HDTenEightyP/NetNews huggingface dataset:
From: rpw3@rigden.wpd.sgi.com (Rob Warnock)
Newsgroups: comp.dcom.lans.fddi
Subject: Re: Still a little confused
Date: 7 Oct 92 11:00:51 GMT
Organization: Silicon Graphics, Inc.  Mountain View, CA

myoung@force.ssd.lmsc.lockheed.com writes:
+---------------
| I am still a little confused about concentrators and rings.
| Is the general usage for FDDI to use a concentrator? Or do
| users generally build physical rings?
+---------------

It varies wildly depending on the environement. Some users mix the two.

+---------------
| And of course the follow up:  If they use a concentrators, then why
| pass tokens out to the stations, when the token can be passed about
| inside the hub?
+---------------

Uh... Unless you pass the token to the stations, how're they gonna know
when they can transmit?  That's what the tokens are *for*.


-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.fddi
From: cgd@ecmwf.co.uk (Dick Dixon)
Newsgroups: comp.dcom.lans.fddi
Subject: Re: Optical Bypass Switches.
Date: 15 Oct 92 07:18:16 GMT
Organization: ECMWF


> Optical Bypass switches are extremely simple devices, just
> manufactured to
> some very exacting standards. 
.
.
> -- 
> Bryan Duff
> Network Engineer
> Network Systems Corp.

Network Systems ships its major FDDI equipment with integral bypasses. 
Do you find them in
general to be reliable?  Some vendors (esp. DEC) swear that bypasses are
Bad News (but
I suspect that they are a teensy bit influenced by their available
product range).

				Dick Dixon
Newsgroups: comp.dcom.lans.fddi
From: xxseub@wyvern.lerc.nasa.gov (Steven Eubanks)
Subject: MIC M at Wall?
Reply-To: seubanks@lerc.nasa.gov
Organization: NASA- Lewis Research Center
Date: Wed, 7 Oct 1992 21:03:10 GMT

Forgive the question if the answer is obvious, but can I assume that a
FDDI wall connectors/terminations for single attach stations should be 
keyed as M?  The ANSI PMD document never specifically mentions keying at
the wall.  Thanks.

Steve
-- 
Steven W. Eubanks,  Telecomm & Networking 	NASA Lewis Research Center
Internet:seubanks@lerc.nasa.gov			21000 Brookpark Rd.,MS 142-1
(216)433-9479					Cleveland, OH  44135

Newsgroups: comp.dcom.lans.fddi
From: koning@koning.enet.dec.com (Paul Koning)
Subject: Re: Is dual homing easy?
Reply-To: koning@koning.enet.dec.com
Organization: Digital Equipment Co., distributed systems architecture
Date: Thu, 8 Oct 1992 14:42:37 GMT


In article <92281.150913DART@SLACVM.SLAC.STANFORD.EDU>, DART@SLACVM.SLAC.STANFORD.EDU (415) writes:
|>I need some advice on dual homing.  I want to use DH, Dual Homing,
|>to satisfy a conflict; our users want redundant access to some
|>servers on the FDDI and, even though the servers have DAS cards,
|>I don't want them on my main ring.  What I was planing on doing
|>as a fix was cross couple the stations across two concentrators,
|>which I understand is called dual homing.   This is a picture of
|>what I want to do.  Can I just plug these guys in and expect them
|>to work this way?
|>...
|>Thanks,
|>Marty Dart.
|>
|>My opinions are mine and mine alone.

What you described is fine, and that certainly is a good solution for the
requirements you've been given.

