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Networking IT

Should Network Cables Be Replaced? 524

Jyms writes "As technology changes, so hubs routers and switches are upgraded, but does the cabling need replacing, and if so, how often? Coax gave way to CAT 5 and CAT 5e replaced that. If you are running a 100Mbit/s network on old CAT 5, can that affect performance? Do CAT 5(e) cables get old?"
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Should Network Cables Be Replaced?

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  • Cat6 (Score:5, Informative)

    by I_am_Rambi ( 536614 ) on Tuesday April 21, 2009 @04:36PM (#27666417) Homepage
    Just like any cable, cables will break. So, yes, they do get old.

    Also, there is cat6 cables out with better specs and can handle at least up 10gb/sec.
    • Re:Cat6 (Score:4, Informative)

      by JCSoRocks ( 1142053 ) on Tuesday April 21, 2009 @04:40PM (#27666493)
      Yeah, we've had network cables fail. Even patch cables. It's rare, but it happens. If you get the chance you might as well replace your cabling. Besides, regular CAT 5 isn't going to get you over 100Mbs - and that's no fun.
      • Overkill... (Score:5, Insightful)

        by volxdragon ( 1297215 ) on Tuesday April 21, 2009 @05:01PM (#27666829)

        Bull - you can do Gig-E (IEEE 802.3ab) perfectly fine up to the 100 meter spec over regular old CAT-5 - []. You don't need CAT-5e or CAT-6 unless you have incredibly shitty cable, splices, runs approaching max length, or too many patch panels along the route (IE, a crappy install in the first place).

        Now, I personally use shielded CAT-6 for everything, but I believe in overkill :)

        • Re:Overkill... (Score:5, Informative)

          by Vancorps ( 746090 ) on Tuesday April 21, 2009 @05:13PM (#27667029)

          While you can link at those speeds with Cat5 you cannot actually get those speeds. Usually it tops out about 200-400mbit for me when I've tried. For most uses that's perfectly fine but in some cases it's not like my entire graphics and video editing departments. Servers are all connected with Cat6 if they use a lot of bandwidth.

          I ran into this problem in Vegas as the place only had Cat5 connecting all the rooms to their closets so I had to use LACP trunking to get my bandwidth up.

        • Re:Overkill... (Score:5, Interesting)

          by QuantumRiff ( 120817 ) on Tuesday April 21, 2009 @05:21PM (#27667175)

          I have had all sorts of problems at work with my cabling.. All sorts of stuff worked great with the initial 10Mbt network. Now it is getting flaky at even 100MB, let alone gigabit. Occasionaly, we'll troubleshoot a wire, take off the faceplate at the wall, and find about 4-5 inches of unsheilded wired before its punched into its jack. Sometimes, its just one pair or two. I actually had a cable that someone made longer, by stripping the wires, twisting them together, and using MASKING tape to hold them together. That one was a treasure to find. Now, keep in mind, 80% of my cabling is awesome, and fully to spec. However, i'm guessing one of the guys working on the team that installed this cabling, long before I came, was of the "good enough" mentality, and its costing quite a bit to fix now.

          • Re:Overkill... (Score:5, Interesting)

            by Kintanon ( 65528 ) on Tuesday April 21, 2009 @05:52PM (#27667653) Homepage Journal

            That's what happens when ELECTRICIANS run your data cable.
            We came in behind an electrician that had taken every cable in the wiring closet, stripped the shielding off to about 1 foot from the wall, and neatly bundled each color of wire pairs together for about 100 cables. So we had a huge bundle of blue, then one of blue/white, then one of orange etc... pairs.
            Same guy tried to run network jacks in serial the way you can do telephone cable or electrical.
            Same guy would strip 4-6 inches of shielding off before punching down (incorrectly) at the jacks.

            Electricians just see it as low voltage electrical. The master electrician running the crew might know the difference, but the apprentice who is actually doing the work has no clue.

            So please, hire a real data wiring company to run your cables.

            • Re:Overkill... (Score:5, Insightful)

              by wilby ( 141905 ) on Tuesday April 21, 2009 @07:39PM (#27668929)

              Please don't blame "Electricians".

              Whoever did your cabling was unqualified to do the work he was hired to do. (Usually the the fault of whoever hired them.)

              There are several electrical contractors who are qualified to do data work.

