Phone cable and networking

Discussion in 'Broadband' started by Vir Campestris, Jun 14, 2014.

  1. Not _strictly_ telecom, but I'm sure people here will know...

    I struggle with 'net our here in my shed, using wifi back to the house.
    I get 5 megs on a good day, and dropouts on a bad one. Running an
    Ethernet across is on my list... (along with re-roofing the house, so
    you'll realise net is a little down the list) but I've just realised the
    PO had 'phone out here, so there's an armoured phone cable connecting
    back to the house. I didn't count, but I'd guess 16 pairs or so.

    Would it carry Ethernet? I don't need much speed - 10 megs is fine. Or
    do I need to bring the 'phone signal out here instead?

    It's about 15-20 metres.

    Vir Campestris, Jun 14, 2014
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  2. Vir Campestris

    Dave Saville Guest

    Hmm I don't think there will be enough twists/metre in phone cable for
    ethernet to work well

    I assume the wifi router is in the house and you are just using a

    Get an AP that works as a *client* and then cable all connections in
    the shed. ie use the AP as a switch. That way you can put the AP in
    the best reception spot and put some sort of reflecter in place to
    enhance the signal. You could also do that at the house end but that
    will restrict coverage in the rest of the house.

    Dave Saville, Jun 14, 2014
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  3. Vir Campestris

    Graham J Guest

    Do you need internet in the house? If not then extend the unfiltered
    phone service to the shed and put the router there.

    Occasional internet requirement in the house could be met by WiFi.

    Alternatively (but fairly expensive) terminate the best twisted 4 pairs
    of the phone bundle in RJ45 connectors, and put a managed switch at each
    end. You can then examine the performance of the link; it might be

    You might be able to configure the switches to use 100BASE-T4 over this

    Managed 8-port switches start at a bit over £100
    Graham J, Jun 14, 2014
  4. Vir Campestris

    Tweed Guest

    Is the shed on the same meter and mains phase as the house? If yes, power
    line aka home plug might be a way forwards. Might be worth trying to borrow
    a pair of plugs before investing.
    Tweed, Jun 14, 2014
  5. Vir Campestris

    NY Guest

    Just a thought: is it the outside of the phone cable that's armoured or is
    it in an armoured conduit? If the latter, could you pull out the phone cable
    and poke Cat5 cable down there instead?

    You say that you get 5 Mbps on a good day? I presume that's wifi back to the
    router and that the ADSL is faster - eg for computers within the house
    connected by Ethernet? Do you need fast comms between the shed and other
    computers (eg to access shares on the house computers from the laptop) or is
    most of the laptop use for accessing the internet? In other words, how
    important is it to get the shed comms faster than 5 Mbps - as long as that
    speed is consistent and not just "on a good day".
    NY, Jun 14, 2014
  6. It might work for ethernet; you've got nothing to lose by trying if
    the cable is already there, but I would definitely *not* recommend
    using it as an unfiltered phone extension and putting the modem/router
    in the shed, as this may reduce the data rate. You should seek to
    minimise the length of cable which is carrying ADSL.

    Pending running proper ethernet cable to the shed (which is the right
    way of course), you could try to improve the wi-fi link by running
    ethernet within the house to another access point which has a better
    line-of-sight view of the shed, perhaps on a windowledge, and you
    might also put a bridge in the window of the shed if there's one
    facing the house. The Edimax 7228, for example, can be configured both
    as an access point and a bridge, so a pair of those would do it. I've
    also seen designs for homebrew cardboard and foil reflectors which can
    apparently help quite a lot, though I haven't needed them in my setup
    so can't speak from experience here.

    Roderick Stewart, Jun 14, 2014
  7. Vir Campestris

    NY Guest

    Check also that the glass in the windows doesn't have a heat-reflective
    coating, as this can attenuate a wifi signal. And check that the walls of
    the shed (eg internal plasterboard lining) don't have a foil coating - this
    really does attenuate the signal. I encountered both these factors when
    trying to get wifi to a shed that was being used as an office from a new
    house with fancy energy-efficient (coated) glass. With direct line of sight
    over about 10 m, the signal strength reported by one of the computers was
    pathetic, and it was due to coated glass, foil plasterboard and rubber-duck
    aerial on PCI card being in the shadow of the PC's case.

    The other enemy of wifi is water tanks - firstly because they are metal
    (certainly true for copper hot-water cylinders) and secondly because the
    wifi signal is absorbed by water - I believe it is only available for
    short-range wifi because its frequency matches a resonant frequency of the
    water molecule, rendering it useless for long distance broadcasts if there
    is falling rain, clouds or mist in the way. This might affect reception
    within the house once you've got the router in the best position for
    communicating with the shed.
    NY, Jun 14, 2014
  8. Vir Campestris

    Woody Guest

    Woody, Jun 14, 2014
  9. Vir Campestris

    Graham. Guest

    Well worth a try, I have successfully done this on several occasions.

