, at the Network Application Layer (Layer 6 in
DECnet).

Layer 8--User Layer: DECnet models user applications communicating
across the network as residing within a network layer. OSI considers
these to be "outside" the network. This is more of a semantic issue than
anything else, although it is clearer in DECnet that user programs do
NOT reside in the "Application Layer."

I know many people who (wrongly) think that the OSI Application Layer
contains end-user applications. Architecturally, it does not; entities
within the OSI Application Layer are application *interface* routines,
e.g. X.400 e-mail messaging. Placing end-user applications in a separate
layer makes this abundantly clear.

> LAT is just another L3 protcol, but this time not routable (just as
> NETBEUI).

Actually, LAT is a terminal service application (OSI Layer 7) protocol
that runs directly over Ethernet. It is *NOT PART OF DECnet*; it and
uses NO DECnet functionality, other than possibly sharing an Ethernet
controller with the DECnet stack. The fact that LAT does not include any
internetwork capability is what makes it "unroutable".

Note that there is *nothing wrong* (architecturally) with having an
application interface directly with Layer 2; there is no requirement to
use all of the functionality in a given stack. This is a tradeoff; by
omitting functionality one loses certain capabilities (e.g., the ability
to communicate across an internetwork). In return, you might get better
performance in the target environment.

In reality, LAT was never intended to be what it came out to be. In the
early '80s, we were working on a number of new products and ideas. One
of them was a low-cost terminal server that could be implemented with
relatively little processing power and memory; DECnet required a lot of
both. As an *experiment*, one of the software guys cobbled together a
miniature terminal access program in his basement over the weekend
(literally), so that we could play with the equipment and see how things
worked. In order to get it up quickly (no pun intended), he wrote the
code to operate directly over the Ethernet controller interface, and
avoided the entire DECnet protocol stack.

Unfortunately (as discussed below), the performance was vastly better
than the DECnet VTP (Virtual Terminal Program, a.k.a. the "Set Host"
command on VMS). IIRC, we were able to support 64 simultaneous terminal
sessions on a terminal server using a single 6 MHz 68000 (what became
the DECserver 100). At the host (VAX) end, terminal performance was
better going through LAT than it was going through a DZ-11.

For you under-50 or non-DEC types, a DZ-11 was the standard RS-232
terminal interface, used for direct connection of terminals to a VAX
mainframe, similar to the serial port on a modern machine. That is, we
were getting better terminal response by going through the *network*
than if we were directly connected to the mainframe! This was primarily
because the DZ-11 (like most serial ports) generated a host interrupt
for each character typed; LAT generated a host interrupt for each packet
received, which could contain many keystrokes from many different,
simultaneous terminal sessions. LAT gathers up all keystrokes from all
ports on the terminal server over a period of 20 ms or so, and sends
them off in a single packet to the target host.

The product marketing folks got so worked up about this "screaming"
terminal server that they made us convert this "cobbled basement
prototype" into a commercial product; the end result was LAT--a very
fast terminal server protocol that was limited to a single Layer 2
entity. In part, it was the success of LAT that pushed DEC to develop
and push bridging technology, since a bridge allowed multiple physical
Ethernet to act as a single logical LAN, extended the reach of LAT
terminal services.

Sorry for the long post, but: (1) I thought it might be enlightening,
(2) I have lots of time now that school is out, and (3) It was fun (for
me) to recollect some of this stuff. The one thing I'm trying to
remember (but can't, for the moment) is the name of the guy who wrote
the LAT code over the weekend. It will come to me.


--
Rich Seifert Networks and Communications Consulting
21885 Bear Creek Way
(408) 395-5700 Los Gatos, CA 95033
(408) 228-0803 FAX

Send replies to: usenet at richseifert dot com
Anonymous
May 18, 2005 8:05:02 PM

Archived from groups: comp.dcom.lans.ethernet (More info?)

Rich Seifert wrote:

> For you under-50 or non-DEC types, a DZ-11 was the standard RS-232
> terminal interface, used for direct connection of terminals to a VAX
> mainframe, similar to the serial port on a modern machine.

Yep, I remember them, along with (IIRC) the DV-11 and also the Data General
ALM - 8 & ALM-16. Incidentally, I used to work on a Collins system, which
had a lan that predates ethernet by several years. It used a TDM loop,
instead of packets. This system was used to front end a Univac system, for
Air Canada and it also used several PDP 11 systems, containing a few cards
built with a Motorola 6800 and 8 UARTs, to handle the world wide agent's
terminal traffic for Air Canada.
Anonymous
May 18, 2005 8:07:24 PM

Archived from groups: comp.dcom.lans.ethernet (More info?)

