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Thread: RJ 45 Splitters?

  1. #1

    RJ 45 Splitters?

    Was wondering if there is such a thing as an RJ 45 splitter? I have a PC I was hoping I could share on the same ehernet cable and split it off without having to buy another hub.

    Anybody heard of such a thing?

  2. #2
    Senior Member
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    Nope. Impossible...

    Ethernet isn't like phone transmissions: phone is analog (using voltage or amplitude, which one I don't konw); when you speak on the phone, your voice modifies the wave. If someone else talks at the same time, both waves combine... This is possible because it's an analog signal.

    Ethernet on the other hand is a digital signal. To represent the signals 0 and 1, analog encoding is used (manchester differential if I remember right), but combining to signals would result in a signal totaly meaningless...

    So no it is (unfortunately?) not possible...

    Small hubs are pretty cheap nowadays though...

    Ammo
    Credit travels up, blame travels down -- The Boss

  3. #3
    Jaded Network Admin nebulus200's Avatar
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    Well, it might be possible to split RJ45 since two of the pairs are not used; however, I am not sure what effect that would have if you start using the other pair, and whatever you do on one end you would have to do on the other. While probably possible, I would recommend just running another cable and using a hub/switch, that way your results are garunteed.

    /nebulus
    There is only one constant, one universal, it is the only real truth: causality. Action. Reaction. Cause and effect...There is no escape from it, we are forever slaves to it. Our only hope, our only peace is to understand it, to understand the 'why'. 'Why' is what separates us from them, you from me. 'Why' is the only real social power, without it you are powerless.

    (Merovingian - Matrix Reloaded)

  4. #4
    I figured it was not possible. I'll have to buy another hub. Thanks fellas...

  5. #5
    Jaded Network Admin nebulus200's Avatar
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    Did a google search after looking at your response and it does appear possible:

    http://www.mycableshop.com/sku/RJ45SPLITTER.htm

    Although found their description fitting:
    Our RJ45SPLITTER increases the number of RJ45 network connections on an RJ45 outlet.
    Increases the number of RJ45 network connections on an RJ45 outlet

    Must have a second RJ45SPLITTER or RJ45COMBINER at opposite end of line

    Cannot be used to share a single network line with two computers - use a hub instead

    Example: Use an RJ45SPLITTER to combine two cables into one RJ45 wall outlet, and an RJ45SPLITTER at the other outlet to split one line back to two

    Connectors: RJ45 Male, 2x RJ45 Female
    /nebulus
    There is only one constant, one universal, it is the only real truth: causality. Action. Reaction. Cause and effect...There is no escape from it, we are forever slaves to it. Our only hope, our only peace is to understand it, to understand the 'why'. 'Why' is what separates us from them, you from me. 'Why' is the only real social power, without it you are powerless.

    (Merovingian - Matrix Reloaded)

  6. #6
    Senior Member SodaMoca5's Avatar
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    Not only possible it is easy it is also not recommended. There are two methods, if you want to create two distinct cables from one you can do the following.

    How you do this will depend upon if you are going to use a punch down block or just connectorize the ends.

    To make this easy I will label the punch downs as 1-8 and the pins as 1-8. Please note the pairs are: Pair 1 = Pins 1,2 Pair 2=Pins 4,5 Pair 3= Pins 3,6 Pair 4=Pins 7,8 This is the standard RJ-45 pair-outs

    PUNCHDOWN BLOCK

    Pair 1/Port 1 on Block to Pair 1/RJ-45 1 (Orange White to 1, Orange to 2)
    Pair 3/Port 1 on Block to Pair 2/RJ-45 3 (Green to Pin 3, Green White to pin 6)
    Pair 1/Port 2 on Block to Pair 1/RJ-45 1 (Blue White to 1, Blue to 2)
    Pair 3/Port 2 on Block to Pair 3/RJ-45 3 (Brown to 3, Brown white to 6)

    Now on the connection side you will have to connect pair one and pair three from the jumper going to the network connection so it is punched down (without severing the extra) to each of the ports on the blocks being used. So with the two illustrated you would punch the orange white cable to Pair 1/Port 1/Punch1 and then loop it over and punch it to Pair1/Port 2/Punch 1 as well. Continue this with the other three from Pairs 1 and 3 and you have created a two port mini hub and split one cable into two.

    You can create more ports easily by just punching down extra cables without splitting the cable (which is pretty useless unless the dual ports are very close together). Just punch down the 1/3 pairs to the punchdown block (use a 66 block since they are cheaper and you are not following CAT 5 standard anyway). Then loop the 1/3 pair cable from the network connection through the multiple ports.

    This makes a hub but note it is unpowered and is therefore not operating as a repeater which most hubs do. Also this is acceptable by CAT 3 standards which guarantees up to 10 Mbps transfer but not by CAT 5 standard.

    THE CHEAP MANS HUB

    You can make your own hub very easily without even a punchdown block. Put a one end jumper into you network connection and leave the wire bare at the other end. Take how ever many "ports" you want with each port being another single ended jumper cable. Now twist and connect each of the Orange Wires with the Hub Orange, Orange White with Orange White etc. Make sure the connections are good and you have an unpowered hub with no repeating capability.

    This will work as long as you are using Ethernet since it is a CSMAC/CD collison detection transmission protocol. However the max length from computer to internet connection cannot go over 100 m. nor from computer to computer.

    Final statement: This is possible, this is not recommended. It is like the cheap stereo setups a lot of people used to put in cars. They played music until bumped or jostled or whatever. This type of setup is inherently flawed. Especially when a 5 port switch with an uplink port costs $50-$80. So while it can be done, IMO, it should not be done. However if you really love wasting your time troubleshooting network physical layer errors, just set up you network the way I have described.
    SodaMoca5
    \"We are pressing through the sphincter of assholiness\"

  7. #7
    try this radio shack has a nifty little gadget that does work
    http://www.radioshack.com/product.as...5Fid=278%2D785

    a link to the schematic http://support.tandy.com/support_sup...oc66/66324.pdf

    it's shack part number 278-785

    just thought I'd throw in my .02 but in reality you can get a 4-5 port 10mb hub for a few dollars more.

  8. #8
    Junior Member
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    or you could buy 2 ethernet cards and use a crossover cable ( use one pc as the gate way with two ethernet cards) prob just as cheap going for the hub

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