Telephone Plugs and Sockets for Australia

Technical and Reference >> Telephone Plugs and Sockets for Australia


There are currently three different types of line termination connectors used in Australia for telephone and data use.


600 Series - Australian Style
This series is what is commonly called the "old Australian type" and has been installed in Australia, primarily by Telstra, for approximately 30 years. There is a huge installed base of this type of connector.

RJ12 series - US modular
This type of connector has been installed in Australia for a period of approximately 5 years, originally developed in the USA by Bell Labs (the same Bell that invented the telephone) by engineers Charles Krumreich and Edwin Hardesty, it has now become the most widely used telephone connector in the world. You will see it is used in the connection port for most telephones, faxes etc.

This connector is quite often misnamed, however in Australia it is commonly called the RJ12. In the USA it is called RJ11 or RJ14, depending on wiring configuration. RJ12 can used to connect a maximum of 6 wires.

RJ stands for "registered jack" - not Ross Jackson, our MD, as many people think !

RJ45 series - US modular
This connector is an evolution of the RJ12, having a wider body to allow 8 wires to be connected. Telstra and Optus, amongst others, are installing this connector into homes and offices across Australia.

It cannot be plugged into a RJ12 socket, however, a RJ12 can be plugged into a RJ45 socket, using a reducing sleeve.

Australian 600 Series Details

How to install
Installation Diagram
1. Loosen screw "A" and remove the cover.
2. Remove screw "B" and withdraw the plug.
3. Replace screw "B" and make sure it sits flush. If the screw is too long replace it.
4. Replace cover and tighten screw "A"

Telstra Colour Coding
Telstra Colour Coding
TIP (L+)
white (2)
blue (6)

RJ12 and RJ45 Series Details

Registered Jacks (RJ)
Any of the series of jacks, described in the Code of Federal Regulations, Title 47, part 68, used to provide interface to the public telephone network.

RJ (registered jacks, sometimes described as RJ-XX) are a series of telephone connection interfaces (receptacle and plug) that are registered with the U.S. Federal Communications Commission (FCC). They derive from interfaces that were part of AT&T's Universal Service Order Codes (USOC) and were adopted as part of FCC regulations. The term jack in the USA sometimes means both receptacle and plug and sometimes just the receptacle, although in Australia it means socket. A plug is male and a socket is female.

RJ11This plug and socket combination is not used for wall termination. It is the very small connectors used to connect your telephone to the handset..

RJ-12 As mentioned above, the most common telephone connector in the world is the RJ-12 jack, which can have six conductors but usually is implemented with four or sometimes two. The RJ-12 jack is likely to be a socket that your household or office phones are plugged into. In turn, these sockets connect to the outside longer wires known as twisted pair, which run to the telephone companies switch or to a private branch exchange (PABX). The four wires are usually characterised as a red and green pair and a black and white pair. The red and green pair typically carry voice or data. On an outside phone company connection, the black and white pair may be used for Iow-voltage signals such as phone lights. On a PBX system, they may be used for other kinds of signalling.Your computer modem is usually connected to a RJ-12 jack.

6 position / 4 contact modular plugs 6 Position 4 Contact Modular Plug
2 white/orange  
3 blue/white blue/white
4 white/blue white/blue
5 orange/white  

6 position / 6 contact modular plugs 6 Position 6 Contact Modular Plug
1 white/green
2 white/orange
3 blue/white
4 white/blue
5 orange/white
6 green/white

As mentioned above, Telstra and Optus are now installing this type of socket in homes. The RJ-45 is a single-line jack for digital transmission over ordinary phone wire, either untwisted or twisted. The interface has eight pins or positions. For connecting a modem, printer, or a data PABX at a data rate up to 19.2Kbps, you can use untwisted wire. For faster transmissions in which you're connecting to an Ethernet 10/100/1000BaseT network, you need to use twisted pair wire. (Untwisted is usually a flat wire like common household phone extension wire. Twisted is often round.).

RJ45 is also called Category 5 or "Cat 5" in Australia, which refers to a specification for data transmission. Cat 5 or RJ45 are physically compatible, and both are suitable for telephones or modems depending on data rate requirements.

8 position modular plugs
Plug positions T568A T568B
1 white/green white/orange
2 green orange
3 white/orange white/green
4 blue blue
5 white/blue white/blue
6 orange green
7 white/brown white/brown
8 brown brown

Flat Cord (USOC)

Modular Cord Writing
To identify whether a patch cord is wired straight through or cross-over, hold either end of the cable so the plugs are aligned side by side with the contacts facing you (with the clip down and contacts facing upwards) and compare the wire colour coding. If they appear in the same order from left to right the cord is wired straight through. If they appear reversed on the second plug then the cord is a cross-over.

Useful phone numbers
Telstra Line Number ID 12722123
Telstra "Call me back" to test ringing 12722199
Telstra Calling Number Display- Block this number prefix 1831
Telstra Calling Number Display- Send this number prefix 1832
Telstra Calling Number Display Status 127220
Telstra Directory Assistance 12455
Telstra Call Connect 12456
Telstra Cable Locations 1100