HDTenEightyP/NetNews huggingface dataset:
Newsgroups: comp.dcom.lans.ethernet
Subject: Question on 10Base-T
From: vfoao07h@VAX.CSUN.EDU (George Mansoor)
Date: Wed, 8 Apr 1992 19:45:39 GMT
Reply-To: vfoao07h@VAX.CSUN.EDU
Organization: Cal State Northridge

I think that this is a pretty basic question.  I recently setup a friend's 
Novell Network using Twisted-Pair wiring.  Everything worked fine, but I 
noticed one thing.  The wiring (done professionally - not by me) went from 
RJ45 connectors (that were to connect to the hub) to wall plates.  I 
connected all the wires to the 10baseT hub (Synoptics 2800).  I then used 
patch cables (RJ45 connectors on each end) provided by the installer to 
connect the compters NIC to the wall plates.   Everything worked fine.  

What I noticed was that when I pulled the cable from the NIC, but left it in 
the wall plate, the network hung.  When the cable was either put back into the 
NIC, or removed from the wall plate, the network continued to work.  It was 
similar to what happens when you pull a terminator from a thin-net cable.

Can anyone tell me why this happens

Thanks


-----------------------------------
George Mansoor
Cal State Northridge
Business Affairs Systems - BMGT
gmansoor@vax.csun.edu
Xref: sparky comp.dcom.lans.ethernet:562 comp.sys.sun.misc:1809
From: mwr@tridom.uucp (Mark Reardon)
Newsgroups: comp.dcom.lans.ethernet,comp.sys.sun.misc
Subject: Source for ANC-10 (was Connecting two machines without an "Ether")
Date: 8 Apr 92 19:44:02 GMT
Reply-To: mwr@tridom.uucp (Mark Reardon)
Organization: AT&T Tridom; Marietta, Georgia

In article <1992Apr05.165348.26168@donau.et.tudelft.nl>, thomas@duteca2.et.tudelft.nl (Thomas Okken) writes:
|> I want to connect two machines with thick-ethernet ports. Can I save the
|> expense of two transponders (or whatever those little expensive boxes are
|> called), and use some kind of straight-through cable? With some passive
|> components perhaps?
|> I suppose this should be possible, but I don't know anything about the
|> pin-outs and electrical specs of the DB-15 ethernet port. If anyone has done
|> this before, I'd love to hear about it.
|> Thanks!
|> 
|>  - Thomas.
|>
My old company looked for a solution to this problem not to long ago and found something called an "ANC-10".  It looks like an AUI cable with a small ball in the middle (or a snake with a rat as we called it).  The price was approximately $160 +/- 10%.  Each end connect to one standard thick ethernet ports and they could then talk to each other on their private net.  Unfortunately, I can`t remember anything else about it such as who makes it, etc.  If anyone out there knows could they please post the infor



mation?

Thanks,

Mark Reardon (mwr@eng.tridom.com)
From: dave@racer.lkg.dec.com (Dave Lyons)
Newsgroups: comp.dcom.lans.ethernet
Subject: Re: Repeaters
Date: 8 Apr 92 16:14:56 GMT
Article-I.D.: nntpd.35048
Reply-To: dave@racer.lkg.dec.com
Organization: TNSG - MCC Frameworks Technical Support

In article <1992Apr7.223902.27787@ucsu.Colorado.EDU>, barr@tramp.Colorado.EDU
(BARR DOUG) writes:

|> Thanks for the quote, is it from the spec itself? 

Slightly different words, but you can find it in the spec (802.3c-1988)
in section 9.1, paragraph 3, page 95.

|> be 1)coax with no workstations, 2)twisted pair or 3)fiber.

