RJ-11 Connectors

RJ (Registered Jack) -11 connectors are small plastic connectors used on telephone cables. They have capacity for six small pins. However, in many cases, not all the pins are used. For example, a standard telephone connection only uses two pins, while a cable used for a DSL modem connection uses four.

RJ-11 connectors are somewhat similar to RJ-45 connectors, which are discussed next, though they are a little smaller. Both RJ-11 and RJ-45 connectors have small plastic flange on top of the connector to ensure a secure connection. Figure 5 shows two views of an RJ-11 connector.

Figure 5 RJ-11 connectors.

RJ-45 Connectors

RJ-45 connectors are the ones you are most likely going to encounter in your network travels. RJ-45 connectors are used with twisted-pair cabling, the most prevalent network cable in use today. RJ-45 connectors resemble the aforementioned RJ-11 phone jacks, but support up to eight wires instead of the six supported by RJ-11 connectors. RJ-45 connectors are also larger. Figure 6 shows the RJ-45 connectors.

Figure 6 RJ-45 connectors.