long cables and domestic routers

Discussion in 'Home Networking' started by tg, Jun 13, 2012.

  1. tg

    tg Guest

    I've made a network cable using a long cat5 cable and two Videk cat5
    faceplates but I can't get a network connection. I tested the cable end to
    end with a network cable tester and all the lights show up perfect. The
    cable is long-ish (70 - 80 meters) and one end connects to a netgear DG834G
    router. The other end is connected to a netgear fs516 hub. When I plug the
    cable into the router the LAN light flashes on and off rythmically about
    every three seconds. The same happens with the light on the netgear hub. The
    netgear DG834G router is just a domestic/home router.
    Do these routers have a limitation when using long cables? Could anyone
    recommend a decent booster? I don't think the wiring is at fault because the
    tester showed all fine.
    ....scratching my head here so thanks for any pointers.
    tg, Jun 13, 2012
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  2. tg

    Will Guest

    Spec for cat5 is c.100m. so no problems there (for proper cat5).
    You have a cable/termination fault and I suspect your cable tester is only checking continuity.
    Look up EIA 568B for details.
    Will, Jun 14, 2012
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  3. tg

    tg Guest

    Spec for cat5 is c.100m. so no problems there (for proper cat5).
    thanks for your response.
    I searched on EIA 568B but only found data for the RJ45 plug, not the
    module. Is the colour coding the same at both ends for modules? or should
    one end be A and the other B? when I wired the modules I did both ends the
    same as this:
    but it's not working. This is the first time I've ever installed cat5
    tg, Jun 14, 2012
  4. tg

    John Weston Guest

    Therein lies your problem - that diagram applies to one
    manufacturer's type of socket wiring only and would
    incorrectly terminate two of the pairs for some other types.
    A simple LED continuity tester may not show this as an error
    if you've wired both ends the same.

    Most UK sourced wall sockets I've used have a small printed
    circuit board (PCB) onto which the socket and punch-down
    block (PDB) are soldered. This PCB also deals with the non-
    adjacent receive (Rx) pair on pins 3 & 6, allowing the cable
    pair carrying this signal to be wired to adjacent pins on
    the PDB. As an example, one from my wiring case, from
    Solwise, I think, has two 4-way punch-down blocks that,
    according to the attached wiring diagram should be wired
    G/GW, BnW/Bn, BW/B & OW/O from top left to bottom right,
    with the RJ45 socket below the PDB. The PCB does the
    connection from these PDB pins to pins 6/3, 7/8, 5/4 & 1/2
    on the RJ45 socket respectively.

    You should wire your fixed house cabling "straight" (1-1,
    2-2, 3-3, 4-4, 5-5, 6-6, 7-7, 8-8) rather than "cross-over"
    (1-3, 2-6, 3-1, 4-4, 5-5, 6-2, 7-7, 8-7). Cross-over is
    only used for 10/100 jumper cables and are largely redundant
    these days since the latest Ethernet ICs can detect when
    they need the cross-over and do the necessary internally.
    You should also use solid-core cable, not stranded (the PDB
    blade spacing is designed for solid, not stranded wire)

    If you first throw away your handymanhowto.com
    misinformation (!! - my AV checker doesn't like this site
    either :eek:)) you can verify your wiring with a continuity
    tester a wire at a time to check you have one pair (Tx)
    going to 1 and 2 and another (Rx) going to 3 and 6. The
    other two pairs are only used for 1000Mb Ethernet and some
    other applications.

    Hope this helps
    John Weston, Jun 14, 2012
  5. tg

    Dave Saville Guest

    The same both ends. Be aware that there are several ways of wireing
    RJ45 depending on the protocol it is expected to carry. The tester
    needs to know which - or be one specifically for ethernet.

    It also depends on the type of cable - solid or stranded copper. To go
    into krone connectors you need solid - so the teeth bite and get a
    good connection. To go into RJ45 plugs you need stranded - so the pins
    penetrate the strands when you crimp the plug. Plus you have a better
    bendy patch cable the stranded being more flexable. The two types are
    not really interchangable but you may get away with it sometimes.

    Dave Saville, Jun 14, 2012
  6. tg

    Will Guest

    Not quite accurate. Use solid cable with plugs for solid cable and more flexible, stranded cable with plus for stranded
    (multi-strand) cable. If the pack doesn't say, then assume they don't know and stay well away from. Using the wrong plugs often
    ends in tears and at best will work 'for now' only.

    The most important thing to understand about the wiring (568B) is to stick to one throughout. I prefer to stick to one everywhere
    in life but appreciate some people have already wired to 568A so I accomodate it where needs must. Use (A) or B but only one. Of
    course a patch lead in A will work fine in B it is only the colours that have swapped and the electrons are effecively colour
    blind anyway.
    Next thing to spot is the pairing, where you've most likely gone wrong, the 8 pins are not in straight pairs and it is the 'pairs'
    that keep the cabling balanced and the crosstalk at bay.
    Will, Jun 17, 2012
  7. tg

    robert Guest

    50 & 60m pre-made RJ45 patch cables are readily available and reasonably
    priced <£10.
    Unless you are trying to thread the cable through holes they are IMHO an
    easy option if long enough !
    robert, Jun 17, 2012
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