The spec only lists Fiber as a vendor independent IRL. (Inter-
Repeater Link)

The other media would be a vendor specific, non-standard solution.
(but still acceptable, if it met the requirements for delay and such)

Coax, if connected to via a MAU, even if there are only 2 repeaters
is not an IRL, simply a segment that has very few connections.
IRL's, are connected to PORTS (Section 9.2), and not via a MAU.
From: umcarls9@ccu.umanitoba.ca (Charles Carlson)
Newsgroups: comp.dcom.lans.ethernet
Subject: Re: 8-bit vs 16-bit Ethernet Cards
Date: 17 Apr 92 15:01:53 GMT
Organization: University of Manitoba, Winnipeg, Canada

In <92107.131114RMC100@psuvm.psu.edu> Randy Carraghan <RMC100@psuvm.psu.edu> writes:

>What would a ball-park estimate be of the speed gained by using 16-bit cards
>instead of 8-bit in a 10BaseT environment, ISA architecture, 16 node network?

One reason I like 16 bit cards is because you can use the extended interrupts.
In my 386 system, all IRQs from 2-7 are full, so there's no where else to go!

It's something to consider if you plan on stuffing a lot of equipment into
these machines.

Charles

-- 
/ Charles Carlson  umcarls9@ccu.Umanitoba.CA  
\ This .sig now available on a limited edition 2 record set, for 4 easy 
/ installments of $19.95 each. To order, please have your Visa or Mastercard
\ ready and phone: 1-800-555-1212, or send check or MO to 200-155 Carlton St.
From: barr@tramp.Colorado.EDU (BARR DOUG)
Newsgroups: comp.dcom.lans.ethernet
Subject: DEC ethernet equipment names
Date: 7 Apr 92 19:21:15 GMT
Article-I.D.: ucsu.1992Apr7.192115.5898
Organization: U

Some time ago I posted for info regarding DEC ethernet equpment.
The following is what I have compiled (from various sources) though
most of this is from:
RICHARD.DVC@mhs.unc.edu 
--Richard Milward / U.of N.Carolina @ Chapel Hill

  DELNI - DEC Ethernet Local Network Interconnect
          8 Ethernet devices in, 1 Ethernet out (AUI cables)
          an Ethernet concentrator w/optional output

  DELQA - DEC Ethernet Local Q-bus Adapter
          communications controller for Q-bus computers,
                e.g. MicroPDP-11 and MicroVAX
          connects to Ethernet V2.0 or IEEE 802.3 LAN

  DELUA - DEC Ethernet Local Unibus Adapter
          communications controller for Unibus computers,
                e.g. PDP and VAX computers
          connects to Ethernet V2.0 or IEEE 802.3 LAN

  DEMPR - DEC Ethernet MultiPort Repeater (thin-wire)
          8 thin-wire Ethernet inputs, 1 thick-wire Ethernet out
          (a thin-wire Ethernet concentrator w/optional output)

  DEPCA - DEC Ethernet Personal Computer Adapter
          communications controller for IBM-compatible PC/XT/ATs
          (PC/XT bus or AT bus ??)

  DEREP - DEC Ethernet REPeater (also referred to as DEREN)
          inter-connects up to 3 segments of baseband Ethernet cable

  DESPR - DEC Ethernet Single Port Repeater
          connects one thin-wire Ethernet segment to standard Ethernet

  DESTA - DEC Ethernet STation Adapter
          converts standard 15-pin AUI connector to thin-wire cable

  DESVA - DEC Ethernet Synchronous VAX Adapter
          communications controller for MicroVAX 2000 and
                VAXstation 2000 computers
          connects to thin-wire Ethernet network

ALSO:

  DETPA - Thinwire to twisted pair converter/transiever (not really 802.3)

  DETPR - Twisted pair repeater

  DEBET - Ethernet bridge

  DEBAM - Ethernet bridge
  
  DETLB - translan bridge 
Newsgroups: comp.dcom.lans.ethernet
From: whinery@nancy.uhcc.Hawaii.Edu (Alan Whinery)
Subject: Re: Repeaters
Organization: University of Hawaii
Date: Mon, 13 Apr 1992 19:36:07 GMT

In article <5314@npri6.npri.com> richard@npri6.npri.com (Richard Head) writes:
>
>When all nodes on the Ethernet are "daisy-chained" together, isolating
>network problems become much more difficult.  With 10BaseT smarthubs, it
>is very easy to isolate a network problem using SNMP tools because each
>node has its' own network drop.  If you had a very large network, you
>would drop your 10Base2 position in a hurry!!
>-- 
>richard@npri6.npri.com  <Richard Head>
>I've fallen and I can't reach my beer!