Will it work?  It should, but to be sure you might confirm it with the
supplier of the DAS cards (the ones in your server) to make sure their
SMT firmware supports dual homing.  The concentrators won't be an issue;
they just see a connection and don't know or care whether it's a dual
homing setup below them.

	paul
From: vjs@rhyolite.wpd.sgi.com (Vernon Schryver)
Newsgroups: comp.dcom.lans.fddi
Subject: Re: Can NFS over FDDI work properly?
Keywords: NFS, FDDI
Date: 7 Oct 92 23:37:38 GMT
Organization: Silicon Graphics, Inc.  Mountain View, CA

In article <1992Oct7.150707.29127@awdprime.austin.ibm.com>, will@vulcan.austin.ibm.com (Will Fiveash) writes:
> In article <qncmi00@rhyolite.wpd.sgi.com> vjs@rhyolite.wpd.sgi.com (Vernon Schryver) writes:
> >The only IP fragmenting that an FDDI-ether bridge will usually need to
> >do is of UDP packets.  UDP packets are datagrams, and have no sequence
> >numbers of any kind.  If you don't have FDDI-ether-FDDI networks, the
> >initial MSS negotiation in TCP will pick 1500.  This is consistent with
> >the TCP/IP lore (and RFC) that considers fragmenting harmful.
> 
> I am somewhat confused about the statement concerning MSS negotiation.
> My understanding was that if the two connecting systems were on the
> same physical network then the MSS was the MTU of the interface -
> TCP/IP header length.  If they were not on the same physical net, i.e.
> router(s) involved, then the MSS was 536.  This is what I am reading
> from Doug Comer's book "Internetworking with TCP/IP".

Are we disagreeing?  I don't think so.

As I understand BSD style code and the standards,
    -each system should use an MSS that is no larger than the MSS
	negotiated with the MSS option.

    -two systems on the same wire using the same IP network number
	should use the MTU appropriate for the common wire.

    -a pair of systems on different (sub)networks should consider
	using a smaller maximum segment size to prevent fragmentation
	in the gateways between their (sub)networks.  The smaller
	number may be as small as the minimum legal IP maximum packet
	size, which is a lot smaller than 512.  (I've forgotten.)

    -the classic "smaller" size is >= 512 and <= 576.  Notice that
	536 is 40 less than 576.  40 is the familiar TCP/IP magic
	number, the sum of the sizes of a TCP header and an IP header
	without options.

    -it does not matter what physical network the two systems are on.
	The 500 MSS has to do with being on the same IP or logical
	network.  Bridges are invisible and (must be) irrelevant,
	unless they connect a host on one medium with one MTU to
	another host on another medium with a different MTU.

If I were not lazy, I'd go look up RFC chapter and verse.  I vaguely
recall that H.R. has relaxed the "should ... 5xx".  Maybe not.

I do think they say that the systems are free to choose a larger size
if they can avoid causing fragmentation.  After all, that's what "MTU
discovery" is all about.  It is also the purpose of the
"allnetsarelocal" and "allsubnetsarelocal" switches in BSD code.

Using ~500 when you could have used 1500 does terrible things to
performance.  It bogs down gateways not only with 3 times as many data
packets at up to the 3 times the data packet rate, it also as much as
triples the number of TCP ACK's flowing in the opposite direction.

Using ~500 when you should have used >=4K would be an abomination.


Vernon Schryver,  vjs@sgi.com
From: carr@acsu.buffalo.edu (Dave Carr)
Newsgroups: comp.dcom.lans.fddi
Subject: Wellfleet and 3Com interoperability
Date: 16 Oct 92 16:38:10 GMT
Article-I.D.: acsu.Bw83Jn.IB3
Organization: UB


    Presently on campus we have a FDDI ring connecting all of our routers.  At
the moment all of the routers we have on campus are Wellfleets.  What I'm 
interested in finding our is how well do 3Coms Netbuilder IIs work with the
Wellfleets.  I'm going to need to route IP, Lat and IPX over the FDDI.  Any
experiences with the 2 companys interoperability would be great help. 


                       Thanks,

                        Dave


David Carr                                               104D Computing Center 
carr@otto.cit.buffalo.edu                     University of New York at Buffalo
-- 

David Carr                                               104D Computing Center 
carr@acsu.buffalo.edu                        University of New York at Buffalo
Newsgroups: comp.dcom.lans.fddi
From: myoung@force.ssd.lmsc.lockheed.com
Subject: Re: Still a little confused
Reply-To: myoung@force.ssd.lmsc.lockheed.com
Organization: LMSC, Sunnyvale, California
Date: Wed, 7 Oct 92 21:38:49 GMT