              • Re:Overkill... (Score:5, Interesting)

                by RajivSLK ( 398494 ) on Tuesday April 21, 2009 @07:56PM (#27669165)

                Whoever did your cabling was unqualified to do the work he was hired to do. (Usually the the fault of whoever hired them.)

                I don't follow... When I get a quote from somebody who claims to be capably trained for certain task how is it my fault when he screws up? The long and short of it is that thousands of people every year get screwed over by trades people who claim skills they don't have (Some of the scamers are quite good at it too) and the blame lies mostly with these unscrupulous people.

            • Re:Overkill... (Score:4, Interesting)

              by SuperMonkeyCube ( 982998 ) on Tuesday April 21, 2009 @07:59PM (#27669209) Homepage
              I will second wilby's comment and say that Electricians are not the problem. Any licensed contractor that's worth his salt will know what his capabilities are and act accordingly. The BICSI standards have been in place for a long time, and BICSI has done a great job getting the word out to both electricians and low voltage contractors about how to do things to industry standard. If someone wires CAT5 like it's something else, then you have a dumbass problem, not an electrician problem. All of the jack vendors have done a great job disseminating information about how to do CAT5, and several have certified installer programs aimed at getting people putting together a system, not just wires. If field personnel cannot avail themselves with current information then I wouldn't even trust them to put in a fluorescent dimmer or a thermostat made in the last ten years.
            • Re:Overkill... (Score:4, Informative)

              by binaryspiral ( 784263 ) on Tuesday April 21, 2009 @10:29PM (#27670475)

              Bullshit - you just hired stupid electricians. Probably lowest bid on the job, right?

              We let our contracted electricians run our coax, cat5e, 110v, 208v, and 480v - and they did a great job. Even labeled all the ports on the patch panels, each end of the cables, and even used the cable management we installed.

              Data wiring companies are just over priced electricians.

          • Re:Overkill... (Score:5, Informative)

            by Bruce Perens ( 3872 ) * <> on Tuesday April 21, 2009 @05:57PM (#27667743) Homepage Journal

            Although shielding is nice to have, it's not necessary for network cable because network cable is balanced twisted pair. Indeed, most high-performance network cables are not available with shielding, they can't maintain the spec with a shield in the jacket. It might be that your cable is older.

            If you do have shielded cable, don't ground both ends!!! Bring all cables at one end to a common ground, and let the other end float. Otherwise, you will create a ground loop and actually make the noise worse.

            • Re:Overkill... (Score:5, Informative)

              by lgw ( 121541 ) on Tuesday April 21, 2009 @06:19PM (#27668043) Journal

              Grounding one end makes the shielding at the ungrounded end an efficient antenna, and can actually increase the radiation from the cables.

              Cable shielding isn't a good way to avoid inteference with the signal on the cable, and isn't a good way to avoid radiation by the signal on the cable, unless properly terminated for one specific frequency (or narrow frequency range). One or both ends of the shielding would need to be coupled to case ground by a capacitor chosen for the frequency that you want to shield.

              Shielded cable at this frequency is likely to cause more harm than good. There's usually little need to shield against common-mode interference, and I've never heard of shielded cable being used in a TEMPEST set-up (carefully matching impedances is the best way to avoid emissions, creating giant gorund loop antennas is not).

              • Re:Overkill... (Score:5, Insightful)

                by evilkasper ( 1292798 ) on Tuesday April 21, 2009 @06:35PM (#27668221)
                Truthfully if you think you need shielded, look at fiber, the prices have come down, and while copper isn't as expensive as it was a few months back it is still up there. You'll shell out a bit more but you'll have a better network for it.
              • Re: (Score:3, Informative)

                by Bruce Perens ( 3872 ) *
                One reason for shielding is to avoid induced currents in the signal pairs during a nearby lightning strike. And then DC ground on one side and float on the other would be correct. Of course fiber works well for runs that are long enough for fiber to make sense. But of course at the end you go to copper.
              • Re:Overkill... (Score:4, Informative)

                by adolf ( 21054 ) <> on Tuesday April 21, 2009 @08:21PM (#27669453) Journal

                Sure, it's a little like an antenna, insofar as a Faraday cage is.

                But grounding the shield at both ends creates ground loops. You might not notice them right away, but you sure will the first time the MOVs in the surge suppressors at one end or the other shunt a spike to ground, and some of that current decides that its preferred path to ground is over your STP Cat5.

