jbn@glacier.STANFORD.EDU (John B. Nagle) (03/15/89)
All you need is a BNC to N cable adapter. This was all covered
about two months ago in this newsgroup.
Bear in mind the following:
1. When you do this, the entire cable becomes subject to thin
Ethernet length limitations. (This is an overly conservative
assumption, but unless you're comfortable using a time-domain
reflectometer on your Ethernet, it's a good rule to follow.)
2. The BNC T connector always goes on the back of the computer.
Don't insert any cable between the computer and the T connector.
If you do, the network may behave very strangely; some machines
won't be able to talk to some other machines.
3. Of course, if anyone disconnects a cable from the T connector,
the whole net goes down. You can disconnect the T from the
computer freely, but the cables must remain attached.
4. For small nets, a good rule to follow is to just hook the
thin Ethernet on the end of the thick one, using a BNC to N
adapter of the appropriate gender to replace the terminator.
Then, terminate the new thin Ethernet at its end with a thin
Ethernet terminator, or with a thick Ethernet terminator
and another BNC to N adapter.
5. The BNC to N adapter should be female-female, but these are hard
to find. If you have to get a female-male, you can add on a
standard "barrel" (a female-female BNC to BNC, or female-female
N connector) of the appropriate family. These are available from
Arrow, Newark, Hamilton/Avnet, etc.
John Naglejsloan@thor.UUCP (John Sloan) (03/17/89)
From article <18167@glacier.STANFORD.EDU>, by jbn@glacier.STANFORD.EDU (John B. Nagle): > 2. The BNC T connector always goes on the back of the computer. > Don't insert any cable between the computer and the T connector. > If you do, the network may behave very strangely; some machines > won't be able to talk to some other machines. > > 3. Of course, if anyone disconnects a cable from the T connector, > the whole net goes down. You can disconnect the T from the > computer freely, but the cables must remain attached. Thanks for the information, John. I hear rumors about a thinwire wall plate that has a special cable containing the equivalent of two thinwire coax cables, ending in the equivalent of a T-connector. It appears to be one cable with a thinwire coax connector on the end. When you plug one end into your workstation, and the other end into the wall plate, the wall plate automatically "splices" this thinwire extension into the network daisychain. When you unhook it from the wall it automatically completes the circuit, so that the network doesn't go down. Is there such a beast? John Sloan +1 513 259 1384 jsloan%spots.wright.edu@relay.cs.net Wright State University Research Center ...!uunet!ncrlnk!wright!jsloan 3171 Research Blvd., Kettering, OH 45420 ...!osu-cis!wright!jsloan Logical Disclaimer: belong(opinions,jsloan). belong(opinions,_):-!,fail.
stealth@caen.engin.umich.edu (Mike Peltier) (03/31/89)
> .... I hear rumors about a thinwire wall > plate that has a special cable containing the equivalent of two thinwire > coax cables, ending in the equivalent of a T-connector. It appears to > be one cable with a thinwire coax connector on the end. When you plug > one end into your workstation, and the other end into the wall plate, > the wall plate automatically "splices" this thinwire extension into > the network daisychain. When you unhook it from the wall it > automatically completes the circuit, so that the network doesn't go > down. > > Is there such a beast? > > John Sloan +1 513 259 1384 jsloan%spots.wright.edu@relay.cs.net > Wright State University Research Center ...!uunet!ncrlnk!wright!jsloan > 3171 Research Blvd., Kettering, OH 45420 ...!osu-cis!wright!jsloan > Logical Disclaimer: belong(opinions,jsloan). belong(opinions,_):-!,fail. Some of our Apollo workstations have such a connector for the coaxial network cable. Makes moving nodes around much less of a hassle, and the connectors aren't that hard to install. It's just a push and a twist, and your node is on the net. -Mike Peltier (I'll write a .signature one of these daqys...)
david@varian.UUCP (David Brown) (04/02/89)
In article <4256174a.1b7ec@odin.engin.umich.edu#, stealth@caen.engin.umich.edu (Mike Peltier) writes:
# .... I hear rumors about a thinwire wall
# plate that has a special cable containing the equivalent of two thinwire
# coax cables, ending in the equivalent of a T-connector. It appears to
# be one cable with a thinwire coax connector on the end. When you plug
# one end into your workstation, and the other end into the wall plate,
# the wall plate automatically "splices" this thinwire extension into
# the network daisychain. When you unhook it from the wall it
# automatically completes the circuit, so that the network doesn't go
# down.
#
# Is there such a beast?
Black Box has such a beast - they call it "FastTap". See p24 of the
latest (Spring 89) Black Box LAN Catalog. It's not cheap:
Barrel assembly $20
Wall plate $7.50
Cables: $90-$115 depending on length
--
David Brown 415-649-4000
Orion Network Systems 1995 University Ave. Suite 350 Berkeley CA 94704
{pacbell,lll-crg,zehntel,ista,rtech,csi,kinetics}!varian!david