computer networking devices explained | Hubs, Router, Switch, Bridge, repeater explained

Computer Networking Devices Explained

What are Networking Devices ?

Networking devices are used to create a Computer Network. A computer network, is the interconnection of computers and various devices in strategic infrastructure, so that they can share information and resources between them. 

Why do we need a computer network?

A computer network helps us to share the information and resources remotely, with the help of a computer network multiple users can share their resources and information from different locations.

Various hardware resources such as a printer, scanner, memory, processor, etc. can also be shared over a computer network. Which results in cost reduction, performance optimization, etc.

Networking Devices

There are a lot of networking devices available in the market which helps us to create a Computer Network. Some of them are:

• Router
• Hub
• Switch
• Bridge
• Gateway
• Repeater
• Network interface card (NIC)
• Modems
• Multilayer switch
   
  
  

Some of the networking devices such as hubs, repeater are no longer use in Computer Networking. 

 

Different types Networking Devices Explained.

 

 NIC (Network interface card)

NIC

A network interface card is used in a computer system to connect it to the network. NIC helps computer systems to communicate with other systems over a network. It provides an ethernet which helps to establish a local LAN network.

In a motherboard, the ethernet port is generally available below the VGA port. Every NIC card comes with a unique id, which is written on its chip. Every NIC card has a connector or ethernet port, in which we can connect a cable. The cable carries the signal from the computer system to make the interface with the router or modem.

A NIC card is a layer 2 device, which means that it works on both physical and data link layer of the network model. NIC cards are of two types:

 

1.  Wired NIC
2.  Wireless NIC
   
   
   

Wired NIC is used with desktop computer, if there is no inbuilt network adapter available on it or if the user wants to add an ether net port to make a LAN network. Wired NIC can be used to establish a Wired LAN network

Wireless NIC comes with portable computing devices such as Laptops, Tablets, or single-board computers like Raspberry PI, Banana PI, etc. Wireless NIC can be used to establish a Wireless LAN network.

NIC cards have their processing unit available on them. NIC card consists of memory sockets, jumpers, bus connectors, RJ-45, AUI, etc. NIC card can be easily connected with a computer's motherboard using its PCI, PCIe, or PCI-X expansion slots.

After successfully connecting the NIC card with the motherboard user has to install the driver on the computer system, required to run the wired or wireless NIC card.

 

Repeaters

Repeaters

Repeaters are the physical hardware and commonly networking devices. The repeater is used to repeat the signal from one port to another coming from another networking device or a computer this means they are used to extend the networks.

A repeater amplifies a weak inbound digital signal to string outbound digital signal. The repeater receives the electrical signal from a switch from one port through O.F (optical fiber cable) or twisted pair cable. Once the electrical signal is received, the repeater amplifies the signal and retransmit it to another port.

Multiple computers can receive the amplified signal depending on the configuration of the repeater. The repeater is a layer 1 device, which means it can understand the electrical signal or optical signal only and it works on the physical layer of the network model.

Nowadays repeater is replaced by an optical amplifier such as broadband, which is an intelligent form of a repeater because an optical amplifier doesn't need to convert an optical signal to an electrical signal for its amplification. Instead, it directly amplifies the optical signal with the help of bulk lasers. This means broadband can also increase the length of a network.

HUB

HUB

Hub is a physical hardware networking device that is used to connect the individual computer system to the network so that they can communicate with each other. The hub broadcasts the incoming signal to all of the devices attached to it, which means when a data packet is received it is sent to all of the ports for the transmission. It is a layer 1 device which means that it doesn't understand any kind of address, all it does is repeat the incoming data to all the ports available on it.

The hub provides a central convergence point for the networking cabling of multiple computer systems or other networking devices. The hub works on the physical layer of the network model, this means it receives the data sent by one node and forwards it to all other nodes.

A hub is a half-duplex device, meaning that for a particular interval of time it can only send or receive data. It cannot perform both operations at the same time, which directly means that it has 1 collision domain.

Due to the transmission of the received signal to all of the ports the network traffic also increases, which means that it cannot be used on a busy network where the transmitting and receiving speed of computer systems is very fast. But still, the hub offers a convenient and affordable way to make your own private LAN network.

There are two types of hub available in the networking field:

1. Active hub 

2. Passive hub
   
   

Active hub not only transmits the incoming signal to multiple computer systems attached to it but also filters and amplifies the received signal. It amplifies the received signal before forwarding it to other nodes. This means that an active hub can work as both repeater and a hub.

A passive hub simply transmits the received signal to all of the nodes without filtering and amplifing the signal.

Hub is not an efficient device because it wastes the bandwidth by sending unwanted data to all of the nodes. It is also not secure networking because every computer system attached to the network receives the data, which can easily be misused. Nowadays hubs are replaced by Switch.

 

BRIDGE

BRIDGE

A bridge is a layer 2 device which means that it works on both the physical and data link layer of the networking model. A bridge is used to segment the network. This means it allows the large network to be broken into a smaller network which results in the reduction of traffic also.

