RJ11 and RJ12 connectors are standard registered jacks that people use to wire their telephone lines. Both of them use the same six-slot connector but differ in the wiring pattern and the number of wires they use.
In RJ11, only four wires are terminated in the connector, whereas in RJ12, six wires are terminated in the connector. This section will identify all the differences between them. So let’s start with the comparison chart.
Content: RJ11 Vs RJ12 Connectors
|Basis for Comparison||RJ11||RJ12|
|Full Form||Registered Jack 11||Registered Jack 12|
|Connector/ Wiring Pattern||6P2C or 6P4C||6P6C|
|Cable||Flat telephone cable||Flatline cord|
|Used for||Mainly used for connecting telephone lines and connecting modems||Commonly used for connecting telephone lines, also for Keyed telephone systems and PBXs|
|Popularity||Very common as it is used in the majority of phone units||Quite uncommon but still used in some large companies|
|Connects||Capable of connecting two telephone lines||Capable of connecting three telephone lines|
What is RJ11 Connector?
RJ11 is a standard registered jack mostly used to connect telephone equipment. But as far as networking is concerned, RJ11 is even used to connect the computer to a local area network through the computer’s modem.
RJ11 is a 6P4C connector which has six positions and four contacts. So, the RJ11 cable has four copper wires connected to the centre of the connecter leaving rest two contact unused. Thus, the RJ11 can connect two telephone lines and one pair of wires for each telephone line.
The RJ11 locks itself into place with a single locking tab, and it resembles RJ-45 but is a little bit smaller. Although we can use RJ11 to create a local area network, the RJ45 connector is usually used for this purpose.
What is RJ12 Connector?
RJ12 is the updated version of RJ11; they are of the same size. But RJ12 uses the 6P6C wiring standard and utilizes all six positions in the connector. Thus, RJ12 can connect three telephone lines and one pair of wires for each telephone line.
Although both connector are used for telephone lines, some other applications take advantage of the additional two connectors, such as keyed telephone systems and PBXs.
Key Differences Between RJ11 and RJ 12 Connector
- The full form of RJ11 is Registered Jack 11, whereas the full form of RJ12 is Registered Jack 12.
- The wiring pattern of RJ11 is 6P2C, i.e., 6 positions 2 contacts or 6P4C, i.e., 6 positions 4 contact. However, the wiring pattern of RJ12 is 6P6C, i.e., 6 positions and 6 contacts.
- RJ12 is comparatively less popular than RJ11 as RJ11 is commonly used in the home for telephone lines and connecting modems. On the other hand, RJ12 is used only in large companies for centralized telephone networks.
- RJ11 connector uses a flat telephone cable with 4 copper wires inside it. However, RJ12 uses a flat telephone cable with 6 copper wires inside it.
- The RJ11 connector can connect two telephone lines, whereas the RJ12 connector can connect three telephone lines.
RJ11 and RJ12 are commonly used for connecting telephone lines and use the same six-slot connector. The only way that both differ is in their wiring pattern. RJ11 utilizes only four slots out of 6, whereas RJ12 utilizes all six slots. However, RJ12 is less popular today than RJ11 because we can see RJ11 in homes connecting telephone lines and modems, whereas large companies only use RJ12 to connect telephones to the centralized telephone network.