                Eventually, after you blow up enough switch ports, you'll stop doing it that way.

                It's generally pretty bad form to ground both ends of any shielded wire that traverses any real length.

          • by Nefarious Wheel ( 628136 ) on Tuesday April 21, 2009 @07:19PM (#27668705) Journal
            I tend toward wireless for the home network. If I need to replace the air, I open a window.
        • Re:Overkill... (Score:5, Informative)

          by Sandbags ( 964742 ) on Tuesday April 21, 2009 @05:44PM (#27667505) Journal

          5 and 5e are only rated for 100MHz per pair, so although you can get link speed aggregated at 1000bT, your max throughput due to crosstalk, signal reflection, and EMI is going to limit your switch to a speed closer to 300-400Mbit. Many switches will detect Cat-5 issues and downgrade your link connection automatically on problematic runs.

          Connector quality has more to do with the connection quality than the cable itself. 5e simply has tighter specs to maintain. Really, there's not much of a difference, especially is you're using good patch panels.

          Cat 6 runs 250MHz per pair, tru gigabit speeds are supported.

          10G over copper is most commonly limited to 15M, and requires special 4 lane copper cabling, not Cat6 cabling. It's similar to Infiniband in design. A Cat 6 option was later offered, though few companies support this format. It's limited to 66m, and suffers similar bandwidth issues due to signal quality that running Gig-e over Cat-5 exhibits. Cat6a cabling can be used for 100m 10G deployments. Note this requires 650MHz Cat 6 cable ends, not 250MHz cat 6 cable ends as are normally deployed, for which there is a difference, and also requires 10G rated patch panels. Cat 6 cable can come in one of 3 thicknesses (guage). only one of these is commonly reccomended for 10G speeds.

          Cables do go bad over time, due either to environmental factors or movement. Exposure to direct sunlight is bad fort cabling. Non-constant temperatures is also a cause of degredation.(cables in plenem space or inside walls tend not to remain at constant temperatures). Oxidation of the copper connector is the most common failure. higher quality cables and patch panels use silver, gold, or other corrosion resistant metals for this reason. Many cables are also made with lower quality plastics that simply fail over time (some are practically designed that way I sometimes feel). When the plastic fails, the cables corrode quickly.

          More often I find a switch port fails before a cable (usually because someone plugged something in they should not have, or a charge makes it way into the cable due to being too close to a power cord, or long term exposue to magnetic fields causes elecrical resistance and damages the switch over time.

          typically, I'd leave cables in place until a hardware upgrade or data bottleneck justifies the change. ALLWAYS use high quality cables rated for the installation location. lower guage (thicker copper) are generally better, but they should ALLWAYS be within spec. Buy cables from companies that offer 20 year lifetime warranty. (Hitachi, Mowhawk, etc) Have them installed by professionals who back that warranty and use properly rated panels and punch downs and you should have no issues. Anytime you;re running cables, allways run a class of cable 2-3 tiers better than your current needs, and for workstation drops or other complicated runs, allways run spares (the labor typically costs more than the cable, and running 2 or 3 at once costs less than 1 now and 1 later). Use cable trays or hooks EVERYWHERE, never let cables lie on ceiling tiles or underneath floors in channles.

          This sounds like overkill, and probaly is for a small business, but when you have 14,000 desks in your copmpany (most with 2 netowrk and 2 phone drops) and over 3,500 servers, labor to replace cabling tallies in the millions of dollars...

          • Re:Overkill... (Score:5, Informative)

            by Anonymous Coward on Tuesday April 21, 2009 @07:29PM (#27668825)

            5 and 5e are only rated for 100MHz per pair, so although you can get link speed aggregated at 1000bT, your max throughput due to crosstalk, signal reflection, and EMI is going to limit your switch to a speed closer to 300-400Mbit. [...] Cat 6 runs 250MHz per pair, tru gigabit speeds are supported.

            That is incorrect. Gigabit Ethernet (1000BASE-T) uses the same bandwidth as Fast Ethernet. The higher speed is achieved by using
              1) all four pairs (Fast Ethernet uses two),
              2) each pair in both directions (Fast Ethernet uses one pair to send, one to receive), and
              3) a more efficient encoding (more bits per baud).
            The full Gigabit Ethernet speed is specified for Cat5 cables.

