julian@bongo.uucp (Julian Macassey) (06/07/90)
In article <8642@accuvax.nwu.edu>, utstat!tg@uunet.uu.net (Tom Glinos) writes: > I'm looking for the advantages of RJ45 over RJ11. > Each cubicle that I'm planning will have two jacks. The jacks will > either be phone or data in any combination. > The present data requirements are RS232 and Twisted Pair Ethernet. (I > can't speculate about future requirements) > I'd prefer RJ45 but (bean counters and other bureaucrates) tell me > that RJ11 will suffice. First of all I assume you mean RJ25C not RJ11C. RJ11 is a single pair of wires on a six conductor jack. RJ25C is three pairs of wires on a six conductor jack. Under some circumstances you can run RS-232 type sigs on a RJ25C. In fact DEC do I believe, and I have clients that run serial printers and serial terminals on RJ25 set ups. But the price difference between four pair wire and RJ45s and three pair wire and RJ25s is not that much. But it does give you more flexibility. The labor is the same whether you pull three pair cable or twelve pair. But if you don't pull the right cable the first time, it costs much more to do it over. Once stuff is built and furniture is replaced, it takes three times longer to run cable. Do it right the first time. Yes, you can plug a RJ25 type plug into a RJ45 type jack, so you could wire the RJ45s for regular POTs phones and plug 'em in with no problems. Cable is about $40 a kilofoot (1,000 ft), labour is $40.00 per hour minimum and some interconnects want $80.00 per hour to come out and fix stuff. Yup, one less hour of labor buys another 1,000 feet of three pair or twenty jacks. Explain that to the suit dweebs. One way to handle the bean counter types is show them some official looking docs on RJ45 use and say "See, it has to be this way." There are some AT&T docs on sending RS-232 on RJ45Cs and there is a DEC doc on sending RS-232 on RJ25s. I have never seen these docs, but I am told they exist and I doubt they are an urban legend. I do have AT&T "Data Services Reference Handbook", Vols I - V and see no reference there, although there is lotsa stuff on DB-25s. I believe the AT&T 3B2 docs cover RS-232 on an RJ45c. My motto: "Never pull less than six pair". And sometimes I regret not pulling twenty-five pair. Julian Macassey, n6are julian@bongo.info.com ucla-an!denwa!bongo!julian N6ARE@K6IYK (Packet Radio) n6are.ampr.org [44.16.0.81] voice (213) 653-4495
tg@uunet.uu.net (Tom Glinos) (06/07/90)
I'm looking for the advantages of RJ45 over RJ11. Each cubicle that I'm planning will have two jacks. The jacks will either be phone or data in any combination. The present data requirements are RS232 and Twisted Pair Ethernet. (I can't speculate about future requirements) I'd prefer RJ45 but (bean counters and other bureaucrates) tell me that RJ11 will suffice. tg@utstat.toronto.edu utzoo!utstat!tg
Wayne Correia <wdc@apple.com> (06/09/90)
In article <8766@accuvax.nwu.edu> utstat!tg@uunet.uu.net (Tom Glinos) writes: >I'm looking for the advantages of RJ45 over RJ11. >Each cubicle that I'm planning will have two jacks. The jacks will >either be phone or data in any combination. >The present data requirements are RS232 and Twisted Pair Ethernet. (I >can't speculate about future requirements.) >I'd prefer RJ45 but (bean counters and other bureaucrats) tell me >that RJ11 will suffice. Here at Apple Computer we run six RJ-45's to each and every cube. We don't run eight wires to every jack though, only four. It covers our AppleTalk, twisted-pair Ethernet, proprietary PBX phones, analog phone lines, and ISDN lines. Be advised that most twisted-pair Ethernet and all ISDN basic rate interface lines I know of require an RJ-45 jack even though they don't use all eight wires. Our configuration is what I would call a minimum for any company that had voice and data needs. I also agree with Julian's motto of at least six pair and I also sometimes regret not pulling 25 pair. In short, don't take no for an answer from those who don't understand the real requirements. Wayne Correia (N6RSC) N&C Engineer Developer Technical Support Apple Computer, Inc.
macy@usenet.ins.cwru.edu (06/12/90)
In article <8765@accuvax.nwu.edu>: X-Telecom-Digest: Volume 10, Issue 419, Message 1 of 11 >In article <8642@accuvax.nwu.edu>, utstat!tg@uunet.uu.net (Tom Glinos) writes: >> I'm looking for the advantages of RJ45 over RJ11. >> Each cubicle that I'm planning will have two jacks. The jacks will >> either be phone or data in any combination. > My motto: "Never pull less than six pair". And sometimes I >regret not pulling twenty-five pair. If a customer does not have any circustances that specifically indicate installation of more pairs (such as an active network), then we recomend these: At each typical phone location: two each RJ-25 jack, three pairs wired each, using two separate three pair cables. At primary answering locations, message centers and data intensive areas: three each RJ-25 jacks, three pairs, using three separate cables. (This is to accomodate DSS's, modems, fax's, attendant consoles and such...all of which can be "pair hogs") At known communications intensive locations: one each 25 pr. cable and two each RJ-25's under separate three pair cable. This is suggested to allow the use of certain services that object to sharing a cable with standard phone lines that ring with 100 VAC. (Certain twisted pair LAN's and other data types do not like the inducted transients from ring generator in adjacent pairs). We have found several vendors who make very nice double RJ-25 jacks in surface and flush mount versions. Getting a technophobic customer to agree to pay for all this wiring is another matter entirely. Many customers still do not understand that the quality and quantity of the wiring is _far_ more important than the way the phones look or feel ... or the name on the switch for that matter ... Phone systems come and go ... wiring is forever (if you do it right!) Another free consulting service from... Macy M. Hallock, Jr. macy@NCoast.ORG uunet!aablue!fmsystm!macy F M Systems, Inc. {uunet|backbone|usenet.ins.cwru.edu}ncoast!fmsystm!macy 150 Highland Drive Voice: +1 216 723-3000 Ext 251 Fax: +1 216 723-3223 Medina, Ohio 44256 USA Cleveland:273-3000 Akron:239-4994 (Dial 251 @ tone) (PLEASE NOTE: the system name is "fmsystm" with no "e", *NOT* "fmsystem")