Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!uwm.edu!src.honeywell.com!msi.umn.edu!noc.MR.NET!jhereg!andrew From: andrew@jhereg.osa.com (Andrew C. Esh) Newsgroups: comp.dcom.lans Subject: Re: 10Base-T hubs Message-ID: <1991Apr15.222026.9922@jhereg.osa.com> Date: 15 Apr 91 22:20:26 GMT References: <1582@vtserf.cc.vt.edu> <1991Apr9.221136.12326@jhereg.osa.com> <1991Apr12.013427.24895@netcom.COM> Distribution: usa Organization: Open Systems Architects, Inc., Mpls, MN Lines: 65 In article <1991Apr12.013427.24895@netcom.COM> cmilono@netcom.COM (Carlo Milono) writes: >In article <1991Apr9.221136.12326@jhereg.osa.com> andrew@jhereg.osa.com (Andrew C. Esh) writes: >>In article <1582@vtserf.cc.vt.edu> jcrowder@GroupW.cns.vt.edu (Jeff Crowder) writes: >>>In article <1991Apr08.171237.19978@shl.com> phil@shl.com (Phil Trubey) writes: >>> >>>>As fas as the hype being invented, every new installation that I've dealt >>>>with (I work for a systems integrator) in the last year has been 10BaseT. >>>>The *only* place where I would recommend coax is in a lab environment >> >>Only a lab environment? You must realize that some sites are more spread >>out than what 10baseT can reach. Sure, it will work for one floor of a >>small to medium sized building, but sheer physics drives you up into >>ThinNet, ThickNet, and Fiber when the physical seperation between nodes is >>great. 10baseT just doesn't go more than 400 ft. The company I work for is >>called upon to design nets for buildings up to a quarter MILE on a side. >>10baseT is great for an office area, but you need something else for >>distance. >>> >You can daisy-chain MPR's at least up to four; at 300' each, you can >safely install a 10BASE-T network whose far-to-near end components >approach 1500' - you need to factor the Round-Trip-Bit-Delay using >the constructs of the MPR and the cable length. Using higher quality >wire (i.e., AT&T's 2061 cable), you can run even farther!\ > >To go one step farther, there *really* isn't a four-repeater RULE in >10BASE-T, and I have seen more than six MPR's strung out. However, >for Distance (with a Capital-D), nothing beats FOIRL for that, unless >you have the bucks for FDDI. >-- >+--------------------------------------------------------------------------+ >| Carlo Milono: cmilono@netcom.apple.com or apple!netcom!cmilono | >|"When a true genius appears in the world, you may know him by this sign, | >|that the dunces are all in confederacy against him." - Jonathan Swift | >+--------------------------------------------------------------------------+ I'm sure that given any cable type, there is a combination of boxes that will make it run for miles. The problem with 10baseT for distance is that we are not trying to cover a square quarter mile of area, we have departments spread out in pockets all over that area. 10baseT in the department is fine. We need something else to cover the 500' runs in between. Up 'til now it's been Thinknet, but that's too small, and we needed to integrate voice and other stuff, so FDDI. 1/4 mile square manufacturing facilities are of a scale that FDDI becomes cost effective, mainly because nothing else provides the kind of bandwidth these folks wolf down. Yikes! "Imagine all the Routers, sending packets by. Imagine all Transceivers, pulling transmit high. Imagine all the users, writing to their files. You may say ... I'm a wiener, But I'm not the only one. When I'm through as a weiner, All the nets will be as one." (apologies, John Lennon) -- Andrew C. Esh andrew@osa.com Open Systems Architects, Inc. Mpls, MN 55416-1528 Punch down, turn around, do a little crimpin' (612) 525-0000 Punch down, turn around, plug it in and go ...