Date: Thu, 16 Jul 2009 16:30:21 -0500 From: "Dean Weimer" <dweimer@orscheln.com> To: <freebsd-questions@freebsd.org> Cc: dkelly@HiWAAY.net Subject: Re: 5000' Ethernet? Message-ID: <CACC65656ED5C44FBA651F3D2B99B8081E4AE1CF@neuman.orscheln.oi.local>
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>Not directly FreeBSD related, but how much of a chance is there that = two >machines could communicate directly over 5,000 feet of cat5 with no >special hardware? > >IIRC the classic Ethernet problem limiting the distance between the >farthest points on a network had to do with timing and collisions. If >these two NICs are configured full duplex then it seems one would have >no idea how far away the other was due to timing issues. > >100baseT uses lower power drivers than 10baseT, so perhaps 10baseT = would >work better. >In any case, have boxes of cat5 on order so as to find out myself. >Are there any particular range extenders you have used and would >recommend for making this task a sure thing on the first try? Perhaps I >should put an inexpensive Ethernet switch at each junction to serve as = a >regenerative repeater? I must say that all the information about Ethernet you have gotten about = this has been quite interesting , but it seems a lot of people forgot = that a simple answer is often the best answer. Basically you don't need = to know all the info about timing and how Ethernet handles collisions. = What you do need to know is that many people have research this, and = that's why Cat5 cable standard has a maximum length of 100 meters or 328 = feet, they have found this to be the maximum length that it reliably = works. In order to go 5000 feet, you would actually need 15 repeaters. = I have never tried to string that many switches or repeaters together = though in my experience if you buy this many low end switches you will = likely have one bad one in the bunch. Plus there's a lot of places you = would need power, and if this is outside now you have to take the = weather into account. It's unfortunate that wireless was ruled out as this would be the = easiest method, and likely the cheapest. The next option I would look = to is definitely fiber as you had mentioned before. I have only ordered = fiber through our installer they come out string it polish and terminate = the ends. Then we just plug in the patch cables. As for a supplier I = checked some of the major vendors we use for cabling, they all offer = only patch cables for fiber, my guess is that if you need to buy a = spool, it would have to be from a whole sale outfit, and then you would = need someone to put the ends on. Your best bet would be to search for = data and communication cable installation services in your area. I = would still quote wireless if it's feasible in the location as your = customer (or management if this is for an in house operation) may change = their mind after presented with the cost of a temporary fiber = installation, and the problems a cat5 run would require overcoming. Hope this helps some, Thanks, =A0=A0=A0=A0 Dean Weimer =A0=A0=A0=A0 Network Administrator =A0=A0=A0=A0 Orscheln Management Co =A0=A0=A0=A0=A0Phone: (660) 269-3448 =A0=A0=A0=A0 Fax: (660) 269-3950
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