HDTenEightyP/NetNews huggingface dataset:
From: seifert@netcom.com (Rich Seifert)
Newsgroups: comp.dcom.lans.ethernet
Subject: Re: reusable coax-cable-connectors
Date: 16 Oct 92 21:09:39 GMT
Organization: Netcom - Online Communication Services  (408 241-9760 guest)

In article <1be08fINN7dl@fbi-news.Informatik.Uni-Dortmund.DE>, voelker@ls12w (Matthias Voelker) writes:
> Hello all in this group!
> 
> My problem is that I want to figure out the best place for
> a workstation in an ethernet.
> 
> So is there a connector that connects to an ethernet without
> cutting the traffic and without leaving traces??? Maybe the
> "vampire"-type piercing technique does the job?? 
>
The easiest thing to do (assuming that you have a ThickWire network)
is to attach a transcevier with a long drop cable, and then
move the device anywhere you want (within the 50 meter radius of
the drop cable).

There is no performance difference or advantage relative to the physical
location of a device on an Ethernet. It is simply a matter of
where you want to put the unit in your workplace.
 
> My other question goes more into detail concerning the possibility
> of processing data read from a THICK ethernet with the card-input
> for THIN ethernet. As far as I know, the specifications for thin and
> thick ethernet are basically the same, aren't they? Why can't I pick
> signals from a thick ethernet and receive them with the usual thin
> ethernet input of an ethernet card? Dealers all told me it wouldn't
> work but no one could explain. Maybe you can?
> 

If you actually cut the thickwire coax, and installed a T connector
with an adapter to a BNC connector, it WOULD work exactly as you
described. I don't recommend this, however.

You would have to bring the thick coax down to the workstation
(no stubs allowed), and the network would be down while you installed
this kluge. I don't know of anyone making a vampire tap that terminates
in a BNC connector, as it is not a common or convenient means of
attaching workstations.

-- 
Rich Seifert                    Networks and Communications Consulting
seifert@netcom.com              (408) 996-0922
                                (408) 996-2860 FAX
"... specialists in Local Area Networks and Data Communications systems"
From: sysrick@orion.spd.louisville.edu (Rick McTeague)
Newsgroups: comp.dcom.lans.ethernet
Subject: Need: recommendations for high-bandwidth hubs
Date: 7 Oct 92 15:05:01 GMT
Article-I.D.: starbase.sysrick.718470301
Organization: University of Louisville

I'm looking for recommendations for high-bandwidth hubs, which take in
multiple ethernet networks and bridge between them.

I've talked to a couple of manufacturers who are sending me some literature,
and I'd like to get some opinions from anyone who's actually used one.

The people I've talked to are Artel (who are in the lead because their
"Turbo" box is the least expensive at $7000-$10000), Hughes Lan, and 
Ungermann-Bass (sp?). Any other vendors I should talk to?

Also, if you know of a buyer's guide I might dig up somewhere, I'd like to
know about it.

Thanks in advance,
Rick
-- 

Rick McTeague
Electrical Engineering Department, Speed Scientific School
University of Louisville, Louisville, KY 40292
(502) 588-7020

Internet: sysrick@starbase.spd.louisville.edu

Disclaimer: I'm a stand-up comedian; if anyone takes me seriously, I'm
            doing something wrong!
Newsgroups: comp.dcom.lans.ethernet
From: rpw3@rigden.wpd.sgi.com (Rob Warnock)
Subject: Re: ? Relating collision, utilization rates
Organization: Silicon Graphics, Inc.  Mountain View, CA
Date: Wed, 7 Oct 1992 08:57:16 GMT

Leonard@Arizona.EDU writes:
+---------------
| I read Bob Metcalfe once say this: the one thing he would do differently
| if he were to invent Ethernet again, would be to call a "collision"
| something else, because it weirds out people who wear suits...
+---------------

And gives advocates of competing LAN technologies such a lovely emotion-
laden issue to attack with! Many people have heard of "Ethernet collisions";
far fewer understand that a "collision" does *not* imply loss of data or
even transport-level retransmission.