In article <qph7hls@sgi.sgi.com>, rpw3@rigden.wpd.sgi.com (Rob Warnock) writes:
>myoung@force.ssd.lmsc.lockheed.com writes:
>+---------------
>| I am still a little confused about concentrators and rings.
>| Is the general usage for FDDI to use a concentrator? Or do
>| users generally build physical rings?
>+---------------
>
>It varies wildly depending on the environement. Some users mix the two.
>
>+---------------
>| And of course the follow up:  If they use a concentrators, then why
>| pass tokens out to the stations, when the token can be passed about
>| inside the hub?
>+---------------
>
>Uh... Unless you pass the token to the stations, how're they gonna know
>when they can transmit?  That's what the tokens are *for*.
>
>
>-Rob
>
You caught me; I was asking a loaded question.

The token serves two purposes, which in a physical ring are combined:
1) The allow some implicit flow control, and
2) The control the distributed switch function.

In a hub switch, the two functions can be separated.  One can
add some buffering, and then let each line have its own asynchronous
token passed between the desktop and hub, signaling for data when
the buffer is near empty.

Meanwhile, the switch can have its own round robin token, taking
data from each hub interface buffer and switching it accordingly.

I wanted to see if any thread develops along this line of thinking.

Matt
From: bryand@cascade.ens.tek.com (Bryan Duff)
Newsgroups: comp.dcom.lans.fddi
Subject: Re: Optical Bypass Switches.
Date: 13 Oct 92 20:06:30 GMT
Article-I.D.: cascade.1bfa86INNi7a
Organization: Tektronix, Inc., Beaverton,  OR.

In article <1992Oct12.160456.11141@walter.cray.com> hens@snipe.cray.com (Tom Stephens) writes:
>
>
>Can someone tell me how they really work?  Or better yet, point me in a direction where I can read about them?  I am having problems explaining that if two machines are powered off in an fddi ring, they will not isolate the machine in the middle.  Senerio..
[ Senerio deleted to save space]
>---------------------------------
>Tom Stephens
>Corporate Computing and Networks, Chippewa Falls, WI
>Cray Research Inc.  hens@cray.com

Optical Bypass switches are extremely simple devices, just manufactured to
some very exacting standards.  During normal operations a selonoid holds a
concave mirror is a position to reflect light from and to the ring into
fibres that contain the machines receivers and transmiter circuits.  When the
machine is powered off the mirror moves a fraction of on inch (pulled back 
by a spring) causing the light to be transmitted directly from the Primary/
Secondary in to the Primary/Secondary out respectively.  A second type of
bypass switch actually moves little U-shaped fibers to route the
light in the proper direction, but once again is controlled by a selonoid.

I hope this helps a little, it really is hard to explain without a 
visual aid.

Bryan Duff
EIC
Network Systems Corp.  bryand@cascade.ens.tek.com
 
-- 
Bryan Duff
Network Engineer
Network Systems Corp.
From: craa85@ccsun.strath.ac.uk ( D.W.Stevenson)
Newsgroups: comp.dcom.lans.fddi
Subject: FDDI analysers
Date: 13 Oct 92 08:24:08 GMT
Organization: University of Strathclyde

I'm interested in information about FDDI analyser's. Can anyone give me a list
of vendors who produce this equipment?

-- 
Dave Stevenson 				d.w.stevenson@strath.ac.uk
Computer Centre Communications		Tel : 44 41-552 4400 ext 3461
University of Strathclyde
Glasgow, Scotland, U.K. 
Newsgroups: comp.dcom.lans.fddi
From: pettengill@cvg.enet.dec.com ()
Subject: Re: How perform 30+ Workstation on FDDI?
Reply-To: pettengill@cvg.enet.dec.com ()
Organization: Digital Equipment Corporation
Date: Wed, 14 Oct 92 02:06:21 GMT


In article <1992Oct10.131926.1@elgr.epfl.ch>, grandjean@elgr.epfl.ch writes:
|>
|>     We are evaluating multiple ethernet segment  vs  FDDI.
|>

Assuming that you have reasonable adapters, FDDI will buy you a lot
more than 10 Ethernet segments connected by a switch; figure that you
only get 30 megabits out of your FDDI adapter (I'd call that a dog).
If there is no contention, then you'll move data at 3 times the rate
as you can on Ethernet.  If there is contention, you get the same total
data rate as if you had 10 Ethernet segments where the traffic was all
local; but if the traffic is all going thru a switch and optimally
balanced, then you'll need 20 Ethernet segments to get the same total
thruput as a single FDDI segment.

