rdn@chinet.chi.il.us (Richard Nichols) (07/14/89)
We have a need to connect two machines together that have thick-wire ETHERNET connections. Since there are only two machines in this 'network' I was wondering if there is such a thing as a 'null transceiver'? In other words, is there a way to connect our two machines without having to actually connect real transceivers? Any help would be appreciated. Rick Nichols rdn@chinet.chi.il.us
pst@anise.acc.com (Paul Traina) (07/14/89)
rdn@chinet.chi.il.us (Richard Nichols) writes: >We have a need to connect two machines together that have thick-wire >ETHERNET connections. Since there are only two machines in this 'network' I >was wondering if there is such a thing as a 'null transceiver'? Yes there is a way to do it, but it's a little more complex than just hacking a tranceiver cable to flip signals. When I was at ComDesign, we came up with just such a hack to connect two forms of stat. mux. that usually talked directly over the ethernet. First off, there are the expected wire switches in the tranceiver cable itself. Secondly, you must program the ethernet chips to operate in loopback (yes!) mode. I can't say that this will work for a Lance chip, but I have done it properly with a LCC. If you're able to hack the software that controls the ethernet chip, drop me a note and I'll try and dig up my old notes on how we got the bugger to work. On the other hand, if you can't do it a simple way, you could always purchase a DELNI (from Digital) or any other tap-expander, which will simply look like 8 ethernet tranceivers. You can hang a tap off the 9th jack and plug it into a real thick wire ethernet, or you can just flip a switch and have the DELNI look like the entire ethernet. If you'll only have those two machines, and you can't go in and mung them, I'm afraid your cheapest alternative is probably buying two tranceivers and a 2 meter ethernet segment. If you'll ever add on a third or fourth node, go with the DELNI-type device. Good luck & if anyone wants to know about mashing the cables and and reprogramming the ethernet chip, just drop me a line (I may be somewhat slow about getting back to you on it, as I may have to call some friends at ComDesign if I can't dig up my notes.) Paul -- "Calling people sexist because they are into S/M is like calling people capitalist because they like to play Monopoly(TM)." -- `Ask Aunt Sadie' / the Ministry of Truth
generous@dgis.daitc.mil (Curtis Generous) (07/14/89)
rdn@chinet.chi.il.us (Richard Nichols) writes: >We have a need to connect two machines together that have thick-wire >ETHERNET connections. Since there are only two machines in this 'network' I >was wondering if there is such a thing as a 'null transceiver'? In other > >Rick Nichols >rdn@chinet.chi.il.us The easiest way is to get a "Fan Out Unit" (aka multiport transceiver). Allows several (usually 8) devices to talk to one other without the need of a ethernet segment. No cheap, costs around $1000. --curtis --- Curtis C. Generous DTIC Special Projects Office (DTIC-SPO) ARPA: generous@daitc.mil UUCP: {uunet,vrdxhq,lll-tis}!daitc!generous
grim@udel.EDU (Dan Grim) (07/14/89)
rdn@chinet.chi.il.us (Richard Nichols) writes: >We have a need to connect two machines together that have thick-wire >ETHERNET connections. Since there are only two machines in this 'network' I >was wondering if there is such a thing as a 'null transceiver'? In other >words, is there a way to connect our two machines without having to actually >connect real transceivers? >Any help would be appreciated. >Rick Nichols >rdn@chinet.chi.il.us Black Box sells two-port and four-port transceivers that can do exactly what you want for somewhat less money than DELNI-like devices (8-port). Here's the info: NK-LE050A 2-port Ethernet Transceiver $450 NK-LE051A 2-port BNC Transceiver $450 NK-LE052A 4-port Ethernet Transceiver $699 NK-LE053A 4-port BNC Transceiver $699 Both units appear to use the standard AMP vampire or BNC tap and do not appear to require a separate transceiver for cable attachment. Both devices appear to be the same size which is approximately 3.5" x 7". Dan
afrlinkv@WPAFB-INFO5.AF.MIL (07/14/89)
Richard Nichols asked about a 'null transceiver' to connect two PCs without multiple transceivers and ethernet cable. So far all responses have recommended fanout boxes - an active device. There is an alternative; ANC, now a Division of Niravoice, Inc. makes the ANC-10. Their description follows: Ethernet AUI-AUI Direct Connection Device Direct connection of two Ethernet/IEEE 802.3 nodes up to 100 meters or 330 ft. without using transceivers and Ethernet coaxial cable. list price: $180.00 We've throughly tested this device and both sides fully meet the 802.3 specs for tranceivers. You can get about 30% off of list. ANC's address is: ANC Division of Niravoice, Inc. 103 East Alma Avenue San Jose, CA 95112 (408) 947-2040 FAX: (408) 947-1343 Good luck! Link Verstegen Integration Manager Network Solution, Inc. 4350 Will Rogers Parkway Suite 100 Oklahoma City, OK 73108 (405) 942-8884 AFRLINKV@WPAFB-info2.AF.MIL
Chucko@VERMITHRAX.SCH.SYMBOLICS.COM (Charles R. Fry) (07/14/89)
Date: 14 Jul 89 11:49:45 GMT
From: daitc!dgis.daitc.mil!generous@uunet.uu.net (Curtis Generous)
rdn@chinet.chi.il.us (Richard Nichols) writes:
>We have a need to connect two machines together that have thick-wire
>ETHERNET connections. Since there are only two machines in this 'network' I
>was wondering if there is such a thing as a 'null transceiver'? In other
>
>Rick Nichols
>rdn@chinet.chi.il.us
The easiest way is to get a "Fan Out Unit" (aka multiport transceiver).