Yeah, Metcalfe should have called it "media access negotiation", or maybe
even "attempting to capture the medium".  And the "collision detect" line
from the transceiver could be "Multiple_Senders". Hmmm... That would make
the description of Ethernet sound like this:

    "When a station has something to transmit, first it listens to see
    if the medium is busy, deferring to transmissions already in progress.
    Then, when it detects quiet, it attempts to 'capture' the medium by
    beginning to transmit. If during the first 'slot time' of its transmission
    it detects (from the transceiver's 'Multiple_Senders' signal) that one
    or more other stations are also attempting to capture the medium, first
    it ensures that all stations will agree that the capture attempt was
    unsuccessful by continuing to transmit for a short time (the so-called
    'jam'), then ceasing to transmit. It then retries its transmission after a
    random number of slot-times drawn from [0..2**n], where "n" is the number
    of capture attempts that have been made so far on the current packet.

    "When the station has transmitted for a full slot time without seeing
    the 'Multiple_Senders' signal, then it knows that it has succesfully
    captured the medium for transmitting its packet."

So when the previous poster said "35% load, 1% col..." (oops! don't *USE*
that word!) he really meant, "35% load, and on average 1% of the packets
required two attempts to capture the cable."  (I say "two attempts", because
with that low 1% "capture retry" rate, almost all capture retries would
have succeeded on the second attempt.)

Yes, one can indeed describe Ethernet without using the "c........" word.


-Rob

-----
Rob Warnock, MS-9U/510		rpw3@sgi.com
Silicon Graphics, Inc.		(415)390-1673
2011 N. Shoreline Blvd.
Mountain View, CA  94043

Newsgroups: comp.dcom.lans.ethernet
From: u009@csx.cciw.ca (G. Stewart Beal)
Subject: Re: Netware shell obj for 3C501 card
Organization: Canada Centre for Inland Waters
Date: Fri, 9 Oct 1992 23:19:33 GMT

In article <92283.080303RBYAML@rohvm1.rohmhaas.com> Aengus Lawlor <RBYAML@rohvm1.rohmhaas.com> writes:

>I've seen some posts that 3Com have an FTP server available for anonymous ftp
>access. Try FTP.3COM.COM, or maybe just 3COM.COM. They should have all the
>drivers and diagnostics for their cards there.
>
>(The post I read mentioned that the site was experimental, and encouraged
>users to contact 3Com and say how useful it was, so that 3COM would keep it
>up).
>
I think the site is GATEKEEPER.3COM.COM and you'll have to dig around
a bit. Archie will identify where if you ask for the module name
you currently have.

Regards, Stu Beal, VE3MWM, u009@cs.cciw.ca,
National Water Research Institute.

We had survived another nuclear winter, and the
lawn had just trapped and eaten it's first robin.

Xref: sparky comp.dcom.lans.ethernet:2179 comp.dcom.lans.misc:819
From: pustule@cats.ucsc.edu (Thaddeus H. Wood)
Newsgroups: comp.dcom.lans.ethernet,comp.dcom.lans.misc
Subject: NI5010 Drivers Needed!
Date: 11 Oct 92 23:05:28 GMT
Organization: University of California; Santa Cruz
NNTP-Posting-Host: am.ucsc.edu


Greetings.  I am in desperate need of a 10net release
5 NI5010 driver, and I would also appreciate it if
I could acquire a NI5010 Netware Lite driver.  So,
whereabouts of either of the drivers, or possibly
acquisition thereof, would be tremendously appreciated.

Thanks.

