rbthomas@caip.UUCP (03/12/87)
Does anybody out there have any experience with thin ethernet? What happens to the network if somebody unhooks their machine from the BNC connector and leaves it flapping in the breeze? Assuming that nothing bad happens, then what happens after it has flapped for a couple of months and finally comes in contact with a lurking paperclip just waiting to short the cable? Has this ever happened to you? I have nightmares on the subject, and have been holding off putting in a thin ethernet in our building because of them. Reply by mail, or post to the net, or phone me (only if you have *real* experience with thin ethernet to relate). I will summarize if interest warents. Rick Thomas rbthomas@caip.rutgers.edu (ARPAnet) seismo!rutgers!caip!rbthomas (UUCP) (201) 932-4301
normt@ihlpa.UUCP (03/13/87)
In article <4122@caip.RUTGERS.EDU>, rbthomas@caip.RUTGERS.EDU (Rick Thomas) writes: > Does anybody out there have any experience with thin ethernet? > What happens to the network if somebody unhooks their machine from the > BNC connector and leaves it flapping in the breeze? > Assuming that nothing bad happens, then what happens after it has flapped > for a couple of months and finally comes in contact with a lurking > paperclip just waiting to short the cable? What happens is just what you think would happen. As long as the it is only the "T" connection that is undone (i.e. not the cable itself) there will be no problems. We have about 8-9 hanging empty on our cable at all times. And, of course, if something metal touchs and shorts out the BNC connector, the communication is dead. Some coax drivers will overheat on the rest of the cable and die. Others are robust enough you handle this for some time. For the most part, it is ok to let them dangle, but care should be taken not to short the BNC. Our network is not more than about 20 meters, so longer networks may have noise margin problems, but I doubt it. Norm Tiedemann ihnp4!ihlpa!normt AT&T Bell Labs Naperville, IL 60566
jjgv@gmv.es (Juan Jose Galan) (08/18/89)
I have been following Dave Hill, Frank Rahmani and Bob Kilgore
messages concerning wall connection possibilities for thin ethernet,
as the company I work for is building a new facility including thin
ethernet. None of the presented options seem to be quite nice from the
aesthetic point nor from the maintanability and fail safe use by a lot
of users (in my case, over 100, I have a multiport from Isolan, Vaxes,
Sunes, ATs, ...) I have found a wall plug from a German company called
Telega"rtner plus a 'drop' cable that seems to solve theproblem, but it
is really not low-cost:
the wall plug (ref. T46802200 or EAD, I believe) has a couple of female BNCs
where you plug the thin ethernet, and in the front has two 'propietary-type'
plugs, where you can connect a 'propietary-type' cable (to each one), and
this cable can be connected to the ethernet board on your AT without the
BNC-T (cable ref. EDA).
Principal advantages are:
you can plug or unplug this special cable ethier from your PC or from
the wall outlet without disturbing the net (!?)
you have a nice wall connector and a single nice cable without reducing
your node count
you have a couple of ethernet nodes at hand with only one wall
outlet maintenance is lowered
no closing the net cables are required when nothing is plugged cables
are available in 2, 2.5, 3 and 5 meters lenth
you can even mount power supply in the same wall outlet (interesting
in case of protected supply)
all those advantages are claimed by the vendors, I have no more information
than that. Amongst disadvantages, I know by the moment but one: price! Wall
outlet is around 7500ptas (or 120DM aprox); cable is around 8000 to
10000ptas (or 127 to 160DM).
I have a couple of questions:
1.- Has somebody used this or knows of someone that has? What can be
said about advantages and disadvantages?
2.- Can someone provide me some more hints on the subminiature MAUs (trans-
ceivers) such as aprox cost, limitations, number of them per segment,
are they active (I suppose yes), is it possible to connect them to the
normal ATs ethernet cards (via BNC?) like 3Com ones (I suppose not), ...
As I am not usually following the news, I would appreciate if apart from
the usual news answers a direct e-mail message to me could be sent. My
address is
cbachmaier@gmv.es (Carlos Bachmaier), or you can also try:
within Europe: cbachmaier%gmv.es@mcvax.uucp
or mcvax!gmv.es!cbachmaier
within USA: mcvax!gmv.es!cbachmaier@uunet.uu.net
or uunet!mcvax!gmv.es!cbachmaier
Carlos Bachmaier
GMV, Cristobal Bordiu 35, E-28003, Madrid, Spain
Disclaimer: I have not shares on Telega"rtner not do I receive any fee for
this. Furthermore, the information hereto provided has been gathered from
comercial propaganda and interviews with vendors, so there could be
inaccuracies, misunderstandings, ...
Even more, as you can see from my message, I am not an expert myself on all
this matters, but the expert is on holidays and the building is going on ...
Deliverytime: 9th November!
In any case, I think this solution seems promising, althougt perhaps to
costly!
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