HDTenEightyP/NetNews huggingface dataset:
From: rpw3@rigden.wpd.sgi.com (Rob Warnock)
Subject: Re: Computers dont like ATM?
Organization: Silicon Graphics, Inc.  Mountain View, CA
Date: Fri, 18 Dec 1992 06:18:07 GMT

In article <23082@venera.isi.edu> finn@dalek.isi.edu (Greg Finn) writes:
+---------------
| 	For short runs of byte wide twisted pair, some of the new
| differential drivers can produce at least 500 Mb/s payload for about
| $50/pair in handfull quantity.  Point-to-point runs of up to 30 meters
| buys you most of the office to wiring closet connections.
+---------------

30 meters is too short. The generally-accepted "desk to wiring-closet"
requirement is 100 meters, and even that is marginal. I know that we have
had some problems in-house with 10baseT runs way over 100 meters (yes,
from a desk to the nearest closet, and yes, the installer "shouldn't have
done that"). I would feel more comfortable with a link technology that
could run for "a few hundred" meters (say, 200-350).

+---------------
| >Well, the HIPPI market is looking quite eagerly at 622 Mb/s ATM (or so
| 
| 	The HIPPI market seems to be implementing HIPPI on Fibre Net.
| LLNL is moving that way.  The vendors are IBM, Honeywell, Psi Tech and
| Ancor.  Fibre Channel is specifically designed to handle the HIPPI
| payload as its upper-limit option, hence its attractiveness.
+---------------

Yes, LLNL is very vocal about their approach. Yet when you talk to other
HIPPI users besides LLNL, you get a different view. (The "Xunet" testbed,
for example, is using an ATM-based fabric.) I'm not sure how far one vocal
user can drive the market...

As some may have figured out by now, my *personal* preference in the LAN
would be for a form of Frame-Relay-like packet switching, much like the
ancient ARPAnet used between IMPs, but using ATM-like "fat cells".

[A "fat cell" is just a whole AAL5 PDU wrapped in a single LAN frame, with
a prototype 5-byte ATM cell header on the front for addressing. A "fat cell"
LAN would consist of point-to-point links from hosts to switches and between
switches, just like ATM. Switches are "frame relays"/bridges/routers/whatever.
"Fat cells" can be chopped into 53-byte ATM cells (or reassembled) in the
LAN-WAN gateway switches by replicating the prototype 5-byte header, allowing
transparent interoperability with remote ATM hosts.]

However, unless ATM-in-the-LAN dies a horrible death, I don't expect anything
like the "fat cell relay" notion to take off (or indeed, *any* link-level
technology that isn't "a standard"). Too bad...


-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.cell-relay
From: myoung@force.ssd.lmsc.lockheed.com
Subject: Another Network Service
Reply-To: myoung@force.ssd.lmsc.lockheed.com
Organization: LMSC, Sunnyvale, California
Date: Tue, 15 Dec 92 16:20:17 GMT

Cyclone, the name of BT's new global network service.  (Info Week)
I like the name, denotes a new paradigm.

The service will be anchored by a series of well placed switches, and
is designed to offer global interconnectivity without the hassles of
dealing with multiple carriers.  Good idea.

Wish List:

1) Let the service developers co-locate.  They need to put servers 
and application specific routers at key locations on the globe.

2) Maybe the developers do not need direct switch control, but they
do need exploratory capability about user defined spanning trees, 
multi-cast trees, and so on. 

3) Open up the wallet, invest in some leading edge, multi-vendor 
projects which add value to the network.

4) Give some bandwidth to the research community.
Newsgroups: comp.dcom.cell-relay
From: myoung@force.ssd.lmsc.lockheed.com
Subject: Re: Computers dont like ATM?
Reply-To: myoung@force.ssd.lmsc.lockheed.com
Organization: LMSC, Sunnyvale, California
Date: Fri, 18 Dec 92 16:46:11 GMT

In article <to6efqs@sgi.sgi.com>, rpw3@rigden.wpd.sgi.com (Rob Warnock) writes:

>[A "fat cell" is just a whole AAL5 PDU wrapped in a single LAN frame, with
>a prototype 5-byte ATM cell header on the front for addressing. A "fat cell"

  Is a great idea!