      • Re:Cat6 (Score:5, Informative)

        by Holmwood ( 899130 ) on Tuesday April 21, 2009 @05:06PM (#27666919)

        Foresight certainly helps. I wired my home twelve years ago with 622 Mbit/s teflon-coated copper twisted-pair ATM wiring. It was the best I could easily (and cheaply since it was left over from a large commercial project) obtain. Except as noted below, since then, I've detect no material degradation in cable testing, and, needless to say, it handled the leaps from 10 Mbit/s (1997) to 100 Mbit/s (2002) to 1 Gbit/s (2009) with no difficulties.

        According to a new (borrowed) cable tester, all the runs look capable of sustained 10 Gbit/s.

        At current rate of progress in speed that should take me at least to 2021 before I start noticing that I'm no longer keeping up.

        Of course with my luck, in my area, broadband will still probably be 10 Mbit/s and capped at 90 GB/month.

        In my (admittedly limited) observations, you can have about four sources for run destruction:
        1. Work hardening and breaking due to excessively sharp bending. (Be careful on insulation, and teflon coating = nice -- makes cable much harder to bend sharply)

        2. Oxidation problems especially at the terminal. I've had terminal problems with wiring in an indoor pool area (vapour barrier separating it from rest of the home). Salt water + generated chlorine seem not to like metal in general. People unlucky enough to have installed the Chinese contaminated drywall might have similar problems.

        3. Tension on cable (especially at terminal). Buildings shift, flex, settle, and twist. And not just in earthquakes. Competent installation helps here, especially if you have to redo a corroded terminal and need more run length.

        4. Renovation. Whether it's a nail through the wall, a drill in the wrong place, mistakes can happen.

        5. Animals. Squirrels getting into the attic managing to destroy infrastructure in a friend's house.

        I've not had problems with (1), (3), (4), (5) but friends have. I would assume (5) is not a big danger in most office environments, but one never knows. As I say, my experience is primarily limited to my home and those of friends who've also wired up. And my sole problems have been at the termination point, not with cabling itself.

        My advice is... buy good quality cabling -- better quality than you need. Don't get your installs done by cowboys, and try to think ahead.

        Tough advice sometimes to follow when you don't control the budget.


    • Re:Cat6 (Score:5, Informative)

      by arth1 ( 260657 ) on Tuesday April 21, 2009 @04:46PM (#27666611) Homepage Journal

      CAT6 is a PITA to use residentially. It is much stiffer, due to a "coffee stirrer" embedded in the middle, and doesn't bend well at all. I just downgraded from CAT6 to CAT5e for hooking portables up to my GbE LAN, just because of how unwieldy CAT6 was.
      The CAT6 plugs can also be a problem -- they are by necessity slightly thicker (the strands alternate in height when crimped), which can make them a tough fit for some devices.

    • Re:Cat6 (Score:5, Funny)

      by Walpurgiss ( 723989 ) on Tuesday April 21, 2009 @06:03PM (#27667833)
      Rather than standard cat6, get Denon's super high fidelity cable. []



      Denon's 1.5 meter (59 in.) proprietary ultra premium Denon Link cable was designed for the audio enthusiast. Made from high purity copper wire and high performance connection parts, the AK-DL1 will bring out all the nuances in digital audio reproduction from any of our Denon DVD players with the Denon Link feature connected to a Denon Link enabled Denon A/V receiver. The AK-DL1 employs high level tin-bearing alloy shielding not typically available in commercial cabling, to eliminate data loss caused by noise. Additionally, signal directional markings are provided for optimum signal transfer. Attention to detail when building this cable was used by employing high quality insulation and woven jacketing to reduce vibration and to add durability. Rounded plug levers help prevent breakage.

      For operational and technical assistance 24/7, use our self help Online Support Center, where answers to many common questions can be found."

      If it's good enough for high fidelity audio reproduction, it should be good enough for our crappy data only needs. /smirk
  • Yes (Score:5, Funny)

    by oldhack ( 1037484 ) on Tuesday April 21, 2009 @04:36PM (#27666423)
    For best performance, replace it with a genuine high performance cable like this: []
    • Re:Yes (Score:5, Funny)

      by gavron ( 1300111 ) on Tuesday April 21, 2009 @04:44PM (#27666559)
      They got directional signal markings. It's what cables need.

