km@mathcs.emory.edu (Ken Mandelberg) (12/14/89)
Our campus network hardware people have adopted the following
plan for wiring buildings for "networking". They wire every
office with "type 2" twisted pair cable to a phone closet.
They like the flexibility of this, since they can later decide
whether to do twisted pair ethernet, token ring, rs232, etc.
I guess this is the IBM wiring plan.
Does this seem like a reasonable approach? I thought ethernet
over twisted pair was mainly for buildings with exising cabling
in the walls. Our people are doing new wiring this way even
when they know its for ethernet.
--
Ken Mandelberg | km@mathcs.emory.edu PREFERRED
Emory University | {decvax,gatech}!emory!km UUCP
Dept of Math and CS | km@emory.bitnet NON-DOMAIN BITNET
Atlanta, GA 30322 | Phone: (404) 727-7963WIMMER%telcom@rvax.ccit.arizona.edu (12/15/89)
Ken, Until the IEEE 10baseT specifications are published next year there really is no standard for ethernet over twisted pair. Many vendors seem to have defined what they think the proposed standard will be and are at least announcing products to support it. Most vendors are producing products to work on UTP (unshielded Twisted Pair) for ethernet and even big blue has it's type 3 media filters to allow Token Ring to work on UTP. Our campus has chosen to use the AT&T PDS wire plan and we are about to complete the rewiring of most buildings on campus to conform to PDS specs. We install dual RJ-45 (106bfd) jacks for voice and data use in every office. (there are suggestions for the quantity of these dual V/D jacks needed for every size room) At this point the voice jack (4 pr UTP) will be used only to connect to the new 5ESS switch (which will cutover in Feb90) and the middle 4 pins of the RJ-45 data jack is used/reserved for the campus low speed data switch (IDX-3000's). Our telecomm engineering group has/does authorize the use of the unused two pair of the data jack for such things as printer sharing device connections, workgroup & departmental LAN's and in some cases we have used them to supply video to an overflow room next to an instructional seminar or lecture. We have started to test different vendors UTP ethernet products but as yet have not made a decision as to which one to support. Many of the Research Labs and departments have chosen to install departmental/building thick coax with AUI bulkhead mounts off xceiver taps instead of attempting to "beta test" the as yet unpublished 10baseT standard for UTP Ethernet. We have tested or have currently installed on UTP the following LANs; Arcnet UTP hubs and PC cards using LANtastic's Software Arcnet UTP Hubs & PC cards using Novell Software Arcnet UTP Hubs & PC cards using Arcnet Software Cabletron UTP Ethernet concentrator & UTP transceivers Synoptics UTP Ethernet concentrators & UTP transceivers IBM Token Ring MAU's and IBM Token Ring PC cards using Novell software The MAU's between floors are connected using IBM type 1 cable AT&T StarLAN using AT&T Hubs, PC cards, & software
kwe@buit13.bu.edu (Kent England) (12/15/89)
In article <4762@emory.mathcs.emory.edu> km@mathcs.emory.edu (Ken Mandelberg) writes: > I thought ethernet >over twisted pair was mainly for buildings with exising cabling >in the walls. Our people are doing new wiring this way even >when they know its for ethernet. >-- Many of us network managers like Ethernet over twisted pair because the topology/architecture is much easier to manage than a bus architecture/topology. The technical performance on the medium is a secondary consideration to the standardization of the medium and the star topology. Follow-up to comp.dcom.lans or the big-lan list at syracuse. Lots of discussion on these issues there. tcp-ip doesn't care whether it's twisted pair or baling wire. :-)
John_Robert_Breeden@cup.portal.com (12/16/89)
> >Ken, > >Until the IEEE 10baseT specifications are published next year there really is >no standard for ethernet over twisted pair. Many vendors seem to have defined >what they think the proposed standard will be and are at least announcing >products to support it. Most vendors are producing products to work on UTP >(unshielded Twisted Pair) for ethernet and even big blue has it's type 3 media >filters to allow Token Ring to work on UTP. > >We have >started to test different vendors UTP ethernet products but as yet have not >made a decision as to which one to support. Many of the Research Labs and >departments have chosen to install departmental/building thick coax with AUI >bulkhead mounts off xceiver taps instead of attempting to "beta test" the as >yet unpublished 10baseT standard for UTP Ethernet. > >We have tested or have currently installed on UTP the following LANs; > >Arcnet UTP hubs and PC cards using LANtastic's Software >Arcnet UTP Hubs & PC cards using Novell Software >Arcnet UTP Hubs & PC cards using Arcnet Software >Cabletron UTP Ethernet concentrator & UTP transceivers >Synoptics UTP Ethernet concentrators & UTP transceivers WHAT IN GOD'S NAME WILL CHANGE BETWEEN THE 10BASET DRAFT AND THE FINAL STANDARD THAT WOULD OBSOLETE THE EXISTING VENDOR'S PRODUCTS THAT CONFORM TO THE 10BASET DRAFT TODAY??? - NOTHING!!!!!!!!!!! None of the basic specs for 10baset in the drafts has changed (or will change) before the standard is voted on - and the proof of that state- ment is the ability to "plug-and-play" with the conforming vendors who manufacture to the 10baseT draft today (AT&T, HP and UB to mention a few). Given that ability I'll beat the cost of hardware by having MANY vendors to choose from today over using those vendors that keep users locked into TRUE PROPRIETARY architectures (read Synoptics and Cabletron). Don't knock those vendors that are trying to level the playing field by activly supporting and MANUFACTURING to standards (or well defined draft standards) by buying into the hype "that the draft isn't defined well enough to build product to" - that's hog wash! But then if I supported ARCnet, Novell, Cabletron and Synoptics standards would a moot point. standard IBM Token Ring MAU's and IBM Token Ring PC cards using Novell software The MAU's between floors are connected using IBM type 1 cable AT&T StarLAN using AT&T Hubs, PC cards, & software