kbrown@irs1.UUCP (Ken Brown) (06/21/87)
I have found myself in the position of trying to purchase a PC network for a client in another city, dealing by long distance with a vendor in that city. The network will consist of 8 workstations and an AT clone for a server. The vendor wants to install a Novell system which is fine, but he insists that the hardware has to be ETHERNET boards with coaxial cabling. The price of the boards is not bad (about $400 each) but the cost of the coaxial cabling ($3-$4 per foot) is really hiking the cost of the system. I know very little about networks so I am not able to tell whether what is telling me is really true or if that is just the system they prefer to work with. My question is, is it possible to run a Novell system using twisted pair wiring with the appropriate network cards? The longest run in the system should be no more that 40 ft. if that makes any difference. Also, if we forced them to switch to a 3Com system could that be run over twisted pair? Thank you in advance for any help you can give me. Ken Brown kbrown@irs1.UUCP Phone numbers: 301 229-3000 (Mon.) or 202 663-7740 (Tues.-Thurs.) ...seismo!dolqci!irs3!irs1!kbrown
backman@interlan.UUCP (Larry Backman) (06/23/87)
In article <239@irs1.UUCP> kbrown@irs1.UUCP (Ken Brown) writes: > >prefer to work with. My question is, is it possible to run a Novell >system using twisted pair wiring with the appropriate network cards? >The longest run in the system should be no more that 40 ft. if that >makes any difference. Also, if we forced them to switch to a 3Com system >could that be run over twisted pair? > [] My company, Micom - Interlan, as well as our various competitors make StarLan cards, that run the AT & T Starlan access method over "regular" twisted pair phone wiring. I emphasize "regular" because not all twisted pair is created equal. Starlan currently runs at 1 megabi. The competitor of ours that you mention has announced a twisted pair Ethernet product that runs at 10 megabit. I don't know if it is currently available. So, the answer is yes. Novell runs over twisted pair. But, be careful, Novell's software is only as good as the media that it runs on. Larry Backman Micom - Interlan, Inc.
ron@topaz.rutgers.edu (Ron Natalie) (06/23/87)
1. Yes you can run Novell over other than Ethernet cards (such
as the Starlan twisted pair). I have no experience with this
so I can't tell you about relative performance.
2 You are being ripped off for Ethernet cable. We buy teflon coated
thick ethernet cable (the 1/2" yellow) stuff for much less than $2/foot.
PVC jacketed stuff is available for .40/ft. Most PC's are hooked up
with the thinwire RG58U which is even cheaper. Stop buying your
cable from INMAC.
-Ronrwhite@nu3b2.UUCP (Robert C. White Jr.) (06/24/87)
In article <239@irs1.UUCP>, kbrown@irs1.UUCP (Ken Brown) writes: > > The vendor wants to install a Novell system which is fine, but > he insists that the hardware has to be ETHERNET boards with coaxial cabling. > The price of the boards is not bad (about $400 each) but the cost of > the coaxial cabling ($3-$4 per foot) is really hiking the cost of the > system. > On a semi relate issue, and by way of an answer... More or less at this point they [the vendor and customer] are asking you to set a building wire standard. Almost every major producer has thrown coax away. [could you immagine running two twisted-pair and one of two coax routes to every place a desk MIGHT be placed in an office?] STAY AWAY FROM COAX AT ALL COSTS. It becomes impossible to route in any quantity unless you have a dedicated riser space [we filled to capacity, a four by six foot riser] We have gone to "STARLAN" <an AT&T product> which requires two pairs for each station [four if you dasy-chain them] the other two pairs in an four pair may be used to carry voice/digital voice/data lines [with the jacks on the board providing splitters at the customer end but requireing 66-blocks or adapters at the phone room. Acording to "the" man at local supercomputer lab the 10mbs rate of an ethernet gets throtled down two under 1mbs after accounting for collisions, retransmitions, and frameing. Starlan is rated at 1mbs but you get a (1) colision for every thousand (1000) packets on a bad day [if my monitor tells me true] so it evens out [they say they are going to speed it soon, should be nice] STARLAN is a "garenteed deleviery, connection-mode service" which means that each server has some software selectable limit which is frequently quite small [16 machines on an MS-DOS machine, 32 on a 7300, 128 on a 3Bx] at it's largest value. even though that sucks, for a small instalation [as in the 8 you mention] it works well, if the system adds any UNIX machines the same lan will act as a terminal bridge [each PC may get, and use normaly, the login prompt] by virtue of the "connection mode" arcitecture and most of the bizzare peices available will be able to keep over 40,000 addresses in memory <i.e. bridge cards, etc> so the system can grow in weird ways. If and when you try to go the other systems, have them present you with a sample of the media before you make a decision... Horror Story: A company I know went with "Token Ring" form IBM because it ran on "dual twisted pair" when they discovered what kind of sheath those two pair were in, they realized they would have been better with coax. 1) each pair is about the sixe of zip-cord [like on a table lamp] 2) each pair is wrapped in shielding. 3) the pairs are held together by a nilon sleve. 