      Brawndo, the thirst-tamer!

    • Re: (Score:3, Insightful)

      by Dmala ( 752610 )
      I'd love to see the manufacturer's cost of materials for mega priced "audiophile" cables like this. Do they really spend more on "high quality" materials (even if it's useless) or do they just make it out of the same stuff as regular cable and then try to keep a straight face while they take your money?
      • by Sycraft-fu ( 314770 ) on Tuesday April 21, 2009 @05:27PM (#27667285)

        It isn't as though higher grade materials really cost that much more. There are better grades of the materials that go in to a cable. That is the difference between some cheap wire from a hardware store and something like, say, a professional Belden cable. However you'll discover that the cost difference between the two isn't a whole lot. Cheap RG-59 might run you $0.10/foot and Belden 1694A might run you $0.50/foot.

        So yes, they'll often use good materials, because they don't come anywhere near the sales price. For $500 I imagine I could make you a Cat-5 cable using silver conductors if you wanted (silver wire isn't nearly as expensive as people seem to think).

        The markup on "audiophile" cable is so insane they can afford to do things well.

    • Re:Yes (Score:5, Funny)

      by Charles Dodgeson ( 248492 ) * <> on Tuesday April 21, 2009 @05:17PM (#27667107) Homepage Journal
      Agreed. $500 isn't too much to pay for an ethernet cable when your audio depends on it. I keep mine next to my DVD Rewinder [].
    • Re:Yes (Score:4, Funny)

      by Burkin ( 1534829 ) on Tuesday April 21, 2009 @05:44PM (#27667513)
      Yes, but that will do you no good if your CD is magnetized! You need to rush out and buy a CD demagnetizer to get the full audio experience! []
    • Re: (Score:3, Funny)

      by Sentry21 ( 8183 )

      Part of the efficiency is the arrows, so the data knows which direction it should go. Otherwise it gets confused and just goes round and round in circles. You can save some money by drawing arrows on the cables you already have. I've done it on all the cables in our office building, and the tests don't show it, but it FEELS faster!

    • Re:Yes (Score:5, Funny)

      by rlh100 ( 695725 ) on Tuesday April 21, 2009 @06:35PM (#27668223) Homepage

      Oh yes. The high purity copper and alloy tinned shielding make a *HUGE* difference to my digital audio. I find that it transmits the ones and zeros with much higher and crisper definition. The braided cloth covering really does reduce vibration on the cable. I find my music is much more in tune and never wavers due to cable vibration. I am also sure that the electrons flowing in the right direction for the cable are the reason my is sound bigger with more warmth. And don't get me started on the improved imaging. I now know exactly where the sound is coming from. Fantastic, definitely five stars.

      I think these high definition Ethernet cables made as much an improvement as my $100 WattGate IEC power cords did. I am amazed at how replacing 6 feet of power cord can negate the ill effects that hundreds of feet of plain copper house wiring has on my AC power. Truly amazing sound.

      I am currently saving up for a set of triple ought (000) 99.999% pure silver speaker cables. I have been told by my audiophile sales person that these cables will allow me to hear the sound before it leaves the speakers. My only concern is that these dual 3/8" diameter cables are a bit heavy for my floor.

      Al Phile

              "More money than brains"

  • by Chas ( 5144 ) on Tuesday April 21, 2009 @04:39PM (#27666469) Homepage Journal

    You should replace your tired old CAT5 with brand new, all-gold Monster-CAT6+++++++!

    Only $1000 a foot, starting in 10 foot increments!

  • by taustin ( 171655 ) on Tuesday April 21, 2009 @04:40PM (#27666501) Homepage Journal

    I am responsible for a 17 location VPN base WAN for a retail chain. We use Cat5e for everything, but in the end, it hardly matters, because Cat3 at 10 mbps is still over four times faster than the T-1 that it talks to the outside world with.

    But we don't work with large files internally, even here in the corporate office. If one is working with gigabyte sized files on a regular basis, on a local network, it would matter.

    • Re: (Score:3, Interesting)

      by Bruce Perens ( 3872 ) *
      Think about length. Short runs of Cat3 are probably fine for gigabit ethernet. It's when you are up to the specified maximum length that you are likely to run into trouble.
  • by SnarfQuest ( 469614 ) on Tuesday April 21, 2009 @04:41PM (#27666509)


    When it was installed, your old cable had to run signals uphill through the snow, both directions. They didn't have electrons back then, they had to nake do with quarks. Time hadn't been invented yet, so the direction and speed of network traffic was hard to estimate.