>However, unless ATM-in-the-LAN dies a horrible death, I don't expect anything
>like the "fat cell relay" notion to take off..

  Don't give up on this.  Beleive me if some breakthrough distributed
data application likes the fat cell, then all bets are off.


********************
Other Matters:

  I like shielded twisted pair.

  * Users are getting very good at pulling copper
  * Better impedance control
  * Better emmision control and less loss over distance

I liked the STP approach for FDDI.

What happens to cost of 100 Mbps over 100 Meters using STP and a
1 Gbps switch?
Newsgroups: comp.dcom.cell-relay
From: kyma@shell.portal.com (Matt J Young)
Subject: Signalling
Organization: Portal Communications Company
Date: Mon, 14 Dec 1992 02:30:52 GMT


  If we accept BellCore's and cisco's (Comm Week) idea that  some
more comprehensive resource management should be deployed for the
new networks, then the task is to define the depth at which  this
new management layer would operate.

  We would be particularly interested if the resource  management
layer  included  the discovery processes which are currently part
of PPP.  For instance, on a cold start, can this  new  management
layer directly interrogate nodes across physical links.

 PPP   does   not   define   multi-hop,    recursive     topology
discovery  and  lives  quite  will  over HDLC. The new management
layer  will execute recursive discovery, and  cannot  rely  on  a
standard  network  layer   for  its propagation, since that would
presume a prior discovery. Another problem being that the network
layer  itself  may  be  under diagnostics  and cannot be used for
transport.

  And the management layer  requires  capability  to  build  per-
sistent  tracks, as it will have to utilize multi-node structures
about  the  network.   Hence,  the  management  layer  has  local
pointers for its navigation, and does not use the managed network
layer.

  Without a traditional network layer, then what  has  it  for  a
transport layer, since its operation relies on reliable transfer?
If the new layer came complete with a standard transport  mechan-
ism,  then  our  choices  are  : 1) Strip out one of the standard
transport functions and default to this, 2) Use one of the  newer
transport  technologies,  3) Use an innocuous TP4. or 4) Redefine
TCP/IP to allow IP to represent local pointers only.

  Already, most of the possible mechanisms  have  been  mentioned
(partially   adapted   cells   or   fat  cells,  wave  languages,
OS bypass, SSCOPE,XTP, etc).  Possibly we should simply implement
a  solution and  use it to build a control layer for an arbitrary
router.  If successful, then it should prove  applicable  to  the
ATM problem.

Newsgroups: comp.dcom.cell-relay
From: ag@fokus.gmd.de (A. Gavras)
Subject: Re: ATM & SONET
Originator: ag@icarus
Organization: GMD-Fokus
Date: Mon, 14 Dec 1992 09:27:13 GMT

Newsgroups: comp.dcom.cell-relay
From: clarke@atri.curtin.edu.au (Nathan Clarke)
Subject: Re: WDM and ATM
Reply-To: clarke@atri.curtin.edu.au
Organization: Australian Telecommunication Research Institute
Date: Wed, 16 Dec 92 05:38:40 GMT

In article 2405@trl.oz.au, lampard@titan.trl.OZ.AU (Greg Lampard) writes:
> mark@alsvid.nr.une.edu.au (Mark Garrett Internet: mark@arvak.une.edu.au Phone: +61 66 20 3859) writes:
> 
> >From article <1992Nov30.215429.29379@sics.se>, by craig@sics.se (Craig Partridge):
> >>>From: peterd@pjd.dev.cdx.mot.com (Peter Desnoyers)
> >>> Secondly, people I've
> >>> talked to who work with WDM believe that ATM is fundamentally
> >>> incompatible with the more promising WDM switching mechanisms, due to
> 
> >> Taking an even wilder viewpoint, there's paper by Cisneros and Bracket in
> >> the October '91 JSAC (pp. 1348-1360) on how to build an ATM switch
> >> using a WDM switching fabric.
> 
> >	I've come across ATM, but what is WDM? What are the specs for WDM?
> >from the jist of the posting I guess WDM is some form of fast packer switching
> >with  "Wider" packs ???
> 
> >	Mark 
> >-- 
> >Mark Garrett	Internet:  mark@arvak.une.edu.au	Phone: 	+61 66 20 3859
> >   University of New England, Northern Rivers, Lismore NSW Australia.
> 
> From the limited information above, I'd say that WDM refers to
> optical wavelength division multiplexing.  That is, using different
> wavelengths of light over optical fibre to provide medium access to
> multiple users.  It's analogous to the way radio spectrum is currently
> used, and obviously is confined to all-optical networks.
> 
> Greg.