--
Thad
From: voelker@ls12w (Matthias Voelker)
Newsgroups: comp.dcom.lans.ethernet
Subject: reusable coax-cable-connectors
Date: 14 Oct 1992 12:58:55 GMT
Organization: CS Department, University of Dortmund, Germany
NNTP-Posting-Host: ls12w
X-Newsreader: Tin 1.1 PL4

thanks for your reply to my news-posting concerning coax-cable and
ethernet. I think I didn't pose my question straighforward enough:

"I have: A PC, an ethernet card (Standard NE1000).
 I want: connect to thick, thin, twisted pair (each of them!) ethernet
         cable with the least possible destruction many times.

 So what do I need?"



Is this somewhat clearer? I'd like to have your opinion on that,
especially on the thick-to-thin converter (where to get).
To your knowledge, are there any connectors available yet which
connect by pure induction. I learned that a coax cable cannot be
isolated perfectly, so maybe one can connect (and I want to connect
only PASSIVELY, i.e. I dont want to send packets, just READ packets)
and amplify the signals before processing them?


Frank-Uwe c/o
==============================================================================
Matthias Voelker                    email:
Weisse Taube 8                      voelker@ls12w.informatik.uni-dortmund.de
D-4600 Dortmund 50 (Germany)        voelker@ls12w.uucp
Phone: (+49) 0231 734722            ...uunet!mcsun!unido!ls12w!voelker
==============================================================================
Newsgroups: comp.dcom.lans.ethernet
From: vjs@rhyolite.wpd.sgi.com (Vernon Schryver)
Subject: Re: Kalpana Etherswitch
Organization: Silicon Graphics, Inc.  Mountain View, CA
Date: Mon, 12 Oct 1992 00:12:59 GMT

In article <1992Oct11.194519.11411@netcom.com>, seifert@netcom.com (Rich Seifert) writes:
> In article <1992Oct7.170659.28586@ucsu.Colorado.EDU>, barr@tramp.Colorado.EDU (BARR DOUG) writes:
> > We have a subnet that is quite full (35% average usage during working hours
> > and 85% peaks). We are considering using a Kalpana ether switch to divide
> > up the traffic. I understand that the Kalpana has fixed some of the earlier
> > problems. Does anyone have any experience with this bridge (etherswitch)?
> > 
> > 
> 
> Remember that the switch will help you ONLY if the traffic patterns are
> "many-to-many", rather than "workstation-to-server". The switch will
> relieve this type of network congestion, but won't help you if a
> server is at all the bottleneck. 


Not literally true, unless "won't help" can mean "will hurt."
(I'm sure Rich Seifert knows that, but is just being nice.  I don't
suffer from that handicap.)

This has been discussed here before.

Such hubs hide the collisions that transmitters would otherwise see.
If you have a lot of "many-to-one" traffic, when the "many" try to send
a lot fo traffic at 1MByte to the "one" ethernet stubb, perhaps because
the machines are using 60K TCP windows, the many will not see any
collisions and will transmit all they have at full speed.  The
buffer(s) in the hub will eventually overflow, forcing the hub to
dropping packets.

Each dropped packet on a LAN is a catastrophy for high speed.  It
implies a timeout, and eventually retransmission of at least the lost
packet and often (e.g. with TCP) all of the packets after the lost
one.

Yes, TCP "slow start" will tend to keep the hub at the edge of
"congestion collapse", just as if they were routers.  However, that can
be terrible if you thought you were improving performance, because of
the timeouts.  (Of course, all bridges including bridging hubs are just
as much routers as any other; it is only that they route based on
6-byte MAC addresses and should be using spanning tree insteald of IP,
DECNET, OSI, XNS, etc addresses with RIP, OSPF, etc.)

The trouble is as always that collisions are good, and part of the
ethernet flow control mechinism.  Reducing the collision rate on
ethernet is necessarily any wiser than disconnecting RTS/CTS on a high
speed async modem.

(Was the Kalpana the hub that was not using spanning tree?  If so,
have they fixed that?)


