m-liu@eastend.columbia.edu (Micky Liu) (02/13/89)
I have a small thinwire ethernet that I would like to extend from one site to another. What I was envisioning was something like: =================[]------------------------------------[]================ ethernet twisted-pair ethernet I don't need to be able to use the signal on the twisted-pair, I just need to get the signal on both my ethernet segments, what I need to know is what type of devices the [] are... Are there such things and what are their capacities. Ideally the repeater will carry the entire bandwidth across as opposed to going from 10M/sec to 56K/sec... Am I dreaming? Secondly is there some method of calculating the amount of traffic that you need to support on your segments? We are running some intense database programs across the segments, what is the ideal bandwidth? Can I exist with the lower bandwidth? Thanx! Micky Liu arpa: micky@cunixc.cc.columbia.edu uucp: ...!rutgers!columbia!eastend!m-liu bitnet: malua@cuvmc
fosterm@ogccse.ogc.edu (Mark Foster) (02/13/89)
>I have a small thinwire ethernet that I would like to extend from one >site to another. What I was envisioning was something like: > > >==============[]-------------------------------[]================ >ethernet twisted-pair ethernet > > what I need to >know is what type of devices the [] are... Depends on the distance of the twisted pair (TP). If it's greater than about 100m, then you'll probably not make 10Mb (i.e. T1 or T3 is prob. about the best you could do). If it is in the 100-150m range, you could use an ether-over-TP product (e.g. Cabletron's MMAC): =======[MMAC]-----------[tp BALUN xcvr]=========== coax TP thin coax If you don't have to use TP, I'd go fiber, with a coax/fiber repeater: ======[c/f rep.]~~~~~~~~~~~[c/f rep.]========== If you're stuck with TP and beyond the ether over TP range, then the solution is a fair more expensive and hard to make fast. We use a Proteon P4200 router (which may be overkill for your situation, but would help traffic/bandwidth limits of 56K, T1, T3 type service). We currently run 56K over the TP link: ======[P4200]--------------[P4200]============ ---- Mark Foster CSE Systems Support Oregon Graduate Center fosterm@cse.ogc.edu
goodloe@ingr.com (Tony Goodloe) (02/13/89)
In article <6162@columbia.edu>, m-liu@eastend.columbia.edu (Micky Liu) writes: > I have a small thinwire ethernet that I would like to extend from one > site to another. What I was envisioning was something like: > > > =================[]------------------------------------[]================ > ethernet twisted-pair ethernet > the [] are baluns, and are avaible all over the place. 3Com makes some and markets them under the name Pair Tamers. I have not used them, but we will be getting some shortly. They (baluns) sound like just what you are looking for. Tony Goodloe ...uunet!ingr!goodloe
smb@ulysses.homer.nj.att.com (Steven M. Bellovin) (02/13/89)
In article <6162@columbia.edu>, m-liu@eastend.columbia.edu (Micky Liu) writes: > I have a small thinwire ethernet that I would like to extend from one > site to another. What I was envisioning was something like: > > > =================[]------------------------------------[]================ > ethernet twisted-pair ethernet > > Are there such things and what are their capacities. > > Ideally the repeater will carry the entire bandwidth across as opposed > to going from 10M/sec to 56K/sec... The key question is how far you're trying to go on twisted pair. If it's not too far (and I don't know the limit), you can use AT&T's STARLAN 10, or other similar products from other companies. STARLAN 10 *is* Ethernet, except over twisted pair instead of coax. And repeaters are made that go from twisted pair to coax. *But* there is a distance limit that is almost certainly less than 500 meters, though how much less I don't know. And this assumes pure twisted pair; not something going through a phone company switch somewhere.