darrelj@sdcrdcf.UUCP (06/22/84)
Intel, DEC and TCL all sell boxes to replace up to 8 tranceivers by a single
tranceiver (or none if very local). The main problem with these boxes is
they cost very nearly as much per line as tranceivers (especially if you
don't use all 8 ports). I see their main value as fixing lack of planning
in providing cable space to tap enough tranceivers in one room, or to get
around the hundred stations per cable segment limit.
--
Darrel J. Van Buer, PhD
System Development Corp.
2500 Colorado Ave
Santa Monica, CA 90406
(213)820-4111 x5449
...{allegra,burdvax,cbosgd,hplabs,ihnp4,sdccsu3,trw-unix}!sdcrdcf!darrelj
VANBUER@USC-ECL.ARPAbcn@mit-eddie.UUCP (Clifford Neuman) (06/25/84)
The break even point for the Delni is about 4. If you are going
to hook up less than 4 systems, you might as well get the individual
trancievers. This break even point however does not take into
consideration the cost of spares. With individual trancievers,
if one breaks, the rest of the network still works, and usually
one spare tranciever is all that you really need around. With the
Delni, if it breaks, none of your machines will work. DEC sells
spares for the two major components in the Delni, but combined they
cost almost as much as the Delni itself.
There are other advantages to the Delni though. It has a switch on it
that allows you to isolate the Delni from the rest of the network if you
have it connected to a larger network. This is useful if something
happens to the rest of the network. You can simply isolate the
Delni, and the machines connected to it will once again be able to talk
to one another.
What I have said probably applies to other devices similar to the
Delni, but not having had experience with them, I have no way
of being sure. In all, I like the Delni. It is a lot nicer only
having to attach one tranciever to our ethernet cable than 5.
~ Cliff
{decvax!genrad,ihnp4}!mit-eddie!bcn
BCN@MIT-XX.ARPAsteveg@hammer.UUCP (Steve Glaser) (06/27/84)
Another big win with DELNI like boxes is that you don't need to have 2.5 meters of coax "frontage" to install a transciever (they are supposed to be on 2.5 meter intervals along the ethernet coax). Minimizing "wasted" cable helps when your network is close to max length (as are many of ours unless we bought some repeaters). Besides, what do you do with all the exceee cable? It doesn't bend easily so it's kinda hard to hide. We also had troubles with some folks transcievers not talking to some folks ethernet chip sets. The newer transcievers usually don't have the problem, but putting a DELNI in there made it go away for those that did (DEC version - I don't know about other vendor's equivalents). Steve Glaser tektronix!steveg steveg.tektronix@csnet-relay