Could a network connection work like a phone jack

Discussion in 'PC Hardware' started by Seymore4Head, Oct 20, 2014.

  1. Seymore4Head

    Seymore4Head Guest

    I have a WDTV and a smart TV. I only have one network connection at
    the location. I really don't need another one, or the current one for
    that matter. Both are also wireless.

    It just made me wonder if the devices could be made with an in/out
    Cat5 port. I say that because I would only be using one or the other
    at any time anyway.

    I do understand that to use both would cut the through put in half,
    but that would probably still be better than wireless.
    Seymore4Head, Oct 20, 2014
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  2. Seymore4Head

    Paul Guest

    You can make network connections directly between devices.
    Even Wifi devices support such a configuration (adhoc).

    When a router assigns IP addresses with DHCP, it does
    it in such a way that the addresses are unique per device.
    One device becomes, the other,
    which would be two non-routable local addresses.

    If you operate two peer level devices, ones where neither
    of them operates a DHCP server, then it is up to the
    user to statically define an IP address. And select
    values which don't conflict with other IP address

    Ethernet cables with RJ45 connectors on the end, come
    as "straight thru" or "crossover" cables. For direct
    computer to computer usage, a crossover cable is used.
    This connects TX on one device to RX on the other,
    and vice versa.

    When Gigabit Ethernet NICs were invented, they were
    given MDI/MDIX capability, and those can automatically
    determine who has a TX, who has an RX, and do the right
    thing on each device. If you have older 10/100BT NICs
    (the slower ones), those don't have MDI/MDIX and they
    only use pins 1,2,3,6. Those four wires is enough for
    two cross-coupled pairs. On the older cables, they might
    only have a total of four wires, arranged as two twisted
    pairs. Modern cables have all eight wires, arranged as four
    pairs. And MDI/MDIX support is a natural part of distinguishing
    between four wire and eight wire usage scenarios.

    Without MDI/MDIX capable NICs, a person ends up stocking
    both straight-thru and crossover type cables, and trying
    them until one of them works. I have a crossover cable
    here, which has a blue connector on one end and a red
    connector on the other end. Which implies crossover.
    If the connectors are the same color on either end, the
    cable is more likely to be straight thru. With a multimeter,
    it is easy to verify the wiring pattern.

    So, to connect your WDTV to your Smart TV *directly* you'd need:

    1) A crossover cable, if they're not MDI/MDIX capable.
    Either type of cable, if they support MDI/MDIX.
    2) An accessible user interface to allow device programming.
    This is easy on the Smart TV, as it has a nice glass screen
    to show the current IP address. The WDTV might need some other
    means of being programmed.
    3) Program static IP addresses in each unit.
    4) Connect the units together.

    Windows devices can use APIPA addresses, which attempt
    to solve the problem without step (2). I don't know the
    details of APIPA on embedded devices like your WDTV and
    your Smart TV. Maybe they'll "just work" when connected

    I would test with the crossover cable first, as it's more
    likely to work in a "direct connect" scenario. But, like when dealing
    with serial ports, you keep all polarities of cables available,
    and you can usually cobble something together that works.

    In some cases, without careful shopping, it can cost as much
    for cabling, as for electronics. I could buy a four port wired
    router for $40, and the four cables I needed to go with it,
    cost $10 each. So the cables cost as much as the (powered
    by wall adapter) router box. One advantage I suppose, of wireless
    devices, is no pricey cables are needed. I bought my cables
    around 9PM at night, from a local retailer, so there was
    no opportunity to acquire a cheaper cable. At $10 each, it
    was "take it or leave it" time. At least they weren't Monster
    branded, or "gold plated". Just ordinary cables.

    With wireless, there is "adhoc mode", but you also have
    the daunting task of getting them to work with one another.

    One benefit of the wired setup, versus the wireless, is
    the wired setup is more secure to abuse from a neighbor or
    someone sitting on the street with a Wifi receiver. The physical
    isolation of wired connections, is one less thing to worry about.


    I'm sure you'll figure something out. One option is going to
    require more "manual reading" than the other. And one option
    is going to cost more than the other, to set up.

    Paul, Oct 20, 2014
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  3. Seymore4Head

    Seymore4Head Guest


    It was just a general question posted in hopes that someone that
    actually worked in the field might think it was a good idea. I rarely
    (never) use the smart TV Internet anyway. If I did I could just
    switch the cable. Just thinking out loud, it would be nice if
    electronics came with an in/out port to enable connection sharing.

    While sharing a connection might not be the most efficient for
    computers, it may be adequate for TVs and such.

    (And I would hope it would work without having to use a crossover.)
    Seymore4Head, Oct 20, 2014
  4. Seymore4Head

    Rodney Pont Guest

    It sounds as if you need a switch. Something like the below. You plug the
    modem into one port and your other devices into the others.
    Rodney Pont, Oct 20, 2014
  5. Seymore4Head

    Seymore4Head Guest

    I actually have a spare one of those. I never use the Internet part
    of the TV any way. It is just I can see a day where every TV location
    could use more than one Internet connection.
    Seymore4Head, Oct 22, 2014
  6. Seymore4Head

    Rodney Pont Guest

    Does that do the sort of thing you are asking about or is it something
    else you want to know? The gig switches sort out there own in/out
    settings and do both ways simultaneously (full duplex), providing you
    have one at each end.
    Rodney Pont, Oct 22, 2014
  7. Seymore4Head

    Rodney Pont Guest

    Should have said I meant a gigabit port at each end, not a gigabit
    switch at each end.
    Rodney Pont, Oct 22, 2014
  8. Well, if you really want to you can wire something like this. The
    error rate on the link will be abysmal but I have seen it function.
    (Some electrician didn't understand how you're supposed to it and
    simply spliced like you would an electric wire. We thought the errors
    on the wire were due to interference and it went undetected for
    Loren Pechtel, Oct 22, 2014
  9. I couldn't imagine streaming working properly over such a setup.

    If you want to make a junction like that you get the tool for the
    job--an ethernet switch. Note that these are powered devices that
    retransmit the signal, not merely splitters. They act as the traffic
    cops of the internet ensuring packets go where they are supposed to
    rather than the collisions that would abound if the wires were simply
    connected together. Connect the wires together and if two systems try
    to talk at once both packets are simply lost. Eventually the
    computers involved realize the packet wasn't delivered but that takes
    Loren Pechtel, Oct 22, 2014
  10. Seymore4Head


    Dec 23, 2019
    Likes Received:
    You have to cable it with the 568B standard, The 4 conductors have to corrospnd correctly and need to be properly terminated
    repairme, Dec 23, 2019
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