Hoo boy, somehow I became the 10Base2 advocate -- 
:>)

I originally was talking about a way to avoid going over repeater limits.

We are not in the habit of installing networks on 10Base2. We have completed 
a the wiring of every building on our campus for 10BaseT, and that is the thrust of 
all new installations currently underway at the University of Hawaii. 

The numerous ethernet portions of our network that have been put together over the
last few years are a conglomeration of thick and thin, and I cannot see any more
building wiring being done on either coax, although the multi-tap nature 
and the longer reach  of thin coax will perpetuate it where many workstations 
must co-exist, or where there is a loner 500 ft away, too close for fiber, 
to far for UTP. 

I have a very large network. We have over 800 hosts on campus, with another
600 to come on this summer -- that 10BaseT wiring is going to make it easy for 
folks to hook up -- as well as regional campuses, which are being connected now as 
well. 

Are smart hubs all that valuable? We have a surprisingly low incidence of link
and host problems, and those that we do get seem to be easy to isolate without
all that SNMP in hubs, although we do speak SNMP to routers here.

What hubs we have that are already in place posess only LED management -- if the
light's green, everything's keen :>).




--
D. Alan Whinery, Computer Networks Engineer |
The University of Hawaii at Manoa           |  networks@uhunix.uhcc.hawaii.edu
2565 The Mall, Honolulu, HI 96822           |  whinery@nancy.uhcc.hawaii.edu
(808)956-6430    FAX (808)956-2412          |  
Newsgroups: comp.dcom.lans.ethernet
From: barr@tramp.Colorado.EDU (BARR DOUG)
Subject: 3Com repeaters with SCSI extention
Organization: U
Date: Thu, 16 Apr 1992 18:02:51 GMT

I am looking for anyone who is using the 3Com LinkBuilder 10BT hubs
(repeaters). We are considering using them, we like the way they
can be daisychained to form a single logical repeater. They use a 
SCSI cable to connect to each other. This would allow our system to
become one more repeater deep.
	Present topology                        Proposed topology

            ---Repeater A---Work A                           |---Repeater A
            |                                    connected   |
connected by --Repeater B....more repeaters         by       |---Repeater B
     short  |               and workstations       SCSI      |
      thin  ---Repeater C---Work B                cables     |---Repeater C 
      wire
Under the Proposed topology Work A transmitting to Work B would only go
through 1 repeater. Under the present topology such transmission would
go through 2 repeaters.
						
Xref: sparky comp.dcom.lans.ethernet:574 comp.dcom.lans.misc:209
From: moshek@FibHaifa.com (Moshe Kochinski)
Newsgroups: comp.dcom.lans.ethernet,comp.dcom.lans.misc
Subject: Information on LAVC wanted..
Date: 9 Apr 92 12:14:11 GMT
Reply-To: moshek@FibHaifa.com
Followup-To: comp.dcom.lans.ethernet
Organization: Fibronics ltd., Haifa - ISRAEL
Originator: moshek@matisse



Hello Neters,

I'm looking for information regarding LAVC protocol.
The information I'm looking for is:

- Use of this protocol over Bridges, (Time-Out trouble-shootings)
- On frame structure
- Performance, and others..

Thanks in advance.

--- Moshe K.