Bob Vaughan wrote:

> The original ethernet ran at 3mb/sec

I believe it was 2.94 Mb. Incidentally, 3 millibit/sec would be a tad
slow. ;-)
Anonymous
May 19, 2005 2:05:16 AM

Archived from groups: comp.dcom.lans.ethernet (More info?)

Rich Seifert <usenet@richseifert.com.invalid> writes:

> Sorry for the long post, but: (1) I thought it might be enlightening,
> (2) I have lots of time now that school is out, and (3) It was fun (for
> me) to recollect some of this stuff.

Never mind. I'd love to read more of this historical stuff.

Jens
Anonymous
May 19, 2005 7:12:23 AM

Archived from groups: comp.dcom.lans.ethernet (More info?)

In article <RY6dnfqQ25bjPRbfRVn-uQ@rogers.com>,
James Knott <james.knott@rogers.com> wrote:
>Bob Vaughan wrote:
>
>> The original ethernet ran at 3mb/sec
>
>I believe it was 2.94 Mb. Incidentally, 3 millibit/sec would be a tad
>slow. ;-)

I stand corrected.. :-)


--
-- Welcome My Son, Welcome To The Machine --
Bob Vaughan | techie @ tantivy.net |
| P.O. Box 19792, Stanford, Ca 94309 |
-- I am Me, I am only Me, And no one else is Me, What could be simpler? --
Anonymous
May 19, 2005 3:35:19 PM

Archived from groups: comp.dcom.lans.ethernet (More info?)

Rich Seifert wrote:

(snip)

> Actually, DECnet is a complete architectural suite, including protocols
> from Layer 1 up to Layer 8. Yes, that's right, I said Layer *EIGHT*. The
> DECnet Phase IV stack model included the following:

Somewhere I heard a story that the OSI seven layers were a compromise
between six and eight proposed by two sides. Is this the eight?

(I heard that about the same time as the story of ATM's 48 bytes being
a compromise between 32 and 64.) (Though I would have said it should be
the geometric mean instead.)

(snip)

>>LAT is just another L3 protcol, but this time not routable (just as
>>NETBEUI).

> Actually, LAT is a terminal service application (OSI Layer 7) protocol
> that runs directly over Ethernet. It is *NOT PART OF DECnet*; it and
> uses NO DECnet functionality, other than possibly sharing an Ethernet
> controller with the DECnet stack. The fact that LAT does not include any
> internetwork capability is what makes it "unroutable".

Well, maybe part of DECnet in the sense that it isn't TCP/IP, and
a networked VAX without TCP/IP won't talk to a TCP/IP terminal server.

As I remember, (along with a discussion in another group) DECnet was
very expensive. If LAT was licensed separately, that would make it
useful even for non-networked machines.

(snip)


(snip)

> For you under-50 or non-DEC types, a DZ-11 was the standard RS-232
> terminal interface, used for direct connection of terminals to a VAX
> mainframe, similar to the serial port on a modern machine. That is, we
> were getting better terminal response by going through the *network*
> than if we were directly connected to the mainframe! This was primarily
> because the DZ-11 (like most serial ports) generated a host interrupt
> for each character typed; LAT generated a host interrupt for each packet
> received, which could contain many keystrokes from many different,
> simultaneous terminal sessions. LAT gathers up all keystrokes from all
> ports on the terminal server over a period of 20 ms or so, and sends
> them off in a single packet to the target host.

I think I remember this when the 8xxx series VAX came out. They didn't
have serial ports, but had to be connected through such terminal
servers. The place I was at then had Gandalf for connecting terminals
to different machines, so it was then two levels to get to the machine.
It was explained that this was faster than serial ports on the machine,
which seemed strange. Well, much DEC software expects character by
character response (consider TECO, or even EDT).

Otherwise, IBM mainframe systems generally interrupt once per line,
for normal terminals, or even once per page for 3270's. You can't
write editors that depend on character I/O.

-- glen
Anonymous
May 19, 2005 7:53:33 PM

Archived from groups: comp.dcom.lans.ethernet (More info?)

glen herrmannsfeldt wrote:

> (I heard that about the same time as the story of ATM's 48 bytes being
> a compromise between 32 and 64.)  (Though I would have said it should be
> the geometric mean instead.)