Vernon Schryver,  vjs@sgi.com
Newsgroups: comp.dcom.lans.ethernet
From: rad@cix.compulink.co.uk (Richard Develyn)
Subject: No subject 
Reply-To: rad@cix.compulink.co.uk
Date: Thu, 15 Oct 1992 11:35:13 +0000

Redundant Link Management
Could someone please inform me whether partitioning in multi-port 
repeater hubs can be used to set up redundant links in a network. I 
understand that this is not advisable, but I dont really know why.
--

Richard Develyn from Hastings, Sussex, England ( rad@cix.compulink.co.uk ).
Software engineer (datacomms) for Cray Network Systems. Married to Caroline.
Hobbies: Dr Who, FRPG, SF, Curry, quality computer games, phylanthropic
discussions.
Organisation: European Space Operation Centre (E.S.O.C)
Date: Wednesday, 7 Oct 1992 15:33:26 CET
From: <RHUNTER@ESOC.BITNET>
Newsgroups: comp.dcom.lans.ethernet
Subject:    packet drops on repeaters?


I used to think that I understood repeaters. Now I know I don't.

We run a number of fairly small repeated LANS based on FibreMux
10 base-T hubs over IBM STP & fibre, connected to our internet
using Ethernet Interfaces on Ciscos. (These hubs are switch
selectable to 150 Ohm termination, and the transceivers we use
are also suitable for STP according to the vendor, so no flames
here please.)

We have come across a problem running LAVC on one of our LANS.
This LAN has only 15 machines attached... 13 Vaxes, 1 Cisco AGS,
& 1 DEMSA (DEC router) . It is spread over 4 Fibremux hubs
(say ABCD). Hub D acts as a central point in a star of fibre for
ABC, so there is no more than 2 repeaters between any 2 stations.

We have noticed that the VAX Ethernet Interface statistics
(result of using DEC NCP 'show active line counters') show that
98 out of 100 packets are sent no collision, approx 1 in 100
packets is sent after 1 collision, & also 1 in 100 after 2 or
more collisions. This is similar on all machines. I would have
thought the figure for 2+ collisions would be very much lower
(comments?) SQE is turned on for all transceivers since VAXes are
Ethernet V2.

Sniffers show utilisation at approx 5% bandwidth steady with rare
peaks of 18% ... in other words deathly quiet.

Sniffers also show between 1 in 100 & 1 in 1000 packet sent on
one of the satellite hubs (ABorC) is not received at the central
hub (D). Our supplier says "The failure rate of dropped packets
should be not unnormal. The rate is very dependend of packet size
and tansmit intervals." (sic)

I always thought a standard repeater would send a jam back to the
originating station over the fibre if there was a remote
collision, which would mean packet losses in the order of say 1
in a million.  Comments?

Anyone any low level LAVC experiences?
I don't mind getting flamage as long as I learn!

##############################################################
Ray Hunter               #    "Only Chemists Write Letters"
RHUNTER@ESOC.BITNET      #           Dostoyevsky.
Network Engineer         #
Marcol Communications    #    "I'd have been Raskolnikov,
on contract to           #  but Mother Nature ripped me off"
European Space Agency.   #           Howard Devoto
###############################################################
From: seifert@netcom.com (Rich Seifert)
Newsgroups: comp.dcom.lans.ethernet
Subject: Re: Kalpana Etherswitch
Date: 11 Oct 92 19:45:19 GMT
Organization: Netcom - Online Communication Services  (408 241-9760 guest)

In article <1992Oct7.170659.28586@ucsu.Colorado.EDU>, barr@tramp.Colorado.EDU (BARR DOUG) writes:
> We have a subnet that is quite full (35% average usage during working hours
> and 85% peaks). We are considering using a Kalpana ether switch to divide
> up the traffic. I understand that the Kalpana has fixed some of the earlier
> problems. Does anyone have any experience with this bridge (etherswitch)?
> 
> 

Remember that the switch will help you ONLY if the traffic patterns are
"many-to-many", rather than "workstation-to-server". The switch will
relieve this type of network congestion, but won't help you if a
server is at all the bottleneck. 

