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I'm trying to add a RJ45 connector to a Ethernet cable for a NVR system (Surveillance Cameras).

The cameras comes with ethernet cables and I see that the only have 4 cables used and in different positions than RJ45 color coding T568A or T568B (image below)

Seeing from bottom, the order is White Orange,Orange, Blue White, None, None, Blue, None, None.

I know that some question should be answered by the manufacturer, but in theory, the cameras should work with standard T568A/B?

Is this another standard?

since I tried this ethernet cable connecting a laptop with a router and internet connection it works. So, it seems the missing cable colors are not needed for the cameras nor internet connection.

Thanks in advance.

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Rasec Malkic
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    Are they actually IP cameras? RJ45 connectors and cables are inexpensive to integrate into systems that may not be Ethernet and so are often used. Typically, the manufacturer will provide custom cables when this is the case. – music2myear Jul 16 '23 at 00:09
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    All T1236 is doing is cutting the bandwidth of the cable in half basically splitting it. They are needed if you want full 1/10/100GB speeds instead of 10/100MB – Ramhound Jul 16 '23 at 00:48
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    @music2myear: Yup. My employer uses a Cat. 5 cable with RJ45 connectors for the internal connection between the headphone amp inside one of our devices and the headphone jack in the case, for example. – Jörg W Mittag Jul 16 '23 at 11:24
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    Your cameras are clearly not POE powered if that's the cable used. Might be worth checking if they can be powered over the ethernet, if you used good 4pair cabling. – Criggie Jul 16 '23 at 12:52
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    @Criggie Yes, you´re right. It I connect 4 pair cable the cameras work. And since they don´t have any power cable, are powered over the ethernet. – Rasec Malkic Jul 17 '23 at 04:56
  • https://superuser.com/questions/701273/what-would-be-the-disadvantages-of-using-a-4-stranded-ethernet-cable I've seen these in the wild too. .... Interestingly mine used the 'same' connectors but used green instead – Journeyman Geek Jul 17 '23 at 11:59
  • Note: for clarity, it helps to refer to the entire jacketed assembly as a *cable* and the constituent color-coded insulated conductors as *wires*. Each set of two wires with the same main color are called a *pair*. As in, "the cable that came with the camera only has four wires in it - the orange pair and the blue pair. The green and brown pairs of wires are not present." Using terms this way would help with talking about "cables with only four cables". – Todd Wilcox Jul 18 '23 at 19:45

3 Answers3

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This was how Cat3 (voice grade) cables were sometimes wired for 10BASE-T (old 10 Mbps Ethernet from the 80's and 90's). It only has the two pairs necessary for 10BASE-T. It's probably not Cat5 quality cable or better, but if it were, it would meet the requirements for 100BASE-T (100 Mbps "Fast Ethernet" from the late 90's), because that used just two pairs in these two locations, but it required Cat5 or better. These cables will not work for 1000BASE-T (1Gbps "gigabit Ethernet"), because gigabit Ethernet requires all 4 pairs.

You can replace these cables with proper 4-pair Cat5e T568A or B cables and your cameras will work fine; the placement of the two necessary pairs is the same on a modern cable as they are in the cables you got with your cameras.

Spiff
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You're focusing on the colour - instead consider the signal on that wire.

Minimum RJ45 Pinout for a 10/100 Mbit LAN Cable
Pin 1 → Transmit +
Pin 2 → Transmit -
Pin 3 → Receive +
Pin 4 → 
Pin 5 → 
Pin 6 → Receive -
Pin 7 → 
Pin 8 →

The electrons don't care what the colour of their wire insulation is.

The only reason we have specific pairs allocated is because this reduces cross-talk between adjacent pairs. By twisting both legs of Transmit together, any stray noise induced in one wire is likely to be induced in the other wire the same way, raising/lowering both voltages by the same amount and leaving the same nett difference.

For short runs it is possible to use flat cable without any twists, though that's often well under a metre before the signal becomes degraded.

There's also a very small minor advantage that the Blue pair is in the middle, which is where Telco wiring would expect to find an analogue voice pair, and Telecom-types would number the Blue/white pair as the "first line" so having it not used by 10/100 Mbit could prevent damage if something was misplugged.

And yes, this means it is totally possible to run two separate 100 Mbit links over a single 4-pair cable - in the early 2000's I did it where there was only one run of wiring installed but we needed exactly two hosts, and a small desktop switch was not justified.

Criggie
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In the Bell color scheme that 568A and 568B both use a subset of, pair 1 is blue/white, and pair 2 is orange/white. So the diagram illustrates the correct way to wire the connector for any cable that only has two pairs. Or, really, any cable that has at least two pairs, since the colors don't matter, so long as pairs are paired up correctly.

hobbs
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