It's all simple queuing theory: a single k unit server is always better
than k single unit servers.  (Of course, the complex part of the theory
is dealing with the bottlenecks that every system ends up with because
life isn't as simple as theory needs life to be.)

|>Does anyone have experience with 30+ networked workstations with FDDI?
|>What are the issue on management and upgradability?

I don't have experience with workstations, but in testing 10+ `servers'
on FDDI, FDDI has its faults, ie., there is a lot more overhead than
when using proprietary interconnects (CI, DSSI), but the performance is
generally about equal and the flexibility and cost better.

|>Is there somewhere on the NET performance figure of such configuration
|>(DEC & SUN hardware)?

There was an article in the DEC Technical Journal that focused on FDDI
that reported on benchmarking the DECcontroller 700 on a DECstation 5000.
However, unless you have easy access to this journal, I don't think its
worth tracking down these days; it is getting rather dated.

|>
|>Thanks for anyone who can make the point clearer.
|>--
|>Daniel Grandjean, Swiss Federal Institute of Technology        __  __
|>Address:     EPFL SI-DGR, CH-1015 Lausanne, Switzerland       |  \/  |
|>E-mail:      grandjean@elgr.epfl.ch                           |o ()o _
|>Phone:       +41 21 693 27 24	(Central European Time)       |__/\__/
|>Fax:         +41 21 693 27 27                                    __
|>


mulp
DEC - CVG cluster busters
From: DART@SLACVM.SLAC.STANFORD.EDU (415)
Newsgroups: comp.dcom.lans.fddi
Subject: Is dual homing easy?
Date: 7 Oct 92 23:09:13 GMT
Organization: Stanford Linear Accelerator Center

I need some advice on dual homing.  I want to use DH, Dual Homing,
to satisfy a conflict; our users want redundant access to some
servers on the FDDI and, even though the servers have DAS cards,
I don't want them on my main ring.  What I was planing on doing
as a fix was cross couple the stations across two concentrators,
which I understand is called dual homing.   This is a picture of
what I want to do.  Can I just plug these guys in and expect them
to work this way?
  *
  *  ------------------                       -------------
  ***|A               |***********************|A          |
     | Concentrator 1 |                       |  SERVER 1 |
  ***|B               |                      *|B          |
  *  ------------------                    *  -------------
  *                                     *
  *                                  *
  *->(Main Ring)                  *
  *                            *
  *                         *
  *  ------------------  *
  ***|A               |*
     | Concentrator 2 |
  ***|B               |
  *  ------------------
  *
Thanks,
Marty Dart.

My opinions are mine and mine alone.
Xref: sparky comp.dcom.lans:1940 comp.dcom.lans.ethernet:2181 comp.dcom.lans.fddi:706
From: saleh@cse.uta.edu (Medhat Saleh AbdelHady)
Newsgroups: comp.dcom.lans,comp.dcom.lans.ethernet,comp.dcom.lans.fddi
Subject: Question about token ring bridge.
Date: 12 Oct 92 02:07:04 GMT
Organization: Computer Science Engineering at the University of Texas at Arlington

I'm posting this article on behalf of a friend : 


I have some problems bridging two IBM token rings together.

We have two token ring network running at two different buildings.  We try to 
use fiber optic cable to bridge them together.  The problem is the cable come 
out of the LAM on both side is T1 type.  Is there a device that converts it
into fiber optic?

We have AS/400 and PCs on both rings.  What kind of hardware and software do
we need to do the bridge?

I'm not very familiar with bridge and router.  Are there any books and
technical references that discuss in details about bridge hardware products
as well as software protocals? 