-- 
Moshe Kochinski
------------------------------------------------------------------
Fibronics Ltd., Matam Industrial Park, Haifa 31905, ISRAEL
phones: +972-4-313665/620              Fax: +972-4-517668
From: haynes@cats.ucsc.edu (Jim Haynes)
Newsgroups: comp.dcom.lans.ethernet
Subject: Is there are freely-redistributable rarpd out there?
Date: 16 Apr 92 22:23:57 GMT
Organization: University of California, Santa Cruz


I need to do some messing with a rarpd; and I druther use one that is
freely-redistributable if I can find one.  So far the only one I have
found (at uunet) dates from 1984 and needs some include files for the
pup protocol, so I suspect it's getting a little moldy.
-- 
haynes@cats.ucsc.edu
haynes@cats.bitnet

"Any clod can have the facts, but having opinions is an Art."
        Charles McCabe, San Francisco Chronicle
From: pat@hprnd.rose.hp.com (Pat Thaler)
Date: Fri, 10 Apr 1992 00:18:19 GMT
Subject: Re: Repeaters
Organization: HP Roseville Networks Division
Newsgroups: comp.dcom.lans.ethernet


>    What usually kills a network is high collision rates.  Another case is
>where the delay from one station to another, over the cables, transceivers, and
>thru the repeaters, is longer than the ethernet preamble (8 bytes).  

This is incorrect.  Even on a single segment, the
round trip delay can be longer than 64 bit times (just the media delay for
500 m of coax is 43.3 bit times).  The delay from starting transmit to
detecting collision must be such that the collision is detected before
the end of transmitting a minimum length frame (512 bits from start of
frame delimiter) and the length of the collsion fragment observed anywhere 
on the network must be less than the minimum length frame.  The latter
is the more severe constraint.

>The
>packets collide late (somewhere in the destination address (and I've seen it
>collide in the data field!)), causing many small, fragmented, unintelligible
>packets.  

Since the packets are smaller than a legal frame, they are discarded and
cause no problems.

>If I was forced to install a non-DEC compliant network, I would
>compute the nano-second delay from station to station, including every
>component (AUI, Txcvrs, fiber, etc.), and see if it exceeded the preamble.  

It is non-trivial to calculate from scratch the round trip delay of 
the network.  Some of us in IEEE 802.3 have spent a lot of meeting
hours over the last few years refining and correcting the calculation.
Further time was spent reducing that to a tabular form usable by someone
configuring a network.  The major parts of the calculation are obvious,
but some of the finer points are very subtle.  I doubt any user (or any
person working alone) would end up getting the calculation exactly correct
starting from scratch.

The calculation for interpacket gap shrinkage is simpler, but less widely
understood.

Pat Thaler
Newsgroups: comp.dcom.lans.ethernet
From: harvey@indyvax.iupui.edu
Subject: Re: Duplicate ethernet addresses!
Organization: Indiana University
Date: 14 Apr 92 15:10:46 -0500

In article <1992Apr10.224701.8749@raven.alaska.edu>, riffraff.gi.alaska.edu (craig helmuth) writes:
> A caution to those poor souls troubleshooting ethernets, we have just
> found a 'gotcha' that I hope nobody else has to find...
>
> I was watching our ethernet with a packet capture utility (EtherPeek) and
> over the course of a couple of weeks noticed that one ethernet address
> (the six byte hardware address [that only DEC has the gumption to mess
> with, but thats another story...]) was 'migrating' between different
> IP addresses.
>
> Well, users being what they are, I figured our grad students were
> 'sharing' an X-windows terminal or were swapping out pc interface cards
> for kicks.  Well two days ago I caught two IP addresses using the same
> ethernet address at (more or less) the same time.  I asked our
> UN*X gurus if he knew what was going on...
>
> After a little digging, it seems we have three X-windows terminals from
> Visual Technologies Inc., model Visual-14/ES, that all have identical
> ethernet addresses of 00:00:22:00:13:8f!
>
> Visual is sending new EPROMS...
>
> Has anyone else ever seen this?  After all the time and effort to try
> and keep things unique, I was loath to assume the worst, but no more!
> Or is this a FAQ-of-life, or worse yet, are we totally befuddled?!