-- 
Rich Seifert                    Networks and Communications Consulting
seifert@netcom.com              (408) 996-0922
                                (408) 996-2860 FAX
"... specialists in Local Area Networks and Data Communications systems"
Newsgroups: comp.dcom.lans.ethernet
From: pwilson@gandalf.ca (Paul Wilson(Toronto-Sales))
Subject: Re: Kalpana Etherswitch
Organization: Gandalf Data Ltd.
Distribution: na
Date: Thu, 15 Oct 1992 20:01:44 GMT

In <STREETER.92Oct14153143@osgood.sanders.lockheed.com> streeter@osgood.sanders.lockheed.com (Ken Streeter) writes:

>In article <1992Oct7.170659.28586@ucsu.Colorado.EDU> barr@tramp.Colorado.EDU (BARR DOUG) writes:

>some time for an ethernet monitor providing a few statistic-gathering
>functions, but haven't been able to find quite what I'm looking for:

>  1) Measure both average load, and peak load over some time period.
>  2) Log the results of 1 (average,peak over time period) to file
>  3) Such a tool is free (either public domain, or copyrighted)
>  
>Ideally, the tool would find average load, and peak load over, say
>5-minute timeslices, and log the information to a file.  If this were
>run for a month, it would give provide information as to when peak
>network usage occurs, and how much of the network is being used.

Many of the network devices out there today are manageable devices using
SNMP.  Of course, this requires a certain amount of intelligence be present
in the device, but this is more commonplace now.  If you look at network
management software that is available now, you will find that some packages
are able to poll particular devices for SNMP information.  It is therefore
possible to poll a device (like a 10BaseT hub for instance) to measeure
the current value in the particular counter.  From this you can derive
delta values, etc.  

My example is pretty simple, but the approach allows a fair degree of 
complexity.  The principles are sound and working in at least one commercial
product on the market today ( for example, ours :-)

paul

--
Paul Wilson 416 698 3649
pwilson@gandalf.ca
From: pat@hprnd.rose.hp.com (Pat Thaler)
Date: Sun, 11 Oct 1992 14:01:25 GMT
Subject: Re: 10BaseT != 3-Com Multiconnect (interesting stuff)
Organization: HP Roseville Networks Division
From: rich@theophilus.msfc.nasa.gov (Rich Krum)
Subject: Re: reusable coax-cable-connectors
Reply-To: rich@theophilus.msfc.nasa.gov
Organization: Boeing Computer Support Services
Date: Tue, 13 Oct 1992 17:56:04 GMT

Precisely the problem--a thin stub without a proper thick to thin convertor
produces echos and standing-waves on the thick ethernet cable.  Remember that
10 Mhz baseband signals on the thick ethernet cable have some radical harmonics
that must not be allowed to bounce around.  That is why the cable is (MUST BE)
terminated on BOTH ends with a proper terminator.  This stuff is, in fact RF,
and behaves like it. (I started out with a EE degree before I started into CS)

There are several gadgets made that will connect (vampire style) to the thick
cable and convert to thin--try one of those--

BTW the tuned stub problem is why thin uses two cables and a tee fitting--that
minimizes the stub.  Some patent type cables just look like a single coax, but are
actually two in a single jacket--a bit expensive for my taste.

--rich 

---
----------------------------------------------------------------------------
"My opinions are my own, and my employer (Boeing Computer Support Services)
 denies any responsibility for me, all opinions in general, and anything 
 I may say, do, or be otherwise associated with outside of work for them.
 -- Use at your own risk, your mileage may vary, no news is good news."

