Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!utgpu!water!watmath!clyde!rutgers!aramis.rutgers.edu!hobson From: hobson@aramis.rutgers.edu.UUCP Newsgroups: comp.os.vms Subject: Re: WANTED Inexpensive ethernet thinwire repeater. Message-ID: <1482@aramis.rutgers.edu> Date: Thu, 10-Sep-87 22:08:32 EDT Article-I.D.: aramis.1482 Posted: Thu Sep 10 22:08:32 1987 Date-Received: Sat, 12-Sep-87 15:20:25 EDT References: <1467@aramis.rutgers.edu> <667@cfa.cfa.harvard.EDU> Organization: Rutgers Univ., New Brunswick, N.J. Lines: 109 In article <667@cfa.cfa.harvard.EDU> wyatt@cfa.harvard.EDU (Bill Wyatt) writes: > in article <1467@aramis.rutgers.edu>, hobson@aramis.rutgers.edu (Kevin Hobson) says: > > > >> > >> I have a local area VAXCluster consisting of a '750 and a > >> uVAXII. I am intending to ad a VAXstation 2000 to this LAVC. > >> The '750 and uVAXII are both on a DELNI which is hooked to our > >> standard baseband (thickwire) ethernet. > >> > >> Who manufactures an inexpensive baseband to thinwire > >> repeater? Even names and addresses (phone numbers) of ethernet > >> hardware manufacturers would give me someplace to start. ..... > > MT-500-01 Transceiver with user selectable "heartbeat" (In other > > words, can be use as Ethernet Version 1, 2, or IEEE > > 802.3 transceiver) > > > > MT-500-03 Same as above with intrusive BNC-Series tap for use with > > Thin Ethernet Coaxial Cable (In other words, this > > device with MT-500-01 or local repeator (LR-2000) and > > transeiver cable should help you) > > These are `ST500-xx', not `MT'. The ST500-03 is the DESTA equivalent. > And, there's no `or' about it. You need the local repeater, an > ST500-01 or -02, and ST500-03 to do the above (see diagram below). > You'd have power and plug/receptacle mismatches otherwise. Yes, they are ST500, sorry. The 'or' I will explain below. > > > > LR-2000 Local Repeator (DEC DELNI-equivalent) > > No, this is the DEREP equivalent, at about 1.5k from Cabletron (I can't > remember the exact price, because we get a discount, and I don't remember > the list prices. The DELNI equivalent is the MT-800. > I getting my terminology mixed up, again. Thanks for the correction. > So, assuming the Ethernet topology restrictions aren't violated by the > new repeater: > > <===X===========================X=============> (trunk Ethernet cable) > | | > | (xceiver cable) | > | | > --------- ------------- > | DELNI | | repeater | > --------- ------------- > | | | > | | | > 750 uVax x---------X---------------T--------x (thinwire) > (ST500-03) ---------- > | VS2000 | > ---------- > Your topology works if you are going for the maximum specifications of both thin and thick ethernet (500 meters thick and 200 meters thin) If your network will never get any bigger <===X=======================================> (trunk Ethernet cable) | | (xceiver cable) | --------------------------- | DELNI | I use a MT-800, in loopback mode. --------------------------- | | | | | | | | |Female end of the DELNI | | Free male ends | 750 uVax | | x---------X---------------T--------x (thinwire) (ST500-03) ---------- | VS2000 | ---------- OR (I think this would have answer the question.) (trunk Ethernet cable) <===X===========================C--------------------T----------> (thin_net) | Thick_to_BNC connector ---------- | (xceiver cable) | VS2000 | | ---------- ---------- | DELNI | ---------- | | | | 750 uVax Both topologies assume you stay within thick and thin ethernet specifications. Either: A) 500 meters maximum for thick B) 200 meters maximum for thin C) Combination of the two: Total_length (500 meters max.)= (thin * 3) + thick We use a sun as a gateway between the thick to thin networks (Ex. thick___SUN____DELNI___ST500-03___thin ). -- - Kevin Hobson - ARPA: hobson@rutgers.edu - UUCP: {ames, seismo, harvard, ucla-cs, cbosgd, moss}!rutgers.edu!hobson - BITNET: hobson@cancer.bitnet - Rutgers University, New Brunswick, NJ 08903 (201) 932-2260 (201) 932-5027