Theory -66 :- Fiber Optics And Coaxial Cable : RJ-45, RJ-11 BNC Etc.

 

There are several types of network cables. Each type of network cable uses specific types of connectors to connect to another network cable or network interface card. To join two network cables or to connect a network cable to a NIC, you need appropriate connectors. In the following section, we will discuss some most common and popular network media connectors.

Barrel connectors

Barrel connectors are used to join two cables. Barrel connectors are female connectors on both sides. They allow you to extend the length of a cable. If you have two small cables, you can make a long cable by joining them through the barrel connector. 

Barrel connectors that are used to connect coaxial cables are known as BNC barrel connectors. 

The following image shows BNC barrel connectors. 

Barrel connectors that are used to connect STP or UTP cables are known as Ethernet LAN jointers or couplers. The following image shows Ethernet LAN jointers or couplers.

 

Barrel connectors do not amplify the signals. It means, after joining, the total cable length must not exceed the maximum supporting length of the cable. For example, a standard UTP cable supports a maximum distance of 100 meters. You can join two UTP cables if their sum is not more than 100.

 

For example, you can join the following cables.

Cable 1 (45 meters) + cable 2 (30 meters) = joint cable (75 meters = 45 meters + 30 meters)

The length of the joint cable is less than 100 meters. 

But you can't join the following cables.

Cable 1 (65 meters) + cable 2 (45 meters) = joint cable (110 meters = 65 meters + 45 meters)

The length of the joint cable is more than 100 meters.

 

F connectors

An F connector is used to attach a coaxial cable to a device. F connectors are mostly used to install home appliances such as dish TV, cable internet, CCTV camera, etc. The following image shows F connectors.

 

F connectors

 

Terminator Connectors

When a device places signals on the coaxial cable, the signals travel along the end of the cable. If another device is connected to the other end of the cable, the device will receive the signal. But if the other end of the cable is open, the signals will bounce and return in the same direction they came from. To stop signals from bouncing back, all endpoints must be terminated.

 

A terminator connector is used to terminate the endpoint of a coaxial cable. The following image shows terminator connectors.

 

 

T type connectors

A T connector creates a connection point on the coaxial cable. The connection point is used to connect a device to the cable.

The following image shows T-type connectors.

 

T Connector

 

RJ-11 Connectors

RJ-11 connectors have the capacity for six small pins. However, in many cases, only two or four pins are used. For example, a standard telephone connection uses only two pins, and a DSL modem connection uses four pins. They have a small plastic flange on top of the connector to ensure a secure connection.

The following image shows RJ-11 connectors.

 

RJ-11 Connectors

 

RJ-45 Connectors

RJ-45 connectors look likes RJ-11 connectors, but they are different. They have 8 pins. They are also bigger in size than RJ-11. RJ-45 connectors are mostly used in computer networks. They are used with STP and UTP cables. Some old Ethernet implementations use only four of the eight pins. Modern Ethernet implementation uses all 8 pins to achieve the fastest data transfer speed.

The following image shows RJ-45 connectors.

 

RJ- 45 Connectors

 

DB-9 (RS-232) connectors

A DB-9 or RS-232 connector connects a device over a serial port. It has 9 pins. It is available in both male and female connectors. It is used for asynchronous serial communication. The other side of the cable can be connected to any popular connector type. For example, you can connect one side of the cable with a DB-9 connector and the other side of the cable with another DB-9 connector or with an RJ-45 connector or with a USB connector.

The following image shows DB-9 connectors.

 

DB-9 Connectors

 

One of the most popular uses of a DB-9 connector is to connect the serial port on a computer with an external modem.

 

Universal serial bus (USB) connectors

USB connectors are the most popular. They support 127 devices in the series. All modern computers have USB ports. Most devices that you can connect to the system have USB ports. Some examples of devices that support or have USB ports are mice, printers, network cards, digital cameras, keyboards, scanners, mobile phones, and flash drives.

 

USB Connectors

 

If the device has a USB port, you can use a cable that has a USB connector on both ends to connect the device to the computer. If the device does not have a USB port, you can still connect the device to the USB port. For that, you can use a cable that has a USB connector on one side and the corresponding connector on the other.

 

Fiber Cable Connectors

A variety of connectors are used to connect fiber cables. Some popular connectors are ST, SC, LC, and MTRJ. Let's discuss these connectors.

 

SC Connectors

SC connectors are also known as subscriber connectors, standard connectors, or square connectors. An SC connector connects to a terminating device by pushing the connector into the terminating device, and it can be removed by pulling the connector from the terminating device. It uses a push-pull connector similar to audio and video plugs and sockets.

The following image shows SC connectors.

 

SC Connectors

 

Straight tip (ST) connectors

Straight tip (ST) connectors are also known as bayonet connectors. They have a long tip extending from the connector. They are commonly used with MMF cables. They use a half-twist bayonet type of lock. An ST connector connects to a terminating device by pushing the connector into the terminating equipment and then twisting the connector housing to lock it in place.

The following image shows ST connectors.

 

ST Connectors

 

LC Connectors

LC connectors are known as Lucent Connectors. For a secure connection, they have a flange on top, similar to an RJ-45 connector. An LC connector connects to a terminating device by pushing the connector into the terminating device, and it can be removed by pressing the tab on the connector and pulling it out of the terminating device.

The following image shows LC connectors.

 

LC Connectors

 

MTRJ connectors

An MTRJ connector connects to a terminating device by pushing the connector into the terminating device, and it can be removed by pulling the connector from the terminating device. It includes two fiber strands: a transmit strand and a receive strand in a single connector.

The following image shows MTRJ connectors.