 E-MAIL REPLY TO:  rich@troll1.msfc.nasa.gov     PLEASE KEEP IT "G" RATED
----------------------------------------------------------------------------

Newsgroups: comp.dcom.lans.ethernet
From: vjs@rhyolite.wpd.sgi.com (Vernon Schryver)
Subject: Re: Kalpana Etherswitch
Organization: Silicon Graphics, Inc.  Mountain View, CA
Date: Mon, 12 Oct 1992 00:21:28 GMT

>| In article <1992Oct7.170659.28586@ucsu.Colorado.EDU>, barr@tramp.Colorado.EDU (BARR DOUG) writes:
>|>    ....   We are considering using a Kalpana ether switch to divide
>|> up the traffic....


Besides the serious bad effects of "many-to-one" traffic patterns with
such hubs, there is another other minor problem but great annoyance to
some of us from such hubs.

The annoyance is shared with any other bridge or router.  It is that
snooping on the ethernet tends to become boring.  When looking for
protocol problems with an EtherSniffer or similar product (e.g. my
employer's), or just trying to find out who is beating up a server,
you're quite likely to not see anything at all of interest.  That is
because the bridges keep the "irrelevant" traffic away.  The annoyance
is worse with these new fangled hubs, because you tend know the
topology with bridges, but people use the hubs break the ethernet net
up into such small chunks that no one knows which machines are on the
same stub.


Some people find this is a desirable security enhancement, because it
makes snooping harder.


Vernon Schryver,  vjs@sgi.com
From: nelson@crynwr.com (Russell Nelson)
Newsgroups: comp.dcom.lans.ethernet
Subject: Wanted: Packet driver for 3Com's new 3C509 ethernet card 
Distribution: world
Date: Wed, 14 Oct 92 22:47:50 GMT
Organization: Crynwr Software

In article <1992Oct14.154310.25038@sol.ctr.columbia.edu> lindh@uhasun.hartford.edu writes:

   We have some new 3C509 cards on the way and I can't seem to
   find a packet driver for them. We use the standard (FTP's)
   packet drivers for everything....Novell,DV/X,FTP,PC-NFS,NCSA,PCIP,etc...
   The cost and speed make them the best choice for networking, but I
   need a packet driver before this can become the new 'standard' card.

           Where can I get a standard packet driver?

It will be on simtel20.army.mil and mirrors.

           If not now, then when can I get it?

10/26, assuming it passes the beta test.

           Will an existing driver work with the 3C509?

No.

-russ <nelson@crynwr.com> I'm proud to be a humble Quaker!
Crynwr Software           Crynwr Software sells packet driver support.
11 Grant St.              315-268-1925 Voice  |  LPF member - ask me about
Potsdam, NY 13676         315-268-9201 FAX    |  the harm software patents do.
From: jim@mivax.mc.duke.edu (James D Dryfoos - Systems)
Newsgroups: comp.dcom.lans.ethernet
Subject: Packets containing all F's???
Date: 16 Oct 92 19:30:00 GMT
Organization: Duke University Medical Center
News-Software: VAX/VMS VNEWS 1.41

We occaisonally get bursts of packets (50-200) which contain

00FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF

where the amounts of F's varies.  The packet does have a good CRC.
I suspect a bad device, but wanted to see if anyone has seen this
before.  Locating the bad device is daunting, since everything works
and the failure would have to be intermittent.

-Jim 

*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*
*  James Dryfoos  -- Medical Informatics - Duke University Medical Center     *
*                                                                             * 
*  VMS Systems Programmer -- Postmaster - Duke Electronic Medical Post Office * 
*  dryfo001@mc.duke.edu - dryfo001@dukemc.bitnet                              *
*  Box 2914 Durham NC, 27710 USA - EARTH (919) 684-6421
*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*

   =======================================================================
      James D. Dryfoos                  |  dryfo001@mc.duke.edu
      Duke University Medical Center    |  dryfo001@dukemc.bitnet
      Box 2914 DUMC                     |  (919) 684-6421 - office
      Durham, NC 27710 Earth            |  (919) 684-8675 - fax
   =======================================================================