Network cable: Assignment of wires and pins for Ethernet

Cable in the network, short Network cable, their assignment, this and that standard for pins and wires, the difference between Token Ring and Ethernet, what has to be considered with connectors and cabling, and much more - that will be the subject of this article. I would like to introduce you to the mentioned and related areas for network cable assignment and give you a few insights. In addition, I will give you sources for the corresponding further training. Because to really list all the comprehensive details here would go beyond the scope ... and only the worst nerds among you would read the article in full;)

Network cable assignment including cable color and pin usage
Networks and Internet via LAN cables with RJ45 plugs have become the norm - but what does the network cable assignment, including cable color and pin usage, look like in detail?

Standard in Europe and the world

Perhaps you have come across the names EIA / TIA-568A, EIA / TIA-568B and 258A. The last two mean the same standard of cables for Ethernet with RJ45 plugs. However, the color assignment for the individual wires or wire pairs is regulated differently. In the following I want to show you very brief details about the standards and then the individual color combinations in a table.

  • EIA / TIA-568A: Mainly used in Europe because the color coding is the same as that of telephone cables
  • EIA / TIA-568B: Formerly the 258A standard from the American provider AT&T, also applies to RJ45 plugs, but the wire colors are different; outside of Europe this assignment is used

And here is the corresponding table (briefly noted: the colors are different; how the individual cables, pins and wires are used depends on the connected elements):

Pin Color (568A) Color (568B)
1 White / green White / orange
2 Green white Orange / white
3 White / orange White / green
4 Blue White Blue White
5 White blue White blue
6 Orange / white Green white
7 White Brown White Brown
8 Brown / white Brown / white

Representation as graphics

Here I have picked out two graphics for you, which show the network cable assignment and the allocation of the individual pins for the two standards. The source is SearchNetworking.de; you can find the exact link below:

Pin assignment and color / color pairs for EIA / TIA-568A.
Pin assignment and color / color pairs for EIA / TIA-568B.

Assignment of the pins on the network connector

Now we already know how colorful the network cables are on the inside and why there are two standards. To use a cable, you also need plugs and corresponding sockets. The communication between the two parts is realized through contacts - a contact is called a pin. The network connector RJ45 has 8 pins, as shown in the table.

The pin assignment is different, depending on the networking technology (Token Ring or Ethernet), use as a telephone, ISDN, DSL, Ethernet or other transmission option. Here is a small table with individual assignments. The source is at the end of the article:

Pin Analog telephone (internat.) Analog telephone (Siemens) Analog telephone (Telekom) DSL

Splitter

Token ring Ethernet Gigabit Ethernet
1 TX + D1 +
2 TX D1-
3 E W b RX + RX + D2 +
4 a a E a TX D3 +
5 b b W b TX + D3-
6 W E a RX RX D2-
7 D4 +
8 D4-

Legend: a and b = A and B wires; E = ground; W = alarm clock; RX = Receiver Exchange; TX = transmitter exchange; + and - indicate the direction

Token Ring and Ethernet

In addition to color pairs, pin assignments and the like, the terms Token Ring (TR) and Ethernet have come up several times. Regardless of the cable in the network, there are two networking techniques, of which TR is the older. Ethernet has largely replaced them with regard to LAN connections, i.e. networks via cable. Here are a few brief pieces of information:

  • Token Ring: developed in the 1980s; Data packets rotate under the nodes; Computers request data, receive them in turn, check and confirm addressing and receipt
  • Ethernet: emerges from local networks (LAN connections); Data exchange is based on data paths (cable pairs for there and back) without rotating data packets

Useful links on this page

Sources for this article (click for more info)

Any questions?

Do you have any questions or do you want to know more about networks, network cables, pins, color pairs, plugs, sheathing and Co.? Then leave a comment or your question under this post!

Did you like the article and did the instructions on the blog help you? Then I would be happy if you the blog via a Steady Membership would support.

17 comments on "Network cable: Allocation of cores and pins in Ethernet"

  1. The question is only partly part of the topic:
    I have an Apple TV 2 with which I can stream music and videos (films) that are stored in iTunes on the PC to my TV via WiFi. I would now like to connect an external hard drive, which is defined as NAS, to my Fritz! Box 6490 Cable via USB. What do I have to do to access the music and video data on this external hard drive (NAS) from the Apple TV 2 without having to switch on my PC? Does iTunes have to be installed on this external hard drive and the music and video files or just the music and video files?
    Maybe someone has already had experience with it and / or knows how it works?

