Components of Computer Networks

In this tutorial, we will cover the components of Computer Networks.

A Computer Network basically comprises multiple computers that are interconnected to each other in order to share information and other resources. Multiple computers are connected either with the help of cables or wireless media.

So basically with the help of a computer network two or more devices are connected in order to share a nearly limitless range of information and services which includes;

• Music

• Databases

• Websites

• Documents

• Email and messaging

• Telephony and conferencing

• Printers and Faxes

The above image shows how two devices are connected to each other with the help of the Internet and a laptop is connected to one of them with the help of a cable.

Let us now learn the main components of Computer Networks;

Components of Computer Networks

The key parts that are required to install a network are included in the components of the Computer network. From simple to complex there are numerous types of networks in Computer networks. The components that we need to install for a network mainly depend upon the type of Network. We can also remove some network components according to our needs.

For example: In order to establish a wireless network there is no need for cables.

Given below is a list of components of a Computer Network:

• Network Interface Card(NIC)

• HUB

• Switch

• Repeater

• Router

• Modem

• Server

• Bridge

We are now going to discuss all the above mentioned major components of a Computer Network:

1. Network Interface Card(NIC)

NIC mainly provide the physical interface between computer and cabling.NIC prepares data, sends the data, and controls the flow of data. It can also receive and translate the data into bytes for the CPU to understand.

• NIC is a hardware component that is mainly used to connect one computer with another on a Network.

• The main role of NIC is to move the serial signals on the network cables or media into parallel data streams inside the PCs.

• Transfer rate supported by NIC is 10Mb/s,100 Mb/s ,1000 Mb/s.

• Two or more NIC’s are used in the server in order to split the load.

• The main job of NIC is controlling access to the media.

• NIC can be wired or wireless. In wired NIC, there are cables and connectors that act as a medium to transfer data. While in the wireless card, the connection is generally made using an antenna that uses radio-wave technology

Factors to be taken into consideration when choosing a NIC:

1. Preparing data

2. Sending and Controlling data

3. Configuration

4. Drivers

5. Compatability

6. Performance

2. Hub

Hubs are those devices that are used to link several computers together. Hubs repeat one signal that comes in on one port and then copies it to other ports.

• A network hub is basically a centralized distribution point for all the data transmission in a network.

• Hub is a passive device.

• The hub receives the data and then rebroadcasts the data to other computers that are connected to it. Hub mainly does not know the destination of a received data packet. Thus it is required to send copies of data packets to all the hub connections.

• Also, Hubs consumes more bandwidth on the network and thus limits the amount of communication.

• One disadvantage of using hubs is that they do not have the intelligence to find out the best path for the data packets which then leads to inefficiencies and wastage.

Types of Hub

1. Active Hub:

Active Hubs make use of electronics in order to amplify and clean up the signals before they are broadcast to other ports. Active Hubs are mainly used to extend the maximum distance between nodes. It works both as a wiring center as well as a repeater.

2. Passive Hub:

Passive Hubs are those hubs that connect only to Active Hubs. Passive Hubs are simply used to connect all ports together electrically and these are usually not powered. These hubs are cheaper than Passive hub. Passive hubs neither amplifies the signal nor regenerates the signal.

3. Intelligent Hub:

Intelligent hubs give better performance than active and passive hubs. Nowadays Intelligent hubs are widely used and are in more demand than active and passive hubs. These hubs are mainly used to connect various devices. It supports amplification and regeneration of signals at any point of incoming signals.

Intelligent hub sustains the network along with the selection path. The tasks of both passive and active are manageable by the intelligent hub.

With the help of an Intelligent hub, the Speed and efficiency of the whole network increases which helps to gain the fast and efficient performance of the network.

3. Switch

Switch mainly resembles a Hub. It is a layer-2 device and it is used for the intelligent forwarding of messages. By intelligent we mean the decision-making ability of the switch. As hub works in the way by sending data to all ports on the device, whereas the switch sends the data to only that port that is connected with the destination device.

• The switch is a network component and is mainly used to connect the segments of the network.

• The switch is more intelligent than the network hub.

• Mainly Switches are capable of inspecting the data packets as soon as they are received, then determine the source and destination of that packet, and then forward it appropriately.

• Switch differs from the hub as it also contains ports of different speeds.

• Before forwarding the data to the ports switch performs the error checking and this feature makes the switch efficient.

• As the switch delivers the message to the connected device it was intended for, thus it conserves the bandwidth of the network and offers better performance than the hub.

• The most important feature of the switch is that it supports unicast(one to one), multicast(one to many), and broadcast(one to all) communications.

• The switch makes use of MAC address in order to send data packets to the selected destination ports.

Switches are categorized into 4:

1. Managed Switch
These are expensive switches and are mainly used in those organizations that have large and complex networks. Managed switches are configured using the Simple Network Management Protocol(SNMP). These switches provide a high level of security, complete management of the network thus beside their expensiveness these are used in large organizations because they provide high scalability and flexibility

2. Unmanaged Switch
These are cheap switches and are mainly used in home networks and in small businesses. The unmanaged switch does not need to be configured. Unmanaged switches can be easily set up just by plugging them into the network, after plugging they instantly start operating.

3. PoE Switch
These are referred to as Power over Ethernet switches. With the help of the PoE technology, these switches combine the data and power transmission over the same cable, and with the help of that devices connected to this switch are able to receive both electricity as well as data over the same line. Thus PoE switches offer more flexibility.

4. LAN Switch
LAN switch is referred to as Local Area Network switch and it is mainly used to connect devices in the internal local area network of an organization. These are helpful in reducing network congestion. Bandwidth with these switches is allocated in a manner such that there is no overlapping of data packets in the network.

4. Repeater

The repeater is a Physical layer device. As the name suggests, the repeater is mainly used to regenerate the signal over the same network and it mainly regenerates before the signal gets corrupted or weak.

They are incorporated into the networks in order to extend the coverage area. Repeaters can connect signals by making the use of diffrent types of cables.

• Repeaters are cost-effective.

• Repeaters are very easy o install, and after their installation, they can easily