Xref: utzoo comp.dcom.lans:1282 comp.sys.xerox:192 comp.sys.dec:642 Path: utzoo!mnetor!uunet!husc6!bloom-beacon!gatech!hubcap!ncrcae!ncrlnk!ncrwic!sfc!jbutala From: jbutala@sfc.Wichita.NCR.COM (John Butala) Newsgroups: comp.dcom.lans,comp.sys.xerox,comp.sys.dec Subject: Re: Need to connect Thin-Net to Fan-Out Unit Message-ID: <130@sfc.Wichita.NCR.COM> Date: 28 Apr 88 14:09:12 GMT References: <3288@ncrcae.Columbia.NCR.COM> Reply-To: jbutala@sfc.UUCP (John Butala) Organization: NCR Corporation, Wichita, Kansas Lines: 78 Keywords: thin-net thick-net fan-out 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 > 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 <{ncrlnk|ncrcae|ncr-sd}!ncrwic!j.butala}