Convert RJ12 Telephone Connection to RJ45 Data Connection

Rimus on 09/11/2020 - 05:42
Last edited 09/11/2020 - 10:07

Greetings knowledgeable fellow Ozbargainers!

I've moved into a brand new home recently. In the office room, there was one telephone (RJ12?) socket and one data (Cat5e with Cat6 cable - RJ45) socket wall plate, which connects to a panel in the garage. Since, I don't use a wired telephone connection, I wanted to convert this telephone connection to another data point. When I open the wall plate and checked the cable that connects to the telephone socket is similar to a data cable (blue coloured with 8 core twisted and plastic separation in the middle), which I then assumed is another cat6 cable. I replaced the RJ12 with RJ45 in both locations (office room and in the garage). However, when I connect I couldn't get network connection (internet) through the new data point. Then I purchased a network cable tester from Bunnings and checked the cable. The tester blinks only the 4 & 5, no matter how much I tried securing individual coloured wires to the RJ45. (I followed the same connection pattern as in the adjacent RJ45).

Does this mean, an RJ12 can't be converted to RJ45? OR
There is a disconnection between cable cores within the cable run inside the walls, which I can't trace now?

Any help would be wonderful.

Much appreciate all your responses. I just had a look at the BOM from the builder. It says Cat3 socket with Cat5e cable for the telephone connections. Does this mean anything different to what I've done?

Electrical & Electronics

Comments

  • apsilon on 09/11/2020 - 07:01
    +2

    Assuming you're correct that it's cat6 cable it can definitely be terminated with RJ45. There's s small chance that there's a fault somewhere along the cable (a proper tester will show where) but odds are the problem is with your termination process.

    • Rimus on 09/11/2020 - 09:57

      Thanks apsilon, what do you mean by a proper tester?

      • apsilon on 09/11/2020 - 11:49

        Proper network testers (eg Fluke) will show more than simple connectivity but they cost significantly more than I'd suggest spending for a one off use.

        • Rimus on 09/11/2020 - 13:05

          Thanks mate. I don't think I could justify that much money.

  • RockyRaccoon on 09/11/2020 - 07:38
    +2

    Check using another known Data socket in the house.

    Test one of the exRj12 with say another original RJ45 and see which wires are active

    Test this Original RJ45 with another Original RJ45 and see which are active.

    If all the ex 12's are only registering 4&5 and the Original 45s are showing all 8, then

    Probably there is a junction box (terminal/hub etc) which all the connections run thru and the 12's are only connected there on wires 4&5.

    You would need to find where that box is (Roof, or access panel somewhere) and connect the other 6 wires

    • Rimus on 09/11/2020 - 09:57

      Thanks Rockey,
      I checked the data socket next to the telephone socket, the tester blinks all 8 LEDs in sequence. I don't have anymore RJ12s to check what it would be. I thought that there would be a junction box, but its been a quite short run, garage and study next to each other but sockets are in far end walls, not sure why there would be a junction?

  • Lichen6420 on 09/11/2020 - 07:47
    +1

    If you only changed the plug then you still only have 2 wires connected on the rear.

    The wall plate will need to be re-wired with all 8 wires connected to the rear. You will need a punch tool to get a proper termination and the connection pattern needs to match on both ends. Use pattern A.

    IMO it is fairly unlikely there is a junction box anywhere for data, phone connections unless there is a dedicated data cabinet in the house.

    • apsilon on 09/11/2020 - 08:00

      I'm assuming OP is re terminating the in wall cable to use plug in wall plates rather than a punch block but you could be right, if they're just changing what they're plugging in and not the in wall termination then that's likely the issue.

    • Rimus on 09/11/2020 - 10:00

      Thanks stringbean. I've connected all 8 wires to newly bought clipsal RJ45 socket on both ends (in the office and in the garage). I followed the pattern in the data connection next to the telephone socket, which I believe in pattern B.

      There is no data cabinet.

      • apsilon on 09/11/2020 - 11:47

        There is no data cabinet

        You said earlier it ran back to a panel in the garage. I assumed you meant a data cabinet where all the services etc are located. What panel were you referring to then?

        • Rimus on 09/11/2020 - 13:04

          It is just 6 socket gang plate, 5 data and 1 telephone (previously)

          • apsilon on 09/11/2020 - 15:35

            @Rimus: OK, and you changed it at the garage end as well? Used the exact same order for each of the wires? What's connected at the garage end?

            • Rimus on 09/11/2020 - 15:47

              @apsilon: That's right both ends connected to RJ45s in the same pattern. At garage, the socket is connected to a switch, which is fed from the router.

              • apsilon on 09/11/2020 - 16:21

                @Rimus: Don't suppose it's a really old 100mbit switch? Could run into a problem if you're mixing 568A and B wiring and patch leads but that's a real stretch, I think all that hardware would be dead by now.

                Only thing really left is either one or both of your terminations are bad, there's a join/junction somewhere you don't know about as others have suggested or there's a fault in that cable run.

