david@comp.lancs.ac.uk (David Coffield) (04/30/87)
Suppose some Sun-3s were linked via a Cheapernet and the Cheapernet was to be connected to an ordinary Ethernet, linking other Suns and Vaxes (so it's all TCP-IP based). What do we get in the way of a connector to link the Cheapernet to the Ethernet so it all looks like one net? Any suggestions on products, costs etc welcome. I know DEC make something to do this but am not sure whether it would suit us. Please reply by mail rather than post an article. Thanks. David Coffield. -- janet: david@uk.ac.lancs.comp Department of Computing arpa: david@comp.lancs.ac.uk University of Lancaster uucp: ...!mcvax!ukc!dcl-cs!david Bailrigg, Lancaster, LA1 4YR, UK
robinson@ecsvax.UUCP (Gerard Robinson) (05/05/87)
In article <351@dcl-csvax.comp.lancs.ac.uk> david@comp.lancs.ac.uk (David Coffield) writes: >Suppose some Sun-3s were linked via a Cheapernet and the Cheapernet >was to be connected to an ordinary Ethernet, linking other Suns and >Vaxes (so it's all TCP-IP based). What do we get in the way of a connector >to link the Cheapernet to the Ethernet so it all looks like one net? The only official way of doing this (that I know of) is to use a repeater of some sort. One can purchase a thick-wire transceiver, a thin-wire transceiver and a standard segment-to-segment ethernet repeater, and accomplish this end. Total cost (depending on your discounts and lengths of transceiver cables) would be ~$1,750. A slightly more expensive, but more flexible solution, is provided by DEC, Cabletron, and perhaps others in the form of a MULTIPORT repeater (re: attribution below). This unit acts as a repeater, but allows up to eight thin-wire segments to be attached to a thick-wire one, with each segment electically terminated in the box itself. >Any suggestions on products, costs etc welcome. I know DEC make something >to do this but am not sure whether it would suit us. Gerard Robinson UNC School of Medicine
notes@hpcea.UUCP (05/06/87)
HP also makes a multiport repeater. We've ben successfully manufacturing it and shipping it since last fall. The HP 28645A ThinLAN Hub. It has one transcriver interface and four Cheapernet taps, so it exactly matches your needs. The Cheapernet taps are true taps (without terminators) and can go in the middle of a cable. Also, HP claims it has half the delay of a normal repeater. We use lots of these internally and really like them. Sorry to be so commercial here, but I think we've got a better product, and it is *never* mentioned. Walter Underwood Corporate Engineering
olds@3comvax.UUCP (05/12/87)
What's wrong with using a BNC->N series adapter? It just screws onto the
thick cable, and has a BNC connector on the other side. We use these here
when we have to use thick cable or N-Series tranceivers, and have had no
problems. The only restriction is that the inequality (3.28 * T) + E < 500
must hold (T=thick cable length in meters, E=thin cable length in meters).
I have no real idea what these cost, but I would think 20-50 USD would be
more than generous.
An all 3Com net can be twice as large (a statement of fact, no flames).
/cco
Chris Olds olds@3Com.COM (internet & domainified UUCP)
{sun,hplabs!oliveb}!3comvax!olds (old UUCP)merlin@hqda-ai.UUCP (David S. Hayes) (05/13/87)
In article <671@3comvax.3Com.COM>, olds@3Com.COM (Chris Olds) writes: > What's wrong with using a BNC->N series adapter? > I have no real idea what these cost, but I would think 20-50 USD would be > more than generous. At my local electronics supply house, $6.40 each. -- David S. Hayes, The Merlin of Avalon PhoneNet: (202) 694-6900 UUCP: *!seismo!sundc!hqda-ai!merlin ARPA: merlin%hqda-ai.uucp@brl.arpa
jerry@oliveb.UUCP (Jerry F Aguirre) (05/13/87)
In article <671@3comvax.3Com.COM> olds@3comvax.UUCP (Chris Olds) writes: >What's wrong with using a BNC->N series adapter? It just screws onto the >thick cable, and has a BNC connector on the other side. We use these here >when we have to use thick cable or N-Series tranceivers, and have had no >problems. The only restriction is that the inequality (3.28 * T) + E < 500 >must hold (T=thick cable length in meters, E=thin cable length in meters). ^^^^^^^ ^^^^^^ I am sure that you mean that T=THIN cable length and E=ETHERNET (regular thick cable) length. A thin ethernet segment is restricted to 185 meters max., thick is restricted to 500 meters.
coleman@sask.UUCP (Geoff Coleman @ College of Engineering) (05/13/87)
> > In article <351@dcl-csvax.comp.lancs.ac.uk> david@comp.lancs.ac.uk (David Coffield) writes: >>Suppose some Sun-3s were linked via a Cheapernet and the Cheapernet >>was to be connected to an ordinary Ethernet, linking other Suns and >>Vaxes (so it's all TCP-IP based). What do we get in the way of a connector >>to link the Cheapernet to the Ethernet so it all looks like one net? 3-COM sell a barrell connector to connect thin wire ethernet to thick wire. I can't remeber the part number off hand. Mind you we have had one back ordered for the better part of a year. I can't see why it's such a hard part to obtain. -- Geoff Coleman | BITNET: Coleman@sask College of Engineering | UUCP: {utcsri,ihnp4}!sask!skul!geoff University of Saskatchewan | Compserve: 76515,1513 just a number Saskatoon, Saskatchewan | voice: (306) 966-5415
olds@3comvax.UUCP (05/15/87)
As Jerry Aguirre (jerry@oliveb.UUCP) so gently states, I screwed up. In article <993@oliveb.UUCP> jerry@oliveb.UUCP (Jerry F Aguirre) writes: >In article <671@3comvax.3Com.COM> I write: ... >>The only restriction is that the inequality (3.28 * T) + E < 500 >>must hold (T=thick cable length in meters, E=thin cable length in meters). > ^^^^^^^ ^^^^^^ >I am sure that you mean that T=THIN cable length and E=ETHERNET (regular >thick cable) length. A thin ethernet segment is restricted to 185 >meters max., thick is restricted to 500 meters. T DOES mean THIN in the equation above - I misread the manual I copied the inequality from, and did not check what I wrote. Boy, is my face red! Chris Olds olds@3Com.COM or {sun,hplabs!oliveb}!3comvax!olds