45.254834 bytes??? ;-)
Anonymous
May 19, 2005 7:53:34 PM

Archived from groups: comp.dcom.lans.ethernet (More info?)

James Knott wrote:
> glen herrmannsfeldt wrote:

>>(I heard that about the same time as the story of ATM's 48 bytes being
>>a compromise between 32 and 64.) (Though I would have said it should be
>>the geometric mean instead.)

> 45.254834 bytes??? ;-)


Well, I would round to 45.

Some years ago I was on jury duty for a civil case. Using a very
complicated system the jury came up with an amount for damages.

After the case one of the lawyers told us the last settlement amounts
that the two sides had come up with. The jury amount was pretty close
to the geometric mean of the two.

Say, for example, the numbers were 10000 and 100 bytes. Which makes a
more fair compromise, 1000 or 5050? 5050 is about half the first value
and over 50 times the second, not so fair if you ask me.

(Remember, Moore's law is exponential.)

-- glen
Anonymous
May 20, 2005 7:28:30 AM

Archived from groups: comp.dcom.lans.ethernet (More info?)

In article <1116277453.c3241e3f3ab30b37c5e6bb7d2f9bcd47@teranews>,
no-spam@not-real.com says...
>
>I'll throw a wrench in the works, are you sure it's coax ethernet (thinnet,
>10Base5). There was/is a thing called DEC-Net which looks like coax
>ethernet....But isn't.
>
>
>"The Eighth Doctor" <drwho8__NOTME__@att.net> wrote in message
>news:NBuhe.213626$cg1.140371@bgtnsc04-news.ops.worldnet.att.net...
>> Hello from the Eighth Doctor
>> Does any company that any of you know of make a device to translate
>Coax/BNC
>> connector based networking to 10BASE-T?
>>
>> I have here a DEC Terminal Server model 90L+, it works, I can see it
>working on
>> the screen of my host. I need to connect it to my LAN, which is a 10BASE-T
>based
>> one. I have the AUIs that contain the same connectors, and have the DB15
>> connectors at one end, (Your right Rich I have cursed at those things, but
>never in
>> your direction.). I also have the same AUIs from Cabletron, and it seems
>they might
>> have all been made by AMP since the design matches the one the company has
>> online. I also have the 10BASE-T to AUI connecter, from Synoptics. One of
>those
>> is normally connected to my network for my VS 3100 Model 76.
>>
>> However I don't have the beast I've described. I also have a hub made to
>connect
>> four computers together via the same AUI described method. I'm thinking I
>can
>> kludge together something around that hub, since its an active device, but
>the
>> problem lies on the connector for the DEC TS, it has attached to one end
>of T
>> connector a termination resistor. Someone from Digital Networks suggested
>that
>> step.
>>
>> And that's my problem.
>> ----
>> Gregg drwho8 atsign att dot net
>> "This signature disavows itself."
>>
>
>
Hello from the Eighth Doctor
Quite. It is indeed DECNet. However their hardware does do normal Ethernet.
However, I participate in a forum who discusses the implementation of the LAT
protocol over Linux, called appropriately enough Linux-DECnet,
http://linux-decnet.sf.net
---
Gregg drwho8 atsign att dot net
Anonymous
May 20, 2005 1:07:39 PM

Archived from groups: comp.dcom.lans.ethernet (More info?)

In article <3rudnbH3zb3UQRHfRVn-hg@comcast.com>,
glen herrmannsfeldt <gah@ugcs.caltech.edu> wrote:

> Rich Seifert wrote:
>
>
> > Actually, LAT is a terminal service application (OSI Layer 7) protocol
> > that runs directly over Ethernet. It is *NOT PART OF DECnet*; it and
> > uses NO DECnet functionality, other than possibly sharing an Ethernet
> > controller with the DECnet stack. The fact that LAT does not include any
> > internetwork capability is what makes it "unroutable".
>
> Well, maybe part of DECnet in the sense that it isn't TCP/IP, and
> a networked VAX without TCP/IP won't talk to a TCP/IP terminal server.
>

No, LAT is "not DECnet" in the sense that it has nothing to do with the
DECnet protocol stack. It does not use any of the DECnet protocols, from
Layer 3 on up. The LAT entity interfaced directly with the Ethernet
controller/device driver (downward), and with the operating system
terminal driver (upward).