Allows several (usually 8) devices to talk to one other without the
need of a ethernet segment. No cheap, costs around $1000.
--curtis
---
Curtis C. Generous
DTIC Special Projects Office (DTIC-SPO)
ARPA: generous@daitc.mil
UUCP: {uunet,vrdxhq,lll-tis}!daitc!generous
I have had excellent results with Cabletron's MT800, and the price and
delivery are right. They have offices in Silicon Valley and New Hampshire,
but I don't recall the phone numbers at the moment.
-- Chuck Fry
Chucko@Riverside.SCRC.Symbolics.COMrhott@RELAY.NSWC.NAVY.MIL (07/14/89)
>rdn@chinet.chi.il.us (Richard Nichols) writes: >>We have a need to connect two machines together that have thick-wire >>ETHERNET connections. Since there are only two machines in this 'network' I >>was wondering if there is such a thing as a 'null transceiver'? In other >> >>Rick Nichols >>rdn@chinet.chi.il.us > >The easiest way is to get a "Fan Out Unit" (aka multiport transceiver). >Allows several (usually 8) devices to talk to one other without the >need of a ethernet segment. No cheap, costs around $1000. > >--curtis >--- >Curtis C. Generous >DTIC Special Projects Office (DTIC-SPO) >ARPA: generous@daitc.mil >UUCP: {uunet,vrdxhq,lll-tis}!daitc!generous I have a copy of a "glossy" for a product from American Network Connections. It is for a device called "ANC-10". It is an Ethernet AUI-AUI Direct Connection Device. It basically connects two systems together. I wrote in the margin that the cost was ~$120.00 You might try contacting them: American Network Connections, Inc 462 Oakmead Parkway Sunnyvale, California 94086 Phone (408) 737 - 1511 One of their schematics looks something like this: Workstation -----aui cable------[ANC-10]------aui cable---- Workstation I have not tried this device, and I am not in any way affiliated with them. Hope that this helps! Bob Hott Networks Branch (Code E41) Naval Surface Warfare Center Dahlgren, VA 22448 (703) 663 - 7745
jnford@jay.weeg.uiowa.edu (Jay Ford) (07/15/89)
In article <8943@chinet.chi.il.us>, rdn@chinet.chi.il.us (Richard Nichols) writes: > > We have a need to connect two machines together that have thick-wire > ETHERNET connections. Since there are only two machines in this 'network' I > was wondering if there is such a thing as a 'null transceiver'? In other > words, is there a way to connect our two machines without having to actually > connect real transceivers? American Network Connections makes a thing called an "ANC-10 Ethernet AUI-AUI Direct Connection Device", which sounds like what you want. We have one here and it behaved very well (but has since been replaced by a multiport transceiver). It has LEDs and everything! We bought ours from a distributor: Illinois Computer Cable, Inc 5207 Walnut Ave Downers Grove, IL 60515 312-810-0200 1-800-323-2612 Jay Ford, Weeg Computing Center, University of Iowa, Iowa City, IA 52242 jnford@jay.weeg.uiowa.edu or jnfordpb@uiamvs.bitnet, 319-335-5555
rs@eddie.MIT.EDU (Robert E. Seastrom) (07/15/89)
In article <19719@louie.udel.EDU> grim@udel.EDU (Dan Grim) writes: >rdn@chinet.chi.il.us (Richard Nichols) writes: > >> <some stuff about hooking only a couple of machines together> >> <to form an Ethernet> > >Black Box sells two-port and four-port transceivers that can do exactly >what you want for somewhat less money than DELNI-like devices (8-port). >Here's the info: > > NK-LE050A 2-port Ethernet Transceiver $450 > NK-LE051A 2-port BNC Transceiver $450 > NK-LE052A 4-port Ethernet Transceiver $699 > NK-LE053A 4-port BNC Transceiver $699 > OK, so what's inside the box on one of these anyway? Judging from my previous experiences with Black Box, the fact that they sell them for $450 means you can probably whip one up for $100-$150. So, what makes one of these "ethernet-in-a-box"es work? Is it just a passive resistive network to keep the impedences looking OK to everyone? Or is it something active? (I must confess, I forget whether a DELNI has to plug into the wall, that would answer my question), but they warn you about coupling too many DELNIs together in the wrong configuration, which would suggest to me that the guts are not all that complicated. ---Rob
bzs@ENCORE.COM (Barry Shein) (07/16/89)