This is true: WDM = Wavelength Division Multiplexing. But I'm not sure
why "ATM is fundamentally incompatible with the more promising WDM
switching mechanisms". WDM is an OSI layer 1 (physical layer)
multiplexing mechanism whereas ATM is at layer 2. WDM (I thought) is
used merely to mux multiple channels (bit streams) onto one optic
fibre. The channels themselves may/mayn't have undergone ATM
multiplexing; there should be no dependency.

____________________________________________________________________________
Nathan Clarke.				Australian Telecommunications
					Research Laboratory (ATRI)    .-_|\
telephone:  61 9 351 3265		Curtin Uni of Technology     /     \
facsimile:  61 9 351 3244		Bentley WA, 3265.	     P_.-._/
e-mail:     clarke@atri.curtin.edu.au	Australia		          o
____________________________________________________________________________

Newsgroups: comp.dcom.cell-relay
From: myoung@force.ssd.lmsc.lockheed.com
Subject: Re: Implications for IBM
Reply-To: myoung@force.ssd.lmsc.lockheed.com
Organization: LMSC, Sunnyvale, California
Date: Wed, 16 Dec 92 23:54:22 GMT

In article <1992Dec16.173515.17042@NOC.Vitalink.COM>, dgr@RODIN (Daniel Robinson) writes:
>In article <BzAAwL.CGy@unix.portal.com> kyma@shell.portal.com (Matt J Young) writes:
>+
>+  The new opportunity is for an OS/2 market on the desktop, while
>+the  demand for risc in the data center begs for a simple, single
>+tasking kernel.
>
>I don't understand this distinction of single and multi-tasking.

  Just after posting, IBM announced their intention to license
the micro-kernel for server applications which require application
specific, proprietary operating systems. 

  Now IBM, please add to that the semantic control layer, a 
protocol layer which allows the arbitrary distribution of data across
arbitrary processors.

>Of course there will be multi-tasking on the desktop;

  Not according to 60 million DOS users.  Most of them have no background
tasks to perform, and satisfied with task switching at best.

>One should not infer a file system on the desktop.
  Explain this, teach me something.  You have some ideas here which are
smarter than my thinking on the subject.

> The data center needs a multi-tasking operating system to maintain 
>multiple contexts.

  I am refering to large clusters of low cost processors over which 
processes are spread, simultaneously existing in multiple processers 
at an instance.  In these cases, the individual hardware processers 
work just fine with a single task OS. (The message passing system
provides the multi-tasking affect.)  This is the model ffor enterprise
data bases.

>
>The paradigm of peer machines on desktops being served by slaves
>in the back room unnecessarily burdens the network...

  Well, the posters on this group tell me that 100 Mbps up to 1 Gbps
will be cheaper than a pair of Sharks (local hockey club) tickets.
Newsgroups: comp.dcom.cell-relay
From: hellstro@tnclus.tele.nokia.fi
Subject: Re: ATM & SONET
Organization: Nokia Telecommunications.
Date: Thu, 17 Dec 1992 09:18:04 GMT

In article ag@fokus.gmd.de (A. Gavras) writes:

> I know of the G.707 G.708 G.709 that describe the SDH Level-1, -4, -16 which
> is pretty much the same as SONET OC-3, OC-12, OC-48.
> I also know of the CCITT called cell based interface described in I.432.