4) the sleve is wrapped by a structural member, which doubles as an insulation rip-strip 5) the entire assembly is shielded and wrapped in a three layer insulating material. 6) the MINIMUM bend diameter, as stated by the manufacturer, is 10 inches. [as in no sharp corners] 7) the connectors are about 1.5 inches [cubic] with two double interlocked termination flanges for acheiving the electrical connections Try routing that through your office sometime. The little things like this are what some lan manufacturers don't tell you when you order a "high speed twisted pair connection" Incidently the standard for the STARLAN is four pair phone cord, and no I don't work for AT&T, it just happens to be what worked for us. Robert. Disclaimer: My mind is so fragmented by random excursions into a wilderness of abstractions and incipient ideas that the practical purposes of the moment are often submerged in my consciousness and I don't know what I'm doing. [my employers certainly have no idea]
hedrick@topaz.rutgers.edu (Charles Hedrick) (06/24/87)
I certainly have no objections against twisted pair, if you can get the necessary speed on it. But I am mystified about your advice to stay away from coax because of space. Your comments seem to imply a separate piece of coax to each office. Some technologies may do that, but Ethernet and similar LAN's certainly don't. With traditional Ethernet (i.e. not the new thin Ethernet), you run one piece of coax down the hall, and install a tap outside each office, or install a group of taps for small clusters of offices. Of course the actual topology depends upon the size of your building and your data rates. But it would be unusual to have more than 2 or 3 pieces of coax running between floors, even in an installation with lots of high-data rate workstations. We certainly have problems with RS232 cables filling up our conduits, but we breath a sigh of relief when we move to Ethernet-based terminal servers, precisely because the coax between floors takes up almost no space compared to older wiring. The comments you repeat about data rate on Ethernet are probably based on slightly imprecise wording by your informant. It is quite true that it is unusual to see more than 1Mbit/sec in a single conversation on an Ethernet. However it is possible to have several 1Mbit/sec conversations at a time. The other 9Mbit/sec is not taken up by collisions and retransmissions. It is unused. The reason a single conversation doesn't use the full bandwidth is that no LAN software that I know of is designed to put packets onto the network at that high a rate. My understanding is that the market pressure for twisted pair is because of buildings that have lots of twisted pair installed for phones, and find it impossible for political reasons to install any kind of new cable whatsoever. The impression I have gotten from the trade press is that with the advent of lower-cost Ethernet interfaces, Ethernet is now overtaking the proprietary networks. Of course if you are just going to have a few PC's, it doesn't much matter. But as soon as you decide you want to connect to a minicomputer, or you get a Unix-based workstation, or anything else changes, you'll wish you had gotten a network that every vendor under the sun supports.
steve@teletron.UUCP (Steve Tse) (06/25/87)
In article <764@nu3b2.UUCP>, rwhite@nu3b2.UUCP (Robert C. White Jr.) writes: > We have gone to "STARLAN" <an AT&T product> which requires two pairs for > each station [four if you dasy-chain them] the other two pairs in an > four pair may be used to carry voice/digital voice/data lines [with the > jacks on the board providing splitters at the customer end but requireing > 66-blocks or adapters at the phone room. > Starlan is rated at 1mbs but you get a (1) colision for every > thousand (1000) packets on a bad day [if my monitor tells me true] so > it evens out [they say they are going to speed it soon, should be nice] > According to this follow-up article, it looks like you are an expert in StarLAN. I think you may be the right one to answer the following questions that I posted weeks ago. # Has anyone had experience with AT&T's StarLAN network? # I was wondering how good is the performance of this 1 Mb/s, # twisted pair, CSMA/CD network in terms of utilization, throughput, # latency, end to end delay and capacity. # Since the StarLAN using an inverted tree hierarchical star topology, # each message sent by a node has to propagate to the HHUB through all # the imtermediate levels and back to the node through the same route. # Will this cause tremendous of delay and lower the throughput of # the system ? Thanks, ncc!teletron!steve
dd@ariel.unm.edu (06/28/87)
In article <239@irs1.UUCP> kbrown@irs1.UUCP (Ken Brown) writes: >... >The vendor wants to install a Novell system which is fine, but >he insists that the hardware has to be ETHERNET boards with coaxial cabling. >The price of the boards is not bad (about $400 each) but the cost of >the coaxial cabling ($3-$4 per foot) is really hiking the cost of the >system. Shoot the vendor. I assume you are using 3-Com E'net cards (to us, about $400), but this $3-4/ft figure sounds like TEFLON THICK ETHERNET, instead of the nice THIN ETHERNET, which is perfectly adequate in limited distance configurations. It costs about $0.25 per foot for the wire; connectors are a little expensive, but not so expensive as to drive the price to $3/ft. -Don Doerner University of New Mexico Computer and Information Resources and Technology {gatech ucbvax}!unmvax!ariel!dd