>On the other hand, if you can't do it a simple way, you could always >purchase a DELNI (from Digital) or any other tap-expander, which will >simply look like 8 ethernet tranceivers. You can hang a tap off the >9th jack and plug it into a real thick wire ethernet, or you can >just flip a switch and have the DELNI look like the entire ethernet. > >If you'll only have those two machines, and you can't go in and mung >them, I'm afraid your cheapest alternative is probably buying two >tranceivers and a 2 meter ethernet segment. If you'll ever add on >a third or fourth node, go with the DELNI-type device. Although DELNI type devices are always handy you can certainly hook these two together a lot cheaper by just building a small ethernet. You don't say if they're thick or thin net. If they're thin net you only need about $50 worth of parts to hook it all together, two terminators, two BNC T adaptors and a length of cable. If they're thick you'll need the transceivers which will cost more like $250 each plus terminators and cable (but still less than most DELNI type things which cost around $2K.) I still agree the DELNI is nicer if you can afford it. What I'm curious about in this regard is twisted pair stuff. I saw a thick-net to twisted pair (RJ11) adapter for $90. Is it possible to string two of these together back to back to make a simple net connection? A thin-net to RJ11 is about $35, could one of each be used to put a thick-net device into a thin-net? I guess I'm not up to speed at all on twisted-pair cabling so forgive any silliness. -Barry Shein Software Tool & Die, Purveyors to the Trade 1330 Beacon Street, Brookline, MA 02146, (617) 739-0202
eshop@saturn.ucsc.edu (Jim Warner) (07/16/89)
In article <12222@eddie.MIT.EDU> rs@eddie.MIT.EDU (Robert E. Seastrom) writes: >In article <19719@louie.udel.EDU> grim@udel.EDU (Dan Grim) writes: >>rdn@chinet.chi.il.us (Richard Nichols) writes: >> >>> <some stuff about hooking only a couple of machines together> >>> <to form an Ethernet> >> >>Black Box sells two-port and four-port transceivers that can do exactly >>what you want for somewhat less money than DELNI-like devices (8-port). >>Here's the info: >> >> NK-LE050A 2-port Ethernet Transceiver $450 >> NK-LE051A 2-port BNC Transceiver $450 > >OK, so what's inside the box on one of these anyway? Judging from >my previous experiences with Black Box, the fact that they sell them >for $450 means you can probably whip one up for $100-$150. =================== Black box is in the business of selling solutions to problems. Sure. If you know what you're doing you could make one of these for less money. There are active components inside the box. They are required because Ethernet interfaces expect to see an echo of their signal come back when they transmit. Logic inside the box has to decide which signal to gate through in _both_ directions. I don't know what other folks are paying for their thin net transceivers. We get ours for about $130 each. Add $14 for a pair of terminators and $5 for a short BNC cable. It comes out to be less expensive than the Black Box solution by about $170.
root@swituc.UUCP (Admin) (07/16/89)
In article <19719@louie.udel.EDU>, grim@udel.EDU (Dan Grim) writes: > rdn@chinet.chi.il.us (Richard Nichols) writes: > > Black Box sells two-port and four-port transceivers that can do exactly We use these when we want a very small network (2 to 4 machines) with no outside world connections, such as a "secure" development group. They work completely satisfactorily and can be used to tie into the larger Ethernet systems when desired.
waugh@dg-rtp.dg.com (Matthew Waugh) (07/27/89)
>rdn@chinet.chi.il.us (Richard Nichols) writes: >>We have a need to connect two machines together that have thick-wire >>ETHERNET connections. Since there are only two machines in this 'network' I >>was wondering if there is such a thing as a 'null transceiver'? In other >> >>Rick Nichols >>rdn@chinet.chi.il.us Allied Telesis makes a two port Transceiver named the CentreCOM 250. Two terminators and a couple of drop cables should see you in business. Off hand I don't have a price, but if anyone is interested drop me mail and I can find out from our last set of purchases. We have used them, and they do work (although we haven't used them as "null transceivers". Mat ------------------------------------------------------------------------ Matthew Waugh waugh@rtp.dg.com RTP Network Services {world}!mcnc!rti!dg-rtp!waugh Data General Corp. RTP, NC. (919)-248-6034