Actually I.432 is in accordance with SONET/SDH specifications for ATM
transport. It doesn't matter wrether the PHY layer interface is cell based
or SDH based. The interface only has to fulfil the PHY medium characteristics
(G.703 for electrical or G.652 for single mode fibres) and the gross bit
rates 155.52Mbit/s or 622.08Mbit/s. The transfer capability requirements for
ATM cell transport are 149.76Mbit/s at 155.52Mbit/s PHY interface and
599.04Mbit/s at 622.08Mbit/s PHY interface. As an example of cell based
interfaces there is the Physical Layer Interface for 155.52 Mbit/s Multimode
Fiber Interface defined by the ATM Forum UNI specs.

>>>> Cell based = no external frame in addition to the ATM cells is needed
     to control the PHY layer transmission.

Anyway, I hope it will be as pure and direct as possible.

-Jan 
Newsgroups: comp.dcom.cell-relay
From: lampard@titan.trl.OZ.AU (Greg Lampard)
Subject: Re: WDM and ATM
Organization: Telecom Research Labs, Melbourne, Australia
Date: Wed, 16 Dec 1992 23:05:31 GMT

clarke@atri.curtin.edu.au (Nathan Clarke) writes:

>In article 2405@trl.oz.au, lampard@titan.trl.OZ.AU (Greg Lampard) writes:
>> mark@alsvid.nr.une.edu.au (Mark Garrett Internet: mark@arvak.une.edu.au Phone: +61 66 20 3859) writes:
>> 
>> >From article <1992Nov30.215429.29379@sics.se>, by craig@sics.se (Craig Partridge):
>> >>>From: peterd@pjd.dev.cdx.mot.com (Peter Desnoyers)
>> >>> Secondly, people I've
>> >>> talked to who work with WDM believe that ATM is fundamentally
>> >>> incompatible with the more promising WDM switching mechanisms, due to
>> 
>> >	I've come across ATM, but what is WDM? What are the specs for WDM?
>> >from the jist of the posting I guess WDM is some form of fast packer switching
>> >with  "Wider" packs ???
>> 
>> >	Mark 
>> 
>> From the limited information above, I'd say that WDM refers to
>> optical wavelength division multiplexing.  That is, using different
>> wavelengths of light over optical fibre to provide medium access to
>> multiple users.  It's analogous to the way radio spectrum is currently
>> used, and obviously is confined to all-optical networks.
>> 
>> Greg.

>This is true: WDM = Wavelength Division Multiplexing. But I'm not sure
>why "ATM is fundamentally incompatible with the more promising WDM
>switching mechanisms". WDM is an OSI layer 1 (physical layer)
>multiplexing mechanism whereas ATM is at layer 2. WDM (I thought) is
>used merely to mux multiple channels (bit streams) onto one optic
>fibre. The channels themselves may/mayn't have undergone ATM
>multiplexing; there should be no dependency.

>Nathan Clarke.				Australian Telecommunications
>					Research Laboratory (ATRI)    .-_|\

I think the incompatibility being referred to is that a "WDM switching
mechanism" uses the wavelength of light being transmitted to route information
through the network, as opposed to ATM which uses headers.  That is, in
principal in an all optical network you don't have to have switches
reading header information, they just have to be configured so that
light of a given wavelength gets passed to the appropriate output.  Such
a switch is transparent to the data being transmitted, so it will work
with any protocol and data rate.  So, for example,
you can send ATM cells over a WDM network, but the WDM switches wouldn't use
the cell-headers for routing, you'd need another signalling system for
that.

That being said, there are a lot of problems to be overcome before networks 
of this type will be a commercial proposition.  The most serious one
being that optical components, particularly wavelength-tunable ones, are
not cheap.

