[comp.sys.mac.comm] ethernet over twisted pair

JAYMS@CUNYVM (12/28/90)

Anyone have any experience or info about ethernet cards over twisted
pair connections. I'd like to use pre-wired telephone cabling and have
the convenience of Phonenet connectors - or close. What's this I hear
about a new ethernet hardware/standard from Apple?

I'd like to avoid running separate cable for thin BNC style ethernet.
Any info would be appreciated. Please reply directly to me. Thanks!

toad@athena.mit.edu (John P. Jackson) (12/30/90)

In article <90361.180653JAYMS@CUNYVM.BITNET> JAYMS@CUNYVM writes:
>Anyone have any experience or info about ethernet cards over twisted
>pair connections. I'd like to use pre-wired telephone cabling and have
>the convenience of Phonenet connectors - or close. What's this I hear
>about a new ethernet hardware/standard from Apple?
>
>I'd like to avoid running separate cable for thin BNC style ethernet.
>Any info would be appreciated. Please reply directly to me. Thanks!

Well, I installed a LattisNet network, which is made by Western Digital.
LattisNet is a pre-10 Base T ethernet protocol.  I found that it just wouldn't
stay up for more than an hour or two when I had it connected through telephone
wiring that was already supporting a phone system in the same cable.  I had
to run it on phone cable that was subsequently installed soley for the 
purpose of the network.  Racal Interlan in Boxborough, MA is now making
UTP (Unshielded Twisted Pair, ie., most phone system cable these days) ethernet
interface cards for the Macintosh.  I know they are not the only ones, also.

JJ

JS05STAF@MIAMIU.BITNET (Joe Simpson) (01/01/91)

We have Latissnet running 10baseT ethernet in the same bundle as both
POTS(plain old telephone service) and Digital telephone service.

jdishaw@cbrown.claremont.edu (Pom Ac Comp Staff) (01/01/91)

In article <1990Dec30.092629.10471@athena.mit.edu>, toad@athena.mit.edu (John P. Jackson) writes...
> 
>Well, I installed a LattisNet network, which is made by Western Digital.
>LattisNet is a pre-10 Base T ethernet protocol.  I found that it just wouldn't
>stay up for more than an hour or two when I had it connected through telephone
>wiring that was already supporting a phone system in the same cable.  I had
>to run it on phone cable that was subsequently installed soley for the 
>purpose of the network.  Racal Interlan in Boxborough, MA is now making
>UTP (Unshielded Twisted Pair, ie., most phone system cable these days) ethernet
>interface cards for the Macintosh.  I know they are not the only ones, also.
> 
>JJ
From what I have been told (by Cabletron) is that a 10 Base-T compliant
product can go over the same cable with the phone.  Note, however, that
10 Base-T does not use a USOC jack, but rather the "new" AT&T jack (RJ445
I believe).  I haven't seen 10 Base-T used on the same cable as the phone,
but from what I can see from the pin-out and the pair matching, it should
work.  I don't want to waste bandwidth with any technical information, so
if anybody is interested send E-Mail to me.

James R. Dishaw
JDISHAW@CBROWN.CLAREMONT.EDU

dce@smsc.sony.com (David Elliott) (01/02/91)

In article <10261@jarthur.Claremont.EDU> jdishaw@cbrown.claremont.edu writes:
>From what I have been told (by Cabletron) is that a 10 Base-T compliant
>product can go over the same cable with the phone.  Note, however, that
>10 Base-T does not use a USOC jack, but rather the "new" AT&T jack (RJ445
>I believe).

This is true.  Our office has used such a system for over a year, and
it has been very reliable.

The one thing to realize is that 10BaseT is like thick ethernet in
terms of adding new connections.  Unlike thin ethernet, where a
T-connector can be used to add a device connection, and PhoneNet
(which, of course, isn't ethernet), where the connector has a builtin
splitter, 10BaseT requires that each controller connection connect to
one ethernet device.

I haven't heard of a 10BaseT multi-tap (or "DELNI", for those of you
with DEC tendencies), though I suspect they do or will exist.  You can
certainly convert 10BaseT to thick ethernet and use a DELNI, or go
straight to thin ethernet and take advantage of that connection style.

My opinion is that the right way to go in most cases is to use 10BaseT
as the connection between the work areas and the central patching
station, and to convert to thin ethernet in the office, and convert to
thick ethernet only when needed.

In the past 15 months, I've had from 1 to 4 machines in my office at
any given time, with various combinations of thick and thin ethernet
connectors.  With just a couple of twisted pair jacks in the office, I
would have had to go through contortions every time I wanted to add a
machine.  But, by converting to thin ethernet, I can easily add and
remove machines as I get them.  In fact, I share my single 10BaseT
connection with another person, and even though we have had as many as
10 machines on our thin ethernet, it's never been a performance problem
(and we're both network hogs).

nolan@helios.unl.edu (Michael Nolan) (01/02/91)

When I was looking for a 10BASE-T concentrator, I was talking to a rep from
Cabletron.  He said that Cabletron makes a device that goes on a 10BASE-T
line and converts it to thinnet.  (He implied that it handles 4 stations.)
Since I don't have the specs in front of me, I'm really not sure exactly
what the difference is between that and a 10Base-T to thinnet converter.

rpcfod@uarthur.UUCP (Robert Patt-Corner) (01/02/91)

In article <1990Dec30.092629.10471@athena.mit.edu>, toad@athena.mit.edu (John P. Jackson) writes:
> In article <90361.180653JAYMS@CUNYVM.BITNET> JAYMS@CUNYVM writes:
> 
> Well, I installed a LattisNet network, which is made by Western Digital.
> LattisNet is a pre-10 Base T ethernet protocol.  I found that it just wouldn't
> stay up for more than an hour or two when I had it connected through telephone
> wiring that was already supporting a phone system in the same cable.  
> 

We had rather better luck with Synoptics 10BaseT (1000 system - couldn't
sprint for the fancier 3000 with net management).  Nearly all our
existing lines worked out OK.  Have tested two cards - (Whomever)'s
EtherPort II with Synoptics 508 Transceiver works fine (Kinetics to Excelan
to Novell to ... is it Dayna now?).  We've just bought the Dayna cards
with 10BaseT option, and the cards seem fine, the drivers don't -
hang when accessing LANWorks (Whoops - Pathworks).  But the Excelan
drivers work with the Dayna cards.

rpcfod@uarthur.UUCP (Robert Patt-Corner) (01/02/91)

We use Digital's DESPR (Single-port repeater) to go from 10BT to thinnet
without problem.  Any old thin-net repeater designed to run thin spurs off
a thick backbone should do.  Just use a 10BaseT transceiver to go from the
10BT connection to the AUI of the repeater.  This works well for setting 
up classrooms off one tap, etc.

norm@hydro.wbst845e.xerox.com (Norm Crowfoot) (01/05/91)

The other thing that's really neat about having 10BT wiring is that one can
patch up arbitray AppleTalk connections whenever one wants.  With our new
SynOptics panels, we're having a riot of a time putting in all sorts of
arbitray circuits besides ethernet--which is why we bought the wiring plant.
--
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