[comp.sys.dec] Need to connect Thin-Net to Fan-Out Unit

ralph@ncrcae.Columbia.NCR.COM (Ralph Hightower) (04/27/88)

I need a way to connect a thin-net lan to a fan-out box.  We have two
different lans within Quality Assurance, a production lan and a test lan.
Each lan within the QA lab has a fan-out unit (Cabletron MT-800) connected
to a transceiver (BICC 1112-X) on the thick ethernet cable.  The thin-net
lan is currently connected to the end of the thick ethernet cable on the
test lan.

Most NCR TOWER's that need to be switched between the test lan and the
production lan are attached to the fan-out box so we can switch to the
other fan-out box when we need to perform testing or production items.

Is there any equipment that will allow me to attach a thin-net lan to the
fanout unit, so I can switch between the production net and the test net
easily?

To comp.sys.dec:
Will the DEMPR (ThinWire Ethernet Multiport Repeater) allow me to connect
the thin-net lan to the Cabletron MT-800 fanout box?  Is there anything
else that could solve my purpose?

To comp.sys.xerox:
I included you because Xerox is the originator of Ethernet.

I omitted comp.sys.intel because probably most discussion going on there is
the merit's of the '386 vs. '030 (although Intel is part of the Ethernet
trilogy).

Please edit the newsgroups file to comp.dcom.lans.  I visit that group more
often than comp.sys.xerox.or.dec.
-- 
            ralph@ncrcae.Columbia.NCR.COM   <Ralph M. Hightower>
            NCR Corp., Engineering & Manufacturing - Columbia, SC
                               Home of THE USC!
    South Carolina had a University 49 years before California was a state.

jbutala@sfc.Wichita.NCR.COM (John Butala) (04/28/88)

In article <3288@ncrcae.Columbia.NCR.COM> ralph@ncrcae.UUCP (Ralph Hightower) writes:
>I need a way to connect a thin-net lan to a fan-out box.  We have two
>different lans within Quality Assurance, a production lan and a test lan.
>Each lan within the QA lab has a fan-out unit (Cabletron MT-800) connected
>to a transceiver (BICC 1112-X) on the thick ethernet cable.  The thin-net
>lan is currently connected to the end of the thick ethernet cable on the
>test lan.
>
>Most NCR TOWER's that need to be switched between the test lan and the
>production lan are attached to the fan-out box so we can switch to the
>other fan-out box when we need to perform testing or production items.
>
>Is there any equipment that will allow me to attach a thin-net lan to the
>fanout unit, so I can switch between the production net and the test net
>easily?
>

An Ethernet repeater of any kind will allow you to connect thin Ethernet
cable into a Fan-out box.  In the case of ThinWire Ethernet Multiport
Repeater mentioned below, you do not need any additional hardware.  In
the case of a standard single port Ethernet repeater, you need an external
transceiver with a BNC tap to do what you want.  I might mention that many
companies make the ThinWire Ethernet Multiport Repeater: Cabletron MR9000-C,
BICC 1125-0, DEC DEMPR, and others.

In your case however, THIS WILL NOT WORK the way your two networks are set
up.  You are using an SQE transceiver to connect your Fan-out boxes to 
their respective networks, BUT MOST REPEATERS DO NOT LIKE SQE.  In fact,
hooking a repeater to an SQE tap can bring down your entire network; I know
because I have done it.  You have a few options to make it work the way
you were talking about:
	1) Buy Non-SQE transceivers to connect your Fan-out boxes to the
	   network.  This may foul up anything else that you want to connect
	   to the Fan-out that requires the SQE signal.
        2) Buy a couple Fan-outs which allow you to configure the individual
	   ports as non-SQE/SQE.  Micom makes a Fan-out unit called the 8-4-1.
	   My understanding is that you configure each group of four ports as
	   non-SQE or SQE.  In other words, this unit supports SQE and non-SQE
	   devices at the same time if you so desire.

Although I do not know your exact needs, I am going to make a suggestion.
Have you considered connecting your production LAN to your test LAN via
a segmentable repeater?  A segmentable repeater allows you to manually
filter packets going between the two LANs.  If we call your test LAN, LAN A;
and we call your production LAN, LAN B.  You have the option of the following:
	1) Allow all packets from LAN A to go to LAN B and visa versa.
	2) Only allow packets from LAN A to go to LAN B.
	3) Only allow packets from LAN B to go to LAN A.
	4) Do not allow any packets to go between LAN A and LAN B.
This is all done via switches and diagnostic lights on your repeater. You
do not have to disconnect any cables and move them somewhere else.

>To comp.sys.dec:
>Will the DEMPR (ThinWire Ethernet Multiport Repeater) allow me to connect
>the thin-net lan to the Cabletron MT-800 fanout box?  Is there anything
>else that could solve my purpose?
>
>To comp.sys.xerox:
>I included you because Xerox is the originator of Ethernet.
>
>I omitted comp.sys.intel because probably most discussion going on there is
>the merit's of the '386 vs. '030 (although Intel is part of the Ethernet
>trilogy).
>
>Please edit the newsgroups file to comp.dcom.lans.  I visit that group more
>often than comp.sys.xerox.or.dec.
>-- 
>            ralph@ncrcae.Columbia.NCR.COM   <Ralph M. Hightower>
>            NCR Corp., Engineering & Manufacturing - Columbia, SC
>                               Home of THE USC!
>    South Carolina had a University 49 years before California was a state.


-- 
---
John Butala           Automation Engineering, NCR E&M Wichita
                      <j.butala@Wichita.NCR.COM>
		      <{ncrlnk|ncrcae|ncr-sd}!ncrwic!j.butala}