My favorite story in this genre appeared on the comp.protocols.tcp-ip.ibmpc
newsgroup a year or two ago.  Something like: Dept. purchases a bunch of
Taiwanese NE1000 clones.  Can't even get _one_ of them to work.  Turns that
besides having the same hardware address, the manufacturer was too cheap to
get a vendor block assigned by the IEEE, and used the company's 3-character
initials in ASCII instead, which turned out to be a multicast block!!!

Oh well.  You get what you pay for.

I'm not trying to cast any aspersions on Visual Technologies Inc.  After all,
they are making good and fixing the problem for you.  Just an observation that
stranger things _have_ happened...

> Craig Helmuth, Network Manager  |  craig@fred.gi.alaska.edu
>          Geophysical Institute  |  fncah@alaska.bitnet
> University of Alaska Fairbanks  |  "Its all FANTASY...until its HISTORY"
>
--
James Harvey
harvey@iupui.edu (preferred) or harvey@indiana.edu
From: KJB6@psuvm.psu.edu
Newsgroups: comp.dcom.lans.ethernet
Subject: Help: Install Ethernet card
Date: 6 Apr 92 12:07:58 GMT
Article-I.D.: psuvm.92097.080758KJB6
Organization: Penn State University

If any one could give me some advice I would really appreciate it. I am trying
to install an ethernet board (3Com Etherlink II ... 3c503) into a Gateway 2000
386/33 using a SpeedStar VGA graphics card. I am have ZERO luck. After
installing the card, and using the machine for about 4-8 minutes, the monitor
begins to produce strange characters across the screen, and then the screen
will either go totally blank, or have vertical black & white stripes on it. In
either case I must reset the machine.  I have the I/O base on the ethernet
card set to 300h and the memory disabled. I am using interrup 5, DMA of 1.
I have talked with both Gateway and 3Com with no luck. Does anyone out there
have a suggestion?

I would really appreciate any information. I would be best if you could e-mail
back to me, because I am not normally in this group.


Ken Bauer   kjb6@psuvm.psu.edu
Pennsylvania State University - Behrend College
From: sarnath@sybil.cs.Buffalo.EDU (Ramnath Sarnath)
Newsgroups: comp.dcom.lans.ethernet
Subject: The concentrator location problem
Date: 8 Apr 92 14:17:08 GMT
Organization: State University of New York at Buffalo/Comp Sci
Originator: sarnath@sybil.cs.Buffalo.EDU


Hi,
	I am looking for references to Heuristics that solve
the "concentrator location problem", known to be NP-hard.

I am interested in knowing how these have performed, what kind of
benchmarks are used for testing, etc.


I am not sure this is the right newsgroup for this query, and if not,
I would be thankful if someone could guide me to the right one...


thanx,

sarnath
(sarnath@sybil.cs.buffalo.edu)
Newsgroups: comp.dcom.lans.ethernet
From: henry@zoo.toronto.edu (Henry Spencer)
Subject: Re: Duplicate ethernet addresses!
Date: Sat, 11 Apr 1992 23:24:27 GMT
Organization: U of Toronto Zoology

In article <1992Apr10.224701.8749@raven.alaska.edu> craig@fred.gi.alaska.edu writes:
>After a little digging, it seems we have three X-windows terminals from
>Visual Technologies Inc., model Visual-14/ES, that all have identical
>ethernet addresses of 00:00:22:00:13:8f!
>...Has anyone else ever seen this?

Incidents like this are not all that uncommon, especially if you count
cases that are caught before customers see them.  Manufacturing people
are really, really oriented to turning out *identical* copies of things.
Having to make each one different is a very difficult concept for them,
not because they can't understand it but because it's so unusual that
they don't *think* about it when they change suppliers or processes.
And, of course, such mistakes are hard to spot when you test things one
at a time...
-- 
GCC 2.0 is to C as SVR4 is to Unix.     | Henry Spencer @ U of Toronto Zoology
                             -Dick Dunn |  henry@zoo.toronto.edu  utzoo!henry
From: byron@yogi.hsc.ucalgary.ca
Newsgroups: comp.dcom.lans.ethernet
Subject: SUMMARY: Decnet/MOP across bridge
Date: 11 Apr 92 09:36:26 MDT