When data reaches bridge it decides whether or not to forward the data, it does this by looking at the destination and source of mac address. A bridge has about 2 ports only for data transmission and dissuasion.

A bridge not only transmits the data but also filters it that's it is also called an intelligent form of the hub. Bridge filters the incoming data at a network boundary, and then forwards the data packet in the form of the frame to the correct location by identifying the mac(medium access control) address of the source and the destination.

A bridge has 2 collision domains which make it able to operate on a busy network. A bridge receives, inspects and store the incoming data or signal and the then transfer it in the form of frames to the destination node.

Because bridge does not send the incoming data to all of the nodes it saves bandwidth and provides security also.

There are many types of bridges available some of them are local bridges, remote bridges, and wireless bridges. The only thing that bridge lacks is the number of the port. Bridge used to join the workgroups like a hub but it also isolates the network which results in the reduction of data traffic problems or it simply segments the network.

 

SWITCH

Switch

A switch in simple language is the combination of hub and bridge, it is a layer 2 device, which can learn mac address or layer 2 address. Like hub, the switch connects individual computer system to the network so that they can communicate with each other, but it also filters, stores, and forward the data packets to the particular port with the help of mac address, unlike the hub. A switch consists of 16 to 24 ports commonly.

A switch operates at both the physical and data link layers of the network model. Just like a bridge it also segments the network or workgroup which results in the increment of the network speed. This means that a switch can easily operate on a busy network also. A switch also has multiple collision domains.

As the switch sends the data to a particular port it saves the network bandwidth. It is also a full-duplex device which means that it can send and receive the data at the same time. Unlike hub switch does not send the incoming data to all the ports, instead, it identifies the transmission port by remembering its's mac address. Which results in the increment of security and consistency of the network.

The disadvantages of the switch are that it is very hard to configure and manage, the cabling cost is also high and if a particular computer system fails, then it is hard to troubleshoot it because every time the switch restarts it relearns the mac addresses of all computer system attached to it. 

Also if in some case if the switch got malfunctioned the whole network will fail, then the engineer or networking guy had to do the cabling connection of all the computer systems again.

But still switch is a good option as compared to hub or bridge, if you want data security, data integrity and also the sending and receiving speed.

 

ROUTER

Routers

Nowadays router is the most common device. It is a physical hardware networking device that is generally used as a doorway out of the internal network. A router has a built-in switch, which means that the operation that switches performs can also be performed by a router.

Router uses an IP (internet protocol) address to differentiate between multiple networks, that's why it is also called a layer 3 device which means that it can understand both mac and IP address. As compared to the hub, repeater, bridge, and switch router is highly configurable because it contains an onboard programming paradigm also.

Router always uses the same protocol. It also acts as a firewall to the incoming traffic, it uses IPsec to protect the network user from hidden malware or vulnerabilities in the incoming data. The router is a full-duplex device, it has multiple collision domains also.

Router not only provides transmission and filtering of data but also finds the best shortest path for the transmission of the data packet. The traveling packet contains the destination and sources address that helps the router to create an optimum routing for the transmission. 

Router uses a routing table and various algorithms to find the most efficient or optimum path for sending the data to its destination network.

Router has its central processing unit, which provides the service of serial communication and many other services such as universal serial bus, fast ethernet, etc. The router has its ram, flash memory, and NVRAM.

Router has an ADSL port to connect a telephone, power button, WPS push button, reset button to reset the router to the factory configuration, ethernet port to connect the router to the computer, or an ethernet LAN, USB port, etc.

Router can also connect different types of the network which follow different topologies for example ethernet and token ring, token ring, and token bus, token bus and FDDI, etc.

Routers are of 2 types:

1. Static routers

2. Dynamic routers
   
   

Static router needs a specific routing path that the user has to enter to transmit the data.

Whereas, a dynamic router doesn't need any kind of input of routing path. Instead, it routing paths by itself with the help of routing tables and different algorithms.

Router is an expensive device and it is also difficult to configure and maintain. But router is also considered to be one of the best networking devices ever created. 

 

GATEWAY

Gateway

Just like a router a gateway also can be used as a doorway out of the internal network. But unlike a router, a gateway can be a software and hardware device. Which can be used to connect two or more networks of dissimilar types. A gateway uses a different protocol for communication between two different networks. That's why a gateway is also called a protocol converter.

This means that a gateway can be used for the interconnection of networks based on different protocols. As a router, the gateway is also a layer 3 device but it works on the presentation, session, and application layer.

A gateway can create communication between the networks which have different architecture and environment with the different communication protocol.

A gateway has 3 axis accelerometer, GPS, GPRS, OBD2, etc. It has wifi, Bluetooth, ethernet for RFID readers, and antennas.

A gateway device can have ethernet, USB, HDMI, speaker, AV port. It also has ports for micro USB and Micro sd card.

Conclusion

 

To create a secure and fast network proper understanding of networking and networking devices is necessary. Even though devices like repeater, hub, bridge are not in use much, we should have an idea about them. As they help to understand the other devices such as a router, switch, gateways, etc. Networking devices are the basic building blocks of a network that's why it is necessary to have a proper understanding of them.