While it is true that "a networked VAX without TCP/IP won't talk to a
TCP/IP terminal server," this is irrelevant. A networked VAX without LAT
won't talk to a LAT terminal server, either. They are completely
independent. By the way, during the 1980s, LAT was a much more popular
terminal server protocol than anything running on TCP/IP. (In addition,
DECnet was more popular than TCP/IP, until the very late 1980s.)

Also (unlike DECnet) LAT did not require that the Ethernet MAC address
be reconfigured to conform to the DECnet Routing Layer conventions.

> As I remember, (along with a discussion in another group) DECnet was
> very expensive. If LAT was licensed separately, that would make it
> useful even for non-networked machines.
>

I don't see how LAT could be useful on a non-networked machine; LAT
operates only over an Ethernet network. At one point, LAT was the *only*
DEC-supported means to connect terminals to VAXen; by the late 1980s
they had dropped support for any directly-connected terminals. LAT was
bundled with the core operating system, and did not require any separate
license.

(DECnet was also bundled with the core O/S, however you have to purchase
a cryptographic "key" to unlock the functionality. You are correct that,
depending on the system configuration, this "key" could be expensive.)


>
> Otherwise, IBM mainframe systems generally interrupt once per line,
> for normal terminals, or even once per page for 3270's. You can't
> write editors that depend on character I/O.
>

Well, clearly you can, as most editors do rely on keystroke-by-keystroke
interpretation. Take vi for instance; the fact that it interprets each
keystroke in the context of each prior keystroke (e.g., an ESC shifts
you out of input-mode for the next character) is a primary reason why
Telnet sends one character-per-packet, and the visual "echo" of the
keystroke on the screen must come from the remote host.


--
Rich Seifert Networks and Communications Consulting
21885 Bear Creek Way
(408) 395-5700 Los Gatos, CA 95033
(408) 228-0803 FAX

Send replies to: usenet at richseifert dot com
Anonymous
May 21, 2005 1:52:28 AM

Archived from groups: comp.dcom.lans.ethernet (More info?)

Rich Seifert wrote:

(snip)

>>As I remember, (along with a discussion in another group) DECnet was
>>very expensive. If LAT was licensed separately, that would make it
>>useful even for non-networked machines.

> I don't see how LAT could be useful on a non-networked machine; LAT
> operates only over an Ethernet network. At one point, LAT was the *only*
> DEC-supported means to connect terminals to VAXen; by the late 1980s
> they had dropped support for any directly-connected terminals. LAT was
> bundled with the core operating system, and did not require any separate
> license.

Not networked, as in not connected to any other hosts, machines that
actually do useful computing work.

> (DECnet was also bundled with the core O/S, however you have to purchase
> a cryptographic "key" to unlock the functionality. You are correct that,
> depending on the system configuration, this "key" could be expensive.)

>>Otherwise, IBM mainframe systems generally interrupt once per line,
>>for normal terminals, or even once per page for 3270's. You can't
>>write editors that depend on character I/O.

> Well, clearly you can, as most editors do rely on keystroke-by-keystroke
> interpretation. Take vi for instance; the fact that it interprets each
> keystroke in the context of each prior keystroke (e.g., an ESC shifts
> you out of input-mode for the next character) is a primary reason why
> Telnet sends one character-per-packet, and the visual "echo" of the
> keystroke on the screen must come from the remote host.

With hardware that only interrupts the host on carriage return you
can't write vi or teco.

3270 based editors have the user modify the screen and then send the
changes to the host as one I/O operation. I believe telnet has
a line mode to allow it to work with such hosts.

-- glen
Anonymous
May 31, 2005 4:18:42 PM

Archived from groups: comp.dcom.lans.ethernet (More info?)

In article news:usenet-1C7DED.09185718052005@news.isp.giganews.com,
Rich Seifert wrote:
> In article <d6fat7$81r$1@lnx107.hrz.tu-darmstadt.de>,
> Mathias Gaertner <Mathias.Gaertner@igd.fraunhofer.de> wrote:
> Actually, DECnet is a complete architectural suite, including
> protocols from Layer 1 up to Layer 8. Yes, that's right, I said Layer
> *EIGHT*. The DECnet Phase IV stack model included the following:
>
Great to hear the history of such things.
--
Alan J. McFarlane
http://www.alanjmcf.me.uk/
Please follow-up in the newsgroup for the benefit of all.
!