                • Rimus on 10/11/2020 - 05:59

                  @apsilon: Thanks apsilon. I've got brand new GE108E at the garage connecting all. Other 5 data connections at the garage are terminated with pattern B, hence, I trust there is no mixing.

                  I'm leaning towards having a junction somewhere, which I may not get access due to the office room is in the ground floor.

                  • apsilon on 11/11/2020 - 07:02

                    @Rimus: Just an idea, if you have a spare patch cable and connector. Cut the end off and crimp on a new connector then test it on the known port or between the switch and modem etc. It'll confirm you're terminating them correctly.

                    • Rimus on 11/11/2020 - 10:48

                      @apsilon: When I opened the switch plate in the office room, I didn’t have spare RJ45 socket. So I had to remove two from two room and get them connected, replacing RJ12s in the office and garage. Later I replaced the removed sockets in other rooms. Everything else is working fine. So, I should have done it properly and my termination is good.

  • Yummy on 09/11/2020 - 07:50

    I thought 4 & 5 only used for landlines?

  • foolsgold on 09/11/2020 - 08:09
    +1

    your existing phone line will be wired in a star configuration to other phone points in the house, you would need to disconnect all of these points and get the run to be a single point to point with both sides terminated with a rj45 connector.
    Use the existing cable to maybe pull through another cable when you cant get to.

    • Rimus on 09/11/2020 - 10:05

      Thanks foolsgold. I don't have any other telephone connections. There was one socket in the office room and one in garage, which are not changed to RJ45 with similar patterns to the data points right next to them. The BOM from the builder says (Cat3 socket with Cat5e cable) if that makes any sense to solve the problem.

      • pjetson on 09/11/2020 - 22:48
        +2

        If the cable really is Cat5e as described in the BOM, and the cable definitely runs directly from the office to the garage, then the problem has to be the the way you've connected cable to the RJ45 sockets. Did you use a punchdown tool? Did you use it properly?

        However, as someone else pointed out, pins 4 and 5 are typically used for a phone service. Since those two wires are apparently the only two wires that are connected, it suggests that the Cat5e cable doesn't go directly between the office and the garage - it must go somewhere else along the way, and pins 4 and 5 are the only pins connected at that other place.

        It seems reasonable to me that since this cable is supposed to be a phone connection, that some provision would have been made for a telephone line to be connected to it somewhere, possibly on an outside wall. If that's the case, my guess would be that your cable runs from the office to this connection point, and then on to the garage, and that only pins 4 and 5 are connected at this point. Whoever did the wiring should be able to tell you - ask your home builder.

        Why not just put a small network switch in the office, and run whatever you need over the one network cable that you know works? It'll cost you less than $20 for a five port gigabit switch.

        • Rimus on 10/11/2020 - 05:56

          Hey pjeston, thanks for the response. Yes, I'm leaning towards that there is some sort of junction in between the office room and the garage. Being two story house and office room in the ground, I may not have access to this 'junction'.

          I've used punchdown tool and trust used it properly. As I had to relocate the wall plate at the office room, I had to disconnect the data socket and reconnected it, which is working well. So, I must have done it properly.

          I could have used a switch. However, my target was to connect the printer separate to office room pc and leave office pc out of the other internet connected devices. I've got a manage switch (Netgear GS108E) at the garage that will give me VLANs to separate two networks.

          BTW, I'm totally new to networking stuff, learning as I go.

  • abb on 10/11/2020 - 15:34

    Post a photo of your terminations at each socket. Chances are you did it wrong (don't worry, I've seen plenty of electricians with years of experience do it wrong too!)

    edit: re-read and saw you suspect a junction somewhere - very possible. Have you identified where the telephone cable from the street connects into your old wiring?

    • Rimus on 10/11/2020 - 16:39

      Thanks abb for the reply.

      I don’t have street connection as it is NBN. I got NBN box and socket panel next to it. The panel had 5 data sockets and 1 telephone socket, which I replaced with RJ45.

      • abb on 10/11/2020 - 20:22

        The telephone cabling was once connected to a telephone line from the street though, right?

        • Rimus on 10/11/2020 - 21:17

          No. New build. No PSTN line. Only NBN.

          • abb on 11/11/2020 - 10:16

            @Rimus: Ahh, right. That makes a hidden junction less likely.

            • Rimus on 11/11/2020 - 10:45

              @abb: You think so? Then it is a quiet mystery why I only detects 4&5?

              • abb on 11/11/2020 - 11:42

                @Rimus: Less likely, but not impossible ;)

                I don't know why the installer would put a junction in a point to point cable though, if there are no other phone sockets in the house.

                Send us a pic of your terminations at both ends?

                If the terminations are good, and there's no defect in the socket, you're going to have to physically trace out the cable looking for a join. Do you have a multimeter? If so, you can short a pair at one end and measure continuity at the other end, to bypass any possible (unlikely) defect in the socket itself.

                edit: have you verified your cable tester's operation on one of the working cable runs?

  • pjetson on 10/11/2020 - 22:41

    I know it sounds like a silly question, but are you sure that there's not another telephone point somewhere in the house?

    • Rimus on 11/11/2020 - 06:46

      Definitely not :)

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