When Would You Typically Use An RJ11 Connector? RJ45 Vs. RJ11

rj11 connector

One of the first types of modular connectors used for phone and modem lines was the RJ11 connector. It is a modular six-position plug or jack with four conductors that is frequently used in domestic and small office settings.

When would you typically use an RJ11 connector? Analog telephones are connected to the phone jacks using an RJ11 connector. Cat 3, Cat 5, and higher twisted pair cables use RJ45 connectors.

Learn more about the RJ11 connector by reading on.

What Is RJ In RJ11?

A Registered Jack, or RJ, is a standardized telecommunication network interface for connecting voice and data equipment to a service provided by a local exchange carrier or long-distance carrier. Both single-pair and multi-pair telephone systems employ an RJ. The RJ-45 Registered Jack, which is utilized in Ethernet networks, is the most popular type.

The RJ standards are defined according to the number of positions and wires in the connector. For instance, some well-known registered jacks are RJ11, RJ12, RJ14, RJ25, and RJ45.

These were initially called modular connectors, first invented by Bell Systems were introduced in 1973 to create a standard for connecting telephone lines with the distribution hardware. The protective couplers, which vary depending on the company, could be changed. Small, easy to handle, and cheap to produce, these connectors were all great qualities.

Also Read: What Are F-type Connector?

When To Use An RJ11 Connector? 

The RJ11 is mainly used in telephone lines. Since the connector has six positions, it can accommodate up to three telephone lines (two wires per pair are required for communication).

It attaches a phone to a wall outlet and its handset to the phone.

For use on telephone lines, there are two types of RJ11 jacks or sockets.

  1. RJ11C: Tabletop telephones have an RJ11C jack. It includes a cord to connect to the line.
  2. RJ11W: For wall telephones, an RJ11W jack is used. The RJ11C jack function is also available.

Older models of fax machines and modems also use RJ11, even though it is primarily used in voice communication lines.

Many devices now use RJ45 instead of RJ11 for connectivity. However, one benefit of RJ11 is that it is simple to plug into the RJ45 jack.

Difference Between RJ11 and RJ45

rj11 connector

The RJ45 connector, which is a more recent, modular, self-sealing, and compact technology, is used to connect Ethernet cables to various electronic devices. The ethernet interfaces are connected using the RJ45, an 8-pin connector. A connector 8P8C is what it is called.

  1. Straight-over cable
  2. Crossover cable

The traditional PSTN phone networks are terminated using RJ11 cables. A four-pin connector known as RJ11 is used to terminate telephone wires. The RJ11 is used to wire a single phone line and technically uses the center of 2 of the 6 available contacts. It is the typical connector used to attach a phone to the wall and a handset to a phone.

RJ11 vs. RJ45 Differences


  • Ethernet cables are connected by RJ-45.
  • The structure of RJ45 is of a larger size
  • The bandwidth supported by RJ-45 is 10 Gbps over ethernet
  • The number of wires connected with RJ45 is 8
  • RJ45 is an 8P8C connector


  • Telephone wires are connected using RJ-11 connectors.
  • The structure of RJ11 is comparatively small
  • The bandwidth supported by RJ-1 is 24 Mbps
  • The number of wires connected with RJ11 is 4
  • RJ11 is a 6P4C connector

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Drawbacks Of RJ11 And RJ45 Connectors

  • The fact that RJ11 and RJ45 connectors are not weatherproof is a disadvantage. Since they will be exposed to the elements, they shouldn’t be used in those applications.
  • The RJ11 and RJ45 connectors’ lack of durability is another disadvantage. If they are overly bent or twisted, they may suffer damage.
  • Finally, there is no compatibility between RJ11 and RJ45 connectors. This means that neither an RJ11 connector nor an RJ45 connector can be used in an Ethernet application or a telephone application, respectively.

Use an adapter if you want to connect a device with one type of connector to a device with a different type of connector. You can connect an RJ11 connector to an RJ45 jack or an RJ45 connector to an RJ11 jack using adapters that are available.

RJ45 And RJ11: Which One Is Better?

It is crucial to take your intended application into account when deciding between RJ11 and RJ45.

RJ11 is a better option if you need a connector for a telephone application.

RJ45 is a better option if you require a connector for an Ethernet application.

Other Types Of RJ Connectors

The most popular connectors are RJ11, RJ14, and RJ25. Phones can be connected to any of the three jack types for one-, two-, or three-line services, respectively. These are all modular connectors with six positions available. In actuality, the RJ11 wires a single phone line by using the center of two of the six available contacts. RJ14 is similar to Using a 6P4C configuration, which uses 4 connectors out of the 6 positions, RJ11 is used, but it is wired for two phone lines. RJ25 uses all 6 of the available positions (6P6C) and is able to connect 3 lines. RJ61 is a similar registered jack for 4 lines; it uses an 8P8C configuration similar to the RJ45.

RJ22, also called an RJ10, is the smallest of the modular plugs. When used in handset cords, it has a 4P4C configuration. It is not an official ACTA (Administrative Council for Terminal Attachments) specification.

RJ12 connectors are also similar to RJ11 but are configured as 6P6C. They are used to connect a phone line to the main telephone system, which is a small exchange-like system used by businesses to connect to the carrier on the outside and build a network of phones and extensions on the inside. Since RJ12 has all the connectors RJ11 requires (plus four more), RJ12 connectors can be used in place of RJ11 connectors.

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Why might you use an rj11 connector?

Analog telephones are connected to the phone line using the RJ11 connector. RJ45 connectors are used with twisted-pair cables that are Cat 3, Cat 5, and higher. Use type F or BNC connectors with coaxial cables. Some DSL connections and remote access (modem) use RJ11 connectors.

What are the Additional Uses of RJ11?

RJ11, which stands for Registered Jack, was created by phone companies in the 1970s and is used for analog voice lines. A 2-wire connector, this one has just one pair of connectors. The metal pins at the bottom of a phone jack, known as RJ11, typically have six positions.

RJ45 or RJ11, which is better?

RJ45 has 8 wires inside while RJ45 is larger than RJ11, which has four wires. RJ45 cable connectors cannot be plugged into RJ11 interfaces, ports, or slots, but they can be plugged into the opposite (though you should avoid doing this as it could harm the RJ45 port).

RJ11 is used by what devices?

Phones, ADSL lines, and modem cables RJ11 is mostly used for voice applications. RJ45 is used in computer networking to connect cable modems to Wi-Fi routers or to create Ethernet connections.

What makes RJ11 and RJ12 different from one another?

Following RJ11 is RJ12. Both RJ11 and RJ12 have 6P4C and 6P6C connectors, respectively.

The number of wires (pins/connectors) used by each of them varies. There are still six positions available. RJ11 has four wires, while RJ12 has six.

RJ12 can connect 3 telephone lines, as opposed to RJ11’s 2 telephone line capacity.

Which cable does RJ11 utilize?

Telephone lines employ RJ11 technology. Thus, twisted-pair cables with four wires are the most common type of cable used with RJ11.

RJ11 telephone lines can also be connected to the Cat5 cables. Just one of the four pairs of wires should be used to terminate with an RJ11 connector and connect to the phone line.

What types of connectors are used by telephones?

The name “RJ11” stuck to refer to the connector used on phone cords because it was used to identify the wiring scheme for a single-line phone. Today, RJ-11 is widely used in the connectivity industry to denote a 6-position, 4-conductor modular connector or jack.