    • Re: (Score:3, Funny)

      by PhxBlue ( 562201 )

      Time hadn't been invented yet, so the direction and speed of network traffic was hard to estimate.

      Whereas nowadays, we know exactly how fast the traffic is going, but we have no clue where it is [].

  • "get old"? (Score:5, Informative)

    by nine-times ( 778537 ) <> on Tuesday April 21, 2009 @04:41PM (#27666511) Homepage

    I'm not sure what would "get old" exactly. It's insulated copper, so I think it should be good so long as they aren't damaged. If anyone knows better, feel free to correct me.

    If you want to be sure, though, test them. Transfer files over your network. If the connection is bad, you can try replacing the cable and see if that works. But the fact that Cat6 is out doesn't mean you have to rush out and replace all your CAT5e cables, especially if you're only dealing with normal 100mbps connections. But I use CAT5e for 1gbps connections, and that seems to work fine.

    • by SnarfQuest ( 469614 ) on Tuesday April 21, 2009 @04:49PM (#27666647)

      Coopper can oxidize (turn green) if it isn't protected well. Some cheap old cables may have oxidated to the point that they no longer preform their designed duties, but that would be indicated by the fact that traffic wasn't flowing.

      To check the cables for this problem, simply remove the insulation from the cable and check for oxidation. Replacing the insulation after checking is a somewhat harder problem.

      If the cables still work, aren't disintigrating, and aren't causing problems; then I wouldn't waste the time, effort, and money replacing them.

    • Re: (Score:3, Informative)

      by Andy Dodd ( 701 )

      Depending on the exact insulation and the environment (see a previous post regarding outdoor cabling), the insulation could degrade with age.

      Also, the physical geometry of the cabling is important for high speed networks. If the cable gets moved around frequently, it could degrade to the point where it no longer works.

      There is of course the whole upgradability thing - Cat5 is good enough for 100M, and 5e is good enough for gigabit, but what if a few years down the line you want to go 10GbE? It seems outla

      • Re: (Score:3, Insightful)

        by jra ( 5600 )

        Yes, but -- just like with CPUs -- we are *over* the hump in the S-curve now.

        With a few small exceptions (HD-Video and the like), Core CPUs, a gig or 2 or RAM and GigE are *enough*.

        Really. :-)

    • Re: (Score:3, Informative)

      by Vancorps ( 746090 )
      If your cables are plenum rated and installed appropriately then they will last for quite a long time. Outdoor cabling however doesn't last near as long especially if you're in an extreme climate. I had issues in VT with the freezing and thawing and in AZ I have issues with the sun baking the insulation to the point it becomes brittle. In any case it's easy to test for. Just put a machine on each end, start a ping with progressively larger packet sizes and watch the statistics. If you start getting errors t
  • Gold plated baby! (Score:5, Insightful)

    by Rosco P. Coltrane ( 209368 ) on Tuesday April 21, 2009 @04:41PM (#27666515)

    These people [] should be able to help you.

    Seriously though, what strange question. Either the cable works and you're happy with the bandwidth it provides, or it stops working and you replace it, or you want to upgrade it. What's the complication here?

    • Re: (Score:3, Insightful)

      by Xzzy ( 111297 )

      Because new specs come out for the cables. There was cat 3, and cat 5, and cat 5e, and now cat 6 is out. They are all rated for increasing amounts of bandwidth.

      I haven't yet come into a situation where this has been an issue though. I run gigabit over cat 5 constantly (despite claim that cat 5 is not rated for it), and have never had an increase in errors or interruptions. Which is what I think the OP was asking about.. are the new specifications really necessary?

      In my experience, the answer is no.

  • by WindBourne ( 631190 ) on Tuesday April 21, 2009 @04:43PM (#27666549) Journal
    If you do not, then cracks will appear and bits will start to drip from it. Soon, that drip will become bigger and you will have bytes dropping out. Cheaper to replace them now, then to lose all those bytes. I can be over there next week to replace them all for a low low price.
  • No (Score:5, Insightful)

    by Sycraft-fu ( 314770 ) on Tuesday April 21, 2009 @04:44PM (#27666553)

    Do not replace network cables just to do it. That is a waste of time and money Replace them in two situations:

    1) You are moving to a faster signaling speed and need better cabling. 10mbps requires Cat-3, 100mbps requires Cat-5, 1000mbps requires Cat-5e. Do not run higher speeds on lower standards, it works sometimes but often it "works" in that you get link but there's all kind of errors.

