perl@step.UUCP (Robert Perlberg) (06/14/90)
I once read in this newsgroup that one should not run thin Ethernet
cable between the workstation and the T-connector. I don't remember
what the reasoning was or what ill effects would come of it. We just
had some thin Ethernet cabling done and the electricians are trying to
convince us to allow them to run a line from the T-connector (under the
desk) to the workstation (on the desk). They say that they have done
it at other sites and it works. I remember reading that the
T-connector must always be directly attached to the workstation. We
already have a test setup where one workstation in the middle of the
network is set up this way and all seems to be working.
Can someone please shed some light on this for us? What are the risks
of letting the electricians do what they propose? Are we setting
ourselves up for problems down the road?
Robert Perlberg
Dean Witter Reynolds Inc., New York
{dasys1 | philabs | chuo}!step!perl
-- "I am not a language ... I am a free man!"butzer@rugby.cis.ohio-state.edu (Dan Butzer) (06/15/90)
In article <1692@number1.step.UUCP> perl@step.UUCP (Robert Perlberg) writes: >I once read in this newsgroup that one should not run thin Ethernet >cable between the workstation and the T-connector. Indeed... >I don't remember >what the reasoning was or what ill effects would come of it. We just >had some thin Ethernet cabling done and the electricians are trying to >convince us to allow them to run a line from the T-connector (under the >desk) to the workstation (on the desk). They say that they have done >it at other sites and it works. I remember reading that the >T-connector must always be directly attached to the workstation. We >already have a test setup where one workstation in the middle of the >network is set up this way and all seems to be working. > They are setting you up for lots of grief... Absolutely don't let them do this!!! Attaching line to the T connector will create incredible reflection problems. You might observe that units close together would appear to work, but I'd expect to see many mangled packets. You should be able to satisfy any doubters by connecting a good time domain reflectometer (TDR) to a net wired the way they want to do it. You'll see the reflections. I Suggest that you have the electrician perform this. If they ask what a TDR is or do not have one then I'd question whether they should be installing an Ethernet. Actually, their desire to do this means that they fail to understand even the basics of Etehrnet. If you have a large site to manage, you might want to invest in a TDR. We find it very useful. Thin Our ethernet includes about 350 nodes and many miles of cable. I highly recommend the Tektronix 1503B. Very nice unit especially equiped with the Ethernet options. Unfortunately they are not cheap. (No connection to Tek other than being a happy customer.) --Regards Dan Butzer CIS Network -=- Dan Butzer || butzer@cis.ohio-state.edu IICF/CIS Hardware Support || voice: 614-292-7350 fax: 614-292-9021 "Fire in the hole..." || 2036 Neil Ave, Columbus OH 43210