 Yunhui Yang
-- 


    Medhat  M.  Saleh
Xref: sparky comp.dcom.lans:1947 comp.os.msdos.misc:5683 comp.protocols.tcp-ip:4786
From: josevela@mtecv2.mty.itesm.mx (Jose A. Vela A.)
Newsgroups: comp.dcom.lans,comp.os.msdos.misc,comp.protocols.tcp-ip
Subject: Re: Clarkson Token-Ring Packet Driver on PcRoute ver 2.4
Date: 16 Oct 92 17:23:24 GMT
Followup-To: comp.dcom.lans
Organization: I.T.E.S.M. Campus Monterrey



 yes I used it, and it works perfectly 

 mmm try your token ring card with a TCP program : ping , telnet, 

 and make shure it works ..

 everything must work as exactly as any other packet driver ..

 good luck

 _____________________________________________________________________________
 Jose Angel Vela Avila.
  Instituto Tecnologico y de Estudios Superiores de Monterrey
    I.T.E.S.M    Mexico.
  ___               _    ___  _         __   josevela@mtecv2.mty.itesm.mx
 (   >             ' )  /    //        /  )  
  __/________    _  (  / _  // __.    /--/  
 / /  (_)  \_)__</_  \/ </_</_(_/|_  /  ( o  NetStorm <--- irc Nick 
<_/

Newsgroups: comp.dcom.lans.hyperchannel
From: zawada@ncsa.uiuc.edu (Paul Zawada)
Subject: Re: Preformance with PCF ?
Organization: Nat'l Ctr for Supercomp App (NCSA) @ University of Illinois
Distribution: inet
Date: Fri, 16 Oct 1992 13:06:45 GMT

In article <"443*.G=Arne.S=Langmo.OU=runit.O=sintef.PRMD=uninett.ADMD=..C=no."@MHS>, Arne.Langmo@RUNIT.SINTEF.NO (Arne Langmo) writes:
|> We have a remote site connected to our Cray YMP via:
|> 
|> Low-speed-channel -> DX4130 -> FDDI -> DX???? -> E3 -> DX???? -> Ethernet
|> 
|> In this config. there are set up three PCF filters on the link boxes, to
|> limit the access from FDDI to remote site.
|> There are no big error-rates logged on any interface.
|> 
|> Thru this config. they get a preformance of 80-90 kbits/s with FTP from
|> the Cray to a Convex on the ethernet!
|> 
|> I have seen that some kinds of PCF filters can slow down a NSC-router a bit.
|> But can PCF-filters cause such a terrible loss of preformance?
|> 

As with anything, it depends on how it is implemented...  I've never 
seen this kind of degradation of performance, but it is probably possible.

I don't have any numbers to back this up, but I think we have seen that
you get better performance with PCF if you apply it to a specific interface,
rather than applying the filter on an IP number basis.  I would also 
think that applying a filter on "first" or "last" would give you better
performance than applying it on specific IP numbers...  

Also, do you mean you have three separate filters on each box?  This could 
also be a source of the problem...  In general, I try to combine filters
when they all work on the same task.  

--zawada

-- 
Paul J. Zawada                                    KB9FMN
NCSAnet Network Engineer                          zawada@ncsa.uiuc.edu
National Center for Supercomputing Applications   ..!pur-ee!zawada
From: Arne.Langmo@RUNIT.SINTEF.NO (Arne Langmo)
Newsgroups: comp.dcom.lans.hyperchannel
Subject: Preformance with PCF ?
Date: 13 Oct 92 09:45:25 GMT
Distribution: inet
Organization: The Internet

We have a remote site connected to our Cray YMP via:

Low-speed-channel -> DX4130 -> FDDI -> DX???? -> E3 -> DX???? -> Ethernet

In this config. there are set up three PCF filters on the link boxes, to
limit the access from FDDI to remote site.
There are no big error-rates logged on any interface.

Thru this config. they get a preformance of 80-90 kbits/s with FTP from
the Cray to a Convex on the ethernet!

I have seen that some kinds of PCF filters can slow down a NSC-router a bit.
But can PCF-filters cause such a terrible loss of preformance?

