Copper Connector Cable Types

RJ-45 Connectors

What is an RJ?

RJ stands for "Registered Jack". They are many different types of RJ connectors which can be identified by their numbers. Some may be different physically. Some may look the same, but they are wired differently for different applications.

What are RJ-45 Connectors?

RJ-45 connectors are used with 4-pair (8-wire) cables. These connectors within an RJ-45 can be referred to as 8P8C. The 8P8C stands for 8-position/8-contact. In an 8P8C, all eight potential wire positions are supplied with contacts. These contacts allow for all wires to carry signals if needed.

When / Where is RJ-45 Cabling Used?

RJ-45 is used for Ethernet twisted pair cabling.
A patch panel has 110 block IDCs on one side with pre-wired RJ-45 jacks on the other side
An RJ-45 patch cord is used to connect the port to another network port.
1. This port is usually a switch port that is housed in the same rack.
In network loopback adapters
- Contains a specially wired RJ-45 plug with a 6-inch stub of cable. The wiring pinout is Pin 1(Tx) to Pin 3(Rx) and Pin 2(Tx) to Pin 6 (Rx)
In an AUX port for Out-of-Band management. An AUX port means it is a managed switch, which means it can be configured and monitored over several different interfaces.

This port is designed to connect to a modem and provides remote access over a dial-up link.
With the AUX port enabled and configured, a modem can be connected to it using...

An RS-232 serial cable
A specially wired RJ-45 rollover cable and terminal adapter (RJ-45 to DB9)
A management cable (DB9 to RJ-45)

A console port connection (wired differently than Ethernet)
Wiring diagrams show information about the termination of twisted pairs in an RJ-45 or Insulation Displacement Connector (IDC).

An example of an IDC are the 110 blocks and 66 blocks!

Copper Termination Standards of RJ-45 connectors

Pin	Wire Color (T568A)	Wire Color (T568B)	10/100 Mbps	1/10 Gbps
1	Green/White	Orange/White	Tx+	BixA+
2	Green	Orange	Tx-	BixA-
3	Orange/White	Green/White	Rx+	BixB+
4	Blue	Blue	N/A	BixC+
5	Blue/White	Blue/White	N/A	BixC-
6	Orange	Green	Rx-	BixB-
7	Brown/White	Brown/White	N/A	BixD+
8	Brown	Brown	N/A	BixD-

A picture of the termination standards A and B

RJ-11 Connectors

What are RJ-11 Connectors?

RJ-11 Connectors are smaller than RJ-45 cables. While there is room for six wires, only the four center wires of an RJ-11 are used. Typically, in an RJ-11 connector, the innermost pair, that is, the pair wired to pins 3 and 4, carries the dial tone and the voice circuit. The other pair is usually unused but it can be deployed for a secondary circuit.

When is RJ-11 Cabling Used?

Used with 2-pair UTP
Used with 3-pair UTP
Used for dial-up systems / telephone systems

RJ-11 connectors connects modems to phone jacks via an RJ-45 ethernet port!

Fiber Optic Connector Cable Types

ST (Straight Tip)

A ST uses a push-and-twist (remember by 'Stick and Twist') locking mechanism. Once used for multimode networks, it is seldom used for Ethernet installations.

SC (Subscriber Connector)

A SC uses a push/pull design (remember by 'Stick and Click!'). This allows for easy insertion and removal. SC's are used for SMF (single mode fiber) as well as MMF (multimode fiber). SC's are commonly used for Gigabit Ethernet.

LC (Lucent Connector / Local Connector)

LC is a small-form-factor connector with a tabbed push/pull design. LC is similar to SC, however is smaller in size. The smaller size of an LC allows for higher port density. LC is a widely adopted form factor for Gigabit Ethernet and 10GbE

MTRJ (Mechanical Transfer Registered Jack)

MTRJ is a small-form-factor duplex connector. It uses a snap-in design and is used for multimode (multiple modes of light, such as that of fiber optics) networks.