Greg.
Newsgroups: comp.dcom.cell-relay
From: dgr@RODIN (Daniel Robinson)
Subject: Re: Implications for IBM
Organization: Vitalink Communications, Fremont, California
Date: Thu, 17 Dec 1992 17:09:08 GMT

In article <1992Dec16.235422.7530@iscnvx.lmsc.lockheed.com> myoung@force.ssd.lmsc.lockheed.com writes:
+In article <1992Dec16.173515.17042@NOC.Vitalink.COM>, dgr@RODIN (Daniel Robinson) writes:
+>Of course there will be multi-tasking on the desktop;
+
+  Not according to 60 million DOS users.  Most of them have no background
+tasks to perform, and satisfied with task switching at best.
                       ^^^^^^^^^

Not according to user interface designers.  In my experience, when I explain
to a DOS user how UNIX works, and how workstations work, they express a strong
desire to have the same thing on their machines.

+>One should not infer a file system on the desktop.
+  Explain this, teach me something.  You have some ideas here which are
+smarter than my thinking on the subject.

The SNA network has an explicit hierarchy.  The user generated events are
processed by a series of communications processors until a definite request
is presented to the mainframe in a very tightly controlled format.
This paradigm works for a desktop window server running X.12 (or any
suitable followon to X.11) which does presentation services for shared
applications running on tightly coupled client machines.

We have desktop filesystems only because PC machines offered WYSIWYG
applications (very desireable) and the large computer vendors didn't
understand that at the time.  Most users in the business arena would rather not
be bothered by maintaining a disk based operating system on the desktop.
What users really want are not computers, but rather applications that work easily.

+>The paradigm of peer machines on desktops being served by slaves
+>in the back room unnecessarily burdens the network...
+
+  Well, the posters on this group tell me that 100 Mbps up to 1 Gbps
+will be cheaper than a pair of Sharks (local hockey club) tickets.

When this happens, DOS will be used only in certain Third World
countries...   {:>)

Dan Robinson
Newsgroups: comp.dcom.cell-relay
From: myoung@force.ssd.lmsc.lockheed.com
Subject: Multi-cast
Reply-To: myoung@force.ssd.lmsc.lockheed.com
Organization: LMSC, Sunnyvale, California
Date: Mon, 14 Dec 92 19:21:37 GMT

SUN has sponsored a research project on performing multi-cast
over the cell relay network(Wei, Liaw,Estrin,Romanow).  I picked 
up a copy of the article from an XTP conference.

The conclusion of the research was that embedded re-sequencers
within the cell relay network, operating at the cell level only,
would be able to operate a multi-casting logical network without
depletion of ATM cell headers, (using them for source and destination).
The idea is to collect a PDU at a local re-sequencer, then forward
the PDU to remote re-sequencers with intermixing of cell from
different sources.

This is an instance of the idea that application specific routers exist 
within the cell relay network.  The same principle can apply to transaction
systems, distributed data base, work flow, and workaday network
layer routers.

Two embedded router mechanisms exist: 1) Use the powerful out of band 
resource management layer to perform discovery and configuration; and 
2) Use the management layer itself for routing: wrap the data within the 
messaging layer, and program the messaging layer to perform what ever 
delivery mechanism is implied.  The second is possible since the messaging
layer exists on every node by definition.
Newsgroups: comp.dcom.cell-relay
From: lampard@titan.trl.OZ.AU (Greg Lampard)
Subject: Re: WDM and ATM
Organization: Telecom Research Labs, Melbourne, Australia
Date: Mon, 14 Dec 1992 22:13:25 GMT

mark@alsvid.nr.une.edu.au (Mark Garrett Internet: mark@arvak.une.edu.au Phone: +61 66 20 3859) writes:

>From article <1992Nov30.215429.29379@sics.se>, by craig@sics.se (Craig Partridge):
>>>From: peterd@pjd.dev.cdx.mot.com (Peter Desnoyers)
>>> Secondly, people I've
>>> talked to who work with WDM believe that ATM is fundamentally
>>> incompatible with the more promising WDM switching mechanisms, due to

>> Taking an even wilder viewpoint, there's paper by Cisneros and Bracket in
>> the October '91 JSAC (pp. 1348-1360) on how to build an ATM switch
>> using a WDM switching fabric.

>	I've come across ATM, but what is WDM? What are the specs for WDM?
>from the jist of the posting I guess WDM is some form of fast packer switching
>with  "Wider" packs ???