    2) A cable has a fault. Sometimes they will break because of strain. In this case, you need to replace them to make them work.

    Barring that, keep the cable you have. No reason to replace it just for fun. Also no reason to upgrade to new standards without a reason. It isn't as though it makes shit work better. 10mbps is 10mbps no matter if it is on Cat-3 or Cat-6. Also sometimes you get standards that aren't useful. Cat-6 is likley to never be useful for anything. 1gbps only needs Cat-5e, and 10gbps is likley to require Cat-6a. So if you upgraded a Cat-5e network to Cat-6 to prepare for faster speeds, well then you probably wasted your money and will have to upgrade again to Cat-6a if you want 10gbps.

  • by raddan ( 519638 ) on Tuesday April 21, 2009 @04:53PM (#27666693)
    "If it ain't broke, don't replace it with Cat6."

    Seriously, replacing cable is gigantic pain in the ass, when you could be doing better things with your time. Not to mention, it's expensive if you have a large enough installation-- this is why people are spending so much to keep Cat5e creaking along.

    If it's working, and you're happy with it, keep it. If you need something faster, or it doesn't work anymore, or you need to meet new fire codes, well, that answers your question.

    Remember, wires are solid state electronics. There's not much to go wrong there unless you're in extreme environments.
  • by wiredlogic ( 135348 ) on Tuesday April 21, 2009 @04:55PM (#27666723)

    Well terminated cat5 cable will be sufficient for achieving 1Gb/s speeds. What's more important for maximizing your throughput is to ensure that you have your cables properly wired to support full duplex connections. In addition, all passive hubs should be eliminated and replaced with GigE switches, either managed or unmanaged depending on how much control you need.

  • Bad Connectors (Score:3, Informative)

    by ServerIrv ( 840609 ) on Tuesday April 21, 2009 @04:58PM (#27666779)

    We had a contractor wire our office and had no problems until we started using roaming profiles. A few of the connection terminators were bad and only allowed a 1mb/s connection. The computers that had these problems normally only transfered a text files from the server, or surfed the internet and weren't really using more than that bandwidth anyway. So, with large file copies associated with roaming profiles, we finally found the problem. At that point, I distrusted the contractors work and had every connection redone (40 total) and retested to the full 1000mbs our network actually supported.

    So my suggestion is this. Unless someone kicks the cable every day, there isn't much to go wrong. Monitor for abnormally high number of collisions on one port, and yearly perform throughput tests.

  • by slipnslidemaster ( 516759 ) on Tuesday April 21, 2009 @04:58PM (#27666787)
    We replaced all of our Type 1 cabling at my company after the tokens started falling out.
  • Test it... (Score:4, Informative)

    by cnvogel ( 3905 ) <> on Tuesday April 21, 2009 @04:59PM (#27666789) Homepage

    Cables don't get "old" by themselves, but they might have been installed incorrectly from the start (too tight bending, swapped pairs/cables, twisted pairs separated for a longer distance, shields not connected properly, grounding done wrong). Furthermore mechanical stress (too much work being done on a patch panel over the course of several years, cables pulled hard while moving racks, ...) might have damaged parts of the cabling.

    To cut a long story short: Properly done CAT5 should be good enough for Gigabit, but often what's called CAT5 works well for 100 Mbit networks even though it doesn't meet the specs.

    Get a decent LAN tester (not just two computers, using "ping") that prints out attenuation, crosstalk and all the other things... and preferably tells you what "category" your cabling still is compatible with. Replace all the stuff that's out of spec. Then you have hard numbers you can rely on should you ever ponder if your local network infrastructure can handle 100M/1G/10G bit/s. Everything else is guesswork.

  • by Nuriko Yanagi ( 924928 ) on Tuesday April 21, 2009 @05:01PM (#27666817)

    I kind of took this article more to be suggesting that we should be looking at newer data transmission technologies and materials - not so much continuing in a line, all involving copper.

    There are some recent reports released stating that *really* common elements used in technology are about to become exhausted resources - most in the next 10 years, but some as soon as 4 years from now.