    1. Hello Horst! Unfortunately, this does not work with an Apple TV 2nd GEN. With the current version, you have the option of installing apps on the Apple TV. And there you can, for example, install VLC (Video Lan Client) and use it to access the hard drive on the Fritz! Box. Since the hard drive is not your own Mac and has no operating system, you cannot run iTunes on it. At most, you could use an old Mac to play an external disk of movies on the Apple TV via library sharing. I'm sorry I haven't got any positive news. :-( LG! Jens

  2. Dear Sir Apfelot,
    only red cables come out of the wall! Two blank, two with a black stripe, two with double black stripes and two with lots of double black stripes. Do you know anything about this?
    Hopeful greetings

    1. Hello handyman! These are the old telephone cables, if I'm not mistaken. What is your plan? To connect the router?

  3. Hello, Jens!
    Thank you for your prompt reply!!
    The router is in the attic and is already connected to a network socket. Vodafone has been connected in the basement. Since the WLAN is relatively bad everywhere in the house, I would like to install a network socket in every room. The connections for this are available, but apparently with the old telephone cables, for which I can hardly find any information on the occupancy. I have now discovered that these are 2 J-YH cables with 4 wires each.
    So far we have used such Devolo plugs, but they keep failing.
    The plan is to operate all devices locally via LAN cables if required. For the devices that need WLAN, a small router should possibly be connected to the socket in the respective room.

    1. Hello handyman! What speaks against creating a mesh network through home? Then you save the hassle with the old telephone cables ...

  4. Hello Sir Apfelot, I wired the wires blue / white for my DSL connection.
    As far as I know, I can continue the internet connection from the DSL router with the others (this is only possible because the cables were already laid). It doesn't matter which 6 they are. Your explanation says that you need green / white and orange / white for Ethernet. So can I use these and the brown / white to set up an internet connection (clearly with reduced transmission). Many greetings, Sven

    1. Hello Sven!

      Maybe I'm getting something wrong, but that sounds to me, so you want to extend the network cable like you can do with power cables. But since each device needs its own port on the hub, this is not so easy. Or I misunderstood you completely. : D Then I apologize in advance. : D

      1. Hi Jens,
        thank you for the first feedback. I don't think I explained it well enough. For me it is the case that an 8-core twisted pair cable comes into the house. There is also a central distribution point for cables, but the DSL box cannot be located there. The previous owner then laid another 8-pin cable to the location of the DSL box and used blue / white for the DSL box via TAE cable.
        I would now like to have wired internet somewhere else in the house and therefore have to go back to this central distribution point. I would like to use the other 6 wires for this. In the meantime I've tried it and it works like this. Thank you again for your feedback. Many greetings
        Sven

        1. Hello Sven! Thank you for your feedback signal. I actually didn't understand that. But I wouldn't have had any experience. : D But thank you for describing again how you have now implemented it. Maybe it will help one or the other reader.

  5. Hello Sir Apfelot

    The topic of the gigantic network and the various standards. I have the standard assignment of an 8-pin X-coded Giga line. But now I have to connect a participant who needs an 8 pin A coded data connector. Now the question is, how does the A coded data connector on the data line have to be connected to the X coded connector on the other end?
    X coded 1 white / orange to 6 D coded
    X coded 2 orange to 4 D coded
    X coded 3 white / green to 5 D coded
    X coded 4 green to 8 D coded
    X coded 5 white / brown to 8 D coded
    X coded 6 brown to 3 D coded
    X coded 7 white / blue to 1 D coded
    X coded 8 blue to 7 D coded

    Can it be like that?

    1. Hello Wolfgang! Unfortunately I can't help you there. Johannes wrote the article in 2017 and unfortunately I have no background information that would help with your problem. But if you can still find out what the allocation should be for your problem, then I would be happy to hear from you!

  6. Hallo,
    my router is in the attic and I would like to lay a LAN connection via a cable for an Internet connection in the basement. A 15-core cable is already in place. I would like to install 2 LAN sockets, one in the attic and one in the basement. My idea: connect a LAN cable from the router to the socket in the attic and connect it to the socket in the basement using the shielded cable. Do I only need to connect Pin1 to Pin1, etc. with the cable, or do they have to be connected crosswise in some way?

    1. Hello three! As far as I know they are connected 1:1. Cores are only swapped with a crossover cable. But not with a connection from socket to socket. But I'm not a network engineer. 😊

      1. haensch@t-online.de

        Hello, my question concerns plugs and sockets that can be assembled in the field: if one end of the cable is assembled with a plug and the other end of the cable with a socket, does the same specification T568A or B apply to both sides, or does one of the two end points have to be wired mirror-inverted ?
        Many thanks for competent help!
        VG Eckart

        1. Hello Eckhart! I'm not a network engineer, but logically such an extension always has to be wired 1:1. But maybe there is still someone here who works with network cables every day and who can make a professional statement. 😊

          1. Thank you very much, sounds reasonable and of course makes sense. maybe I just thought too complicated. VG

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