Recently I wrote:
>I have an NCD X terminal on an ethernet segment that I wish to boot via Dec's
>MOP protocol, from a VMS-based VAX on a different ethernet segment.  The two
>segments are connected via a bridge (PCbridge).  Booting via MOP will not work
>across the bridge.  A quick look at a PC ethernet monitor shows no ethernet
>packets from the NCD terminal are getting across the bridge.  All works well
>when I replace the bridge with a repeator (as expected).  My question is:

>Why can't a MOP type packet pass across an ethernet bridge?

I received 4 mail messages.  Most said that bridges should pass MOP from one
segment to the next.  I concluded my copy of PCbridge was hosed and got a new
copy from NorthWestern U.  All works great now!  I've created a file to
summarize the mail I received and can send this file to anyone who requests it.
Special thanks to the following for pointing me in the right direction:

bonnell@coral.cs.jcu.edu.au
brock@cs.unca.edu
RPF@ovro.caltech.edu
stodola@orion.rm.fccc.edu

:byron
________________________________________________________________________
Byron Draudson, Systems Manager               byron@yogi.hsc.ucalgary.ca
Radiology, Foothills Hospital, Calgary, Alberta, Canada   (403) 670-2442
From: henry@zoo.toronto.edu (Henry Spencer)
Newsgroups: comp.dcom.lans.ethernet
Subject: Re: Repeaters
Date: 13 Apr 92 22:18:09 GMT
Organization: U of Toronto Zoology

In article <1992Apr13.184024.17773@news.Hawaii.Edu> whinery@nancy.uhcc.Hawaii.Edu (Alan Whinery) writes:
>... I will point out that twisted pair can't hold up in high-noise
>environments, such as a machine shop or a smelting shop, where large 
>switching transients and RF may be present...

Is this experience, or just your gut feeling?  People who've tested
10BaseT in harsh electromagnetic environments say that it works fine
in all but the severest worst cases.
-- 
GCC 2.0 is to C as SVR4 is to Unix.     | Henry Spencer @ U of Toronto Zoology
                             -Dick Dunn |  henry@zoo.toronto.edu  utzoo!henry
From: pat@hprnd.rose.hp.com (Pat Thaler)
Date: Thu, 9 Apr 1992 23:39:19 GMT
Subject: Re: Repeaters
Organization: HP Roseville Networks Division
Newsgroups: comp.dcom.lans.ethernet

 >Digital Equipment
 >recommends only two (2!!!) repeaters between stations (with devices connected
 >on all three segments).  

That is because DEC's literature (and the DIX Ethernet specification) 
considered the two repeaters connected across a fiber link to be one
repeater.  They called a coax-to-fiber repeater a half-repeater.  The
term half-repeater is a misnomer since such a repeater has all the
functions and delay of a coax-to-coax repeater.  It just has a different
transceiver.  The DEC/Ethernet 2-repeater (4-half-repeater) rule was roughly
equivalent to the IEEE 802.3 4-repeater rule.  Two cases aren't
clear with the 2-repeater rule: what is a fiber-to-fiber repeater and
how do you treat a DTE-to-repeater link segment.  These are clear with
the four repeater rule.

Pat Thaler 

Newsgroups: comp.dcom.lans.ethernet
From: pngai@adobe.com (Phil Ngai)
Subject: Re: Repeaters
Organization: Adobe Systems Incorporated
Date: Tue, 7 Apr 1992 18:29:21 GMT

In article <35011@nntpd.lkg.dec.com> dave@racer.lkg.dec.com writes:
>	Allowable topologies shall contain only one signal path between
>any two points on the network.  A maximum of four Repeater Sets may be in
>the signal path between any two stations on the network.  When four Repeater
>Sets are used in any signal path, the path shall include two link segemnts.

What if there are not two link segments in a path with four repeater sets?

-- 
My opinions are my own.