>	Mark 
>-- 
>Mark Garrett	Internet:  mark@arvak.une.edu.au	Phone: 	+61 66 20 3859
>   University of New England, Northern Rivers, Lismore NSW Australia.

From the limited information above, I'd say that WDM refers to
optical wavelength division multiplexing.  That is, using different
wavelengths of light over optical fibre to provide medium access to
multiple users.  It's analogous to the way radio spectrum is currently
used, and obviously is confined to all-optical networks.

Greg.
From: vjs@rhyolite.wpd.sgi.com (Vernon Schryver)
Newsgroups: comp.dcom.cell-relay
Subject: Re: LAN link cost issues
Date: 21 Dec 92 05:36:03 GMT
Organization: Silicon Graphics, Inc.  Mountain View, CA

In article <23095@venera.isi.edu>, finn@isi.edu (Greg Finn) writes:
> In article <to6efqs@sgi.sgi.com> rpw3@rigden.wpd.sgi.com (Rob Warnock) writes:
> 
> >30 meters is too short. The generally-accepted "desk to wiring-closet"
> >requirement is 100 meters, and even that is marginal.
> 
> 	Not really.  100 meters is an encompassing requirement.  30
> meters gets you a sizable percentage of point-to-point link distances
> in practice.  In our office tower it would handle most workstation to
> concentrator links now....

You have an unusual office tower.
100 meters is, as Rob says, short in many, and probably most situations.

Even 30m or 100 feet didn't mean that your wire closet must be about 30
feet from all of the desktops it serves (by the time you go down, up,
around, etc), the 10BaseT people as well as some big standards (JEDEC?
CCCITT? I forget) have written "100 Meters to the first wiring closet"
in stone that is read by customers, building designers, and so on.

> is several hundreds of dollars less ... you would choose that, no?

In real life, the medium between the desktop and the closet, whether
copper or 100Mbit/sec glass, is free.  What costs is pulling it and
putting connectors on the end.  This perhaps surprising fact is evident
if you install many campus sytems, or just watch the Interop Circus.


> There remains the ability to site additional concentrators also.  The
> desirability would depend upon the cost savings.  Four sites per floor
> is sufficient for complete geographic spread in a good sized
> multi-hall office building. ...

Wiring closest are very precious things.  You don't find extra ones.
You sometimes find extra rooms, but they'll have nice things like
transformers running at 140 degrees F and no ventilation.  (I've seen
more than one such in real life.)  All of the concentrators I heard
about or seen are as fragile as many workstations, as intolerant of
heat, quite demanding of power, and demanding of human attention.

You're not going to be able to hide concentrators in false ceilings,
even if the fire marshalls should not have fits.  For one thing, many
people who buy them have LED fetishes, and need to show thei pretty
lights on their $10,000 boxes to their bosses.



Vernon Schryver,  vjs@sgi.com
Newsgroups: comp.dcom.cell-relay
From: clarke@atri.curtin.edu.au (Nathan Clarke)
Subject: Re: WDM and ATM
Reply-To: clarke@atri.curtin.edu.au
Organization: Australian Telecommunication Research Institute
Date: Fri, 18 Dec 92 04:01:00 GMT

In article 27476@trl.oz.au, lampard@titan.trl.OZ.AU (Greg Lampard) writes:
> I think the incompatibility being referred to is that a "WDM switching
> mechanism" uses the wavelength of light being transmitted to route information
> through the network, as opposed to ATM which uses headers.  That is, in
> principal in an all optical network you don't have to have switches
> reading header information, they just have to be configured so that
> light of a given wavelength gets passed to the appropriate output.  Such
> a switch is transparent to the data being transmitted, so it will work
> with any protocol and data rate.  So, for example,
> you can send ATM cells over a WDM network, but the WDM switches wouldn't use
> the cell-headers for routing, you'd need another signalling system for
> that.

That's correct, in an all optical network, WDM is used to route the data
to the appropriate output port. We could then use the all optical
network as a physical layer medium for an ATM switched network at layer
2. I don't see any "incompatibility".

	Nathan.