    You only need two pairs, pins 1&2 and pins 3&6 corresponding to the
    orange and green pairs on the RJ45 connectors.
    Graham., Jun 14, 2014
  10. Vir Campestris

    Graham. Guest

    The way I look at it, the ADSL has probably come several thousand
    meters underground in a bundle of pairs intended for audio, with
    adjacent pairs carrying various flavours of DSL, ISDN, pair gain
    digital protocols, and the occasional line ringing an old inductive
    bell, or phone still using spiky DP dialling.

    Add to this the fact that the cable may run close to ducts carrying
    3ph electricity cables not to mention sodium vapour street lights and
    a host of other electrical street furniture.

    Is a further 20m of bad practice likely to make a measurable
    Graham., Jun 14, 2014
  11. Vir Campestris

    Roger Mills Guest

    +1 (Assuming there's mains in the shed, of course!)

    Even if you have a separate consumer unit in the shed, it will likely
    work between house and shed - it does between my house and garage, with
    a similar setup.
    Please reply to Newsgroup. Whilst email address is valid, it is seldom
    Roger Mills, Jun 14, 2014
  12. Vir Campestris

    Roger Mills Guest

    Why? The ADSL has probably already come 1 or 2 Km from the exchange.
    What's another 20 metres between friends?
    Please reply to Newsgroup. Whilst email address is valid, it is seldom
    Roger Mills, Jun 14, 2014
  13. Yes. It's not just the length, but the mismatch between different
    types of cable that can cause problems, and posibly proximity to other
    cables. RF isn't like hi-fi. There isn't always a problem, but best
    practice is generally the least complicated route with the smallest
    number of joins, and sometimes it does make a measureable difference.

    My recommendation would be to put the modem as close as it can neatly
    be accommodated to where the phone cable enters the house, and extend
    the local network as necessary, rather than extending the unfiltered
    phone cable.

    Roderick Stewart, Jun 14, 2014
  14. Vir Campestris

    Andy Burns Guest

    I've used 10Mbps ethernet over cat3 (phone) cabling, at a distance of
    about 50 metres (works very reliably, just as well because it's a direct
    heartbeat connection between two nodes in a cluster in different
    buildings - we didn't want the heartbeat to depend on the fibre switches
    between the buildings).
    Andy Burns, Jun 14, 2014
  15. It depends on what sort of cable the 20 metres is made of, how well
    it's connected, what other unrelated equipment it's connected to, and
    where it's routed in relation to other cables carrying other signals.
    It doesn't always make a difference, but it can. The best arrangement
    for an incoming cable carrying RF is the simplest one - straight into
    the modem and nowhere else.

    Roderick Stewart, Jun 15, 2014
  16. Vir Campestris

    Graham J Guest

    We're talking here about the ideal arrangement versus what might work.

    Extending the unfiltered phone signal a further 20 metres could well
    work. However you won't know until you try it.

    The router will give you a good indication; compare the line performance
    (SNR margin, loop loss, and sync speed) where it is in the ideal
    arrangement (which we assume to be directly adjacent to the BT master
    socket in the house, via a faceplate microfilter, with no extension
    wiring or phones connected) - compare this with connecting it on the end
    of the proposed extension into the garden shed.

    The cost of trying this is minimal: fit RJ45 connectors onto the phone
    cable running to the shed, patch from the house end to the ADSL output
    of the faceplate microfilter (yes, a RJ45 plug will go into this socket)
    and improvise a connection from the RJ45 connector in the shed to the
    RJ-11 connector on the router. This last bit may be a challenge; some
    RJ-11 to RJ-11 leads that come with fax modems will have the correct
    pinout - otherwise cut the RJ45 connector off a short patch lead and
    connect the cut end into a standard BT phone socket - the BT-to-RJ11
    cable that came with the router will then work.

    If the router now reports similar performance then you have an
    acceptable arrangement; if not, the exension cable can be tested
    carrying Ethernet - you have already prepared it with the RJ45 connectors.

    As suggested in my earlier post, managed switches each end will show you
    how well this cable behaves. Without them you won't have any easy way
    of evaluating performance.
    Graham J, Jun 15, 2014
  17. Very true. I still think the most elegant solution is to extend the
    local network rather than extend phone cables that were never intended
    for shortwave frequency RF, and that's what I'd normally plan for, but
    if there is an easily accessible cable already in place, there's
    nothing to be lost by trying to see whatever works.

    Roderick Stewart, Jun 15, 2014
  18. Vir Campestris

    Andy Burns Guest

    Andy Burns, Jun 15, 2014
  19. Vir Campestris

    Woody Guest

    It may of may not.

    As I sit here typing the modem (we are on cable) is about
    10ft away in the next room. I decided I wanted a fixed
    connection rather than wireless so bought a pair of home
    plugs and tried it out. Zilch. There is only about 12ft of
    cable and three sockets involved, but the electricity meter
    in the garage below sits between my socket and the next and
    that clearly adds so much impedence loading that it soaks up
    the RF. Plug the unit in to the socket on the the other side
    of the room/meter and it works a treat.

    In the end I got some very thin flat RJ45 which I was able
    to push down the edge of the carpet against the skirting.
    Woody, Jun 15, 2014
  20. What did you do to avoid bridging two different earth domains and/or
    phases with your Cat3 and Ethernet switches?
    Rupert Moss-Eccardt, Jun 15, 2014
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