    For instance, at our current rate of consumption, Indium will be exhausted in four years. Indium is used for current generation LCD displays, among other things.
    Gold and copper are in the same boat. The US already has closed down most of its gold mines, and all of its copper mines because they're not economically viable to mine for anymore. Predictions put gold and copper at exhausted in around 10 years.
    And none of these projections take into account population growth or new technology demands. It's only at "current consumption rates".

    In other words:

    Should we be looking to upgrade cabling to fiber optics or other mediums for transmission of data, so that we can begin reclaiming copper to be used in more essential capacities?

    • by greyhueofdoubt ( 1159527 ) on Tuesday April 21, 2009 @05:48PM (#27667571) Homepage Journal

      Much like oil, these substances will never truly 'run out'. We're not shooting them out in to space, after all. What does happen is that, like those mines you mentioned, they become too expensive at today's prices. Tomorrow's prices, on the other hand (since demand will rise while the supply drops/becomes more scarce) will make these mines economical once again. Some mines shut down over very small price changes in the metal.

      Copper's price, which was astronomical last summer, has dropped considerably. I know because I bought all the 12/3 cable for my house last summer as a hedge against rising prices and now it costs half what I paid. :(

      And we can always harvest these materials from garbage if the price gets high enough to make it economical.


  • Real question (Score:4, Interesting)

    by Johnny Mnemonic ( 176043 ) <`moc.liamg' `ta' `eromsnidm'> on Tuesday April 21, 2009 @05:15PM (#27667065) Homepage Journal
    "Should I make work for myself on a complicated, invasive, lengthy, and hard to stop project so I can continue to justify my job in a recession?"


    If you're going to do anything, upgrade to fiber.
  • by dyfet ( 154716 ) on Tuesday April 21, 2009 @05:33PM (#27667351) Homepage

    Any category of "cat" can certainly help with that...

  • by Gordonjcp ( 186804 ) on Tuesday April 21, 2009 @05:37PM (#27667415) Homepage

    Over time, UV and ozone in the atmosphere attack the plasticiser in PVC cables. This makes the outer jacket stiff and prone to cracking. Long before the cracks are large enough to be visible, they can be letting surprisingly large amounts of ether escape from your ethernet. Quite often you can regas the cables with a bottle of ether and a special adaptor, but ultimately you will still need to replace them.

  • by gordguide ( 307383 ) on Tuesday April 21, 2009 @08:15PM (#27669391)

    " ... If you are running a 100Mbit/s network on old CAT 5, can that affect performance? ..."
    " ... Do CAT 5(e) cables get old? ..."
    Questions you didn't ask:
    Q: Are old cables bad cables? A: By themselves, no. CAT 5 is made of high quality copper with a PTFE (Teflon) dielectric and protected by a reasonably robust PVC jacket that is rated for in-wall use, a high specification to begin with. They are essentially made of materials selected from the list of the best appropriate materials generally used for any cable need, and better than most of the cable in your home, your car, etc
    Q: Does it degrade slowly over time? A: Yes, in the sense that everything does, and no in the sense that either it's broken or it's not broken.
    Q: How will I know if it's broken? A: It won't work, and that includes intermittently not working.
    Q: Can cables break? A: Yes. If they do, replace or repair them.
    Q: Should I replace my Cat5 cables with Cat6? A: Probably not.
    Q: Is the shininess and newness of my cables the most important part? A: No, the shininess and newness is relatively unimportant. The corrosionlessness and unbrokenness is fairly important, as is the competenceness of the installer, the appropriateness of the grade of original cabling and connectors, and the qualityness of any work by the installer.
    Q: Is it easy to screw up a Cat5/5e/6 installation. A: Yes. Having said all that, CatX cable is remarkably resilient and amazingly tolerant of pathetic, shoddy and downright incompetent installation. Take comfort in that.
    Q: What if I'm not getting the speed I should be from my network? A: Test the cables for integrity, and if you find you need to replace all the cabling, start on page one and decide what to replace it with and what your future needs will be. Keep in mind the goal is "future interconnection" and not "replace the Cat5 with Cat6" (even though that might be the proper conclusion). Whatever your answers, install it all at the same time.

Don't get suckered in by the comments -- they can be terribly misleading. Debug only code. -- Dave Storer