------------
Arne Langmo
SINTEF Runit
NORWAY
Newsgroups: alt.save.the.earth
From: whitmeye@den.mmc.com (Richard Whitmeyer 865-8497)
Subject: Re: Hydride storage tanks for hydrogen-electric car.
Originator: whitmeye@surf
Organization: Martin Marietta Astronautics, Denver
Distribution: usa
Date: Tue, 13 Oct 1992 03:59:20 GMT


In article <1332.1364.uupcb@spacebbs.com>, howard.smith@spacebbs.com (Howard Smith) writes:
|> American Hydrogen Association
|> Silicon Valley Chapter
|> 1401 Point Claire Court
|> Sunnyvale, CA 94087
|> Dept: Hydrogen-Electric Car Project
|>                                                       Page 1 of 3
|> 
|> 
|> The  Silicon Valley chapter of the American Hydrogen  Association
|> (AHA-SV)  has designed a hydrogen fueled, electric powered,  com-
|> muter automobile which is to have a 1000 mile range on one charge
|> of  hydrogen, and proposes to build such a car for all the  world
|> to  see.  However,  there seems to a shortage  of  the  essential
|> hydrides (and fabricators of these  hydrides) needed to store the
|> hydrogen  in the vehicle. The following, therefore, is a call  to
|> someone or to some organization that can manufacture or knows  of
|> a  possible  manufacturer of these hydrides in quantities of  600
|> lbs. (263 kg) or more.

This may be old news to you folks. 
Try Roger Billings, Billings Energy Corp., Provo Utah
He's big on hydrogen and fuel cells and cars.

Rich Whitmeyer
From: ez007856@hamlet.ucdavis.edu
Newsgroups: alt.save.the.earth
Subject: Request address
Date: 8 Oct 92 03:22:10 GMT
Organization: Computing Services, UC Davis

Could anybody please give me the addresses of Greanpeace and the 
Sierra Club?  Thanks in advance.\

Edelmiro Salas
From: birchall@pilot.njin.net (Shag)
Newsgroups: alt.save.the.earth
Subject: Environmental Topics on Internet BBS system
Summary: shameless plug
Keywords: telnet-accessible
Date: 15 Oct 92 22:14:22 GMT
Organization: Screaming in Digital, the Queensryche Net Digest

The Prism BBS [telnet to bbs.fdu.edu, login as bbs] now has available the
following discussion areas:

Eco/Enviro			- General Ecological/Environmental Topics
Energy				- [Obvious]
Before 2000			- Emerging Technology
Alternate Transportation	- Bicycles, et cetera
Pollution & Clean-Up		- Pollution Prevention, Reduction, Removal
Recycling and Reuse		- Materials Recycling & Reuse

Some of the areas are quite new, and everyone's welcome.

-Shag
-- 

     Freedom belongs to only those without video screens for eyes and mouth.
		- Queensryche
Xref: sparky alt.save.the.earth:1266 alt.destroy.the.earth:712
From: de5@ORNL.GOV (Dave Sill)
Newsgroups: alt.save.the.earth,alt.destroy.the.earth
Subject: Re: Save the planet or mankind? (was Re: No looking at your neighbors' papers....)
Date: 14 Oct 92 13:33:41 GMT
Organization: Oak Ridge National Lab, Oak Ridge, TN

In article <1992Oct14.005922.11830@sol.ctr.columbia.edu>, locklin@titan.ucc.umass.edu () writes:
>
>A true enviornmentalist doesn't post to alt.destroy.the.earth

A true person with a brain doesn't post to alt.save.the.earth asking someone
not to post to alt.destroy.the.earth, but a true environmentalist might well
cross post to alt.destroy.the.earth when the honest question of whether/how
the Earth can be destroyed is involved.

>reminds me of christians posting to alt.satanism

Which is also quite a reasonable thing at times.

>go away please

No, thank you.

-- 
Dave Sill (de5@ornl.gov)           For every Bill Joy there is a Kirk McKusick.
Martin Marietta Energy Systems     For every Bill Gates there is a Richard
Workstation Support                Stallman.                     --Paul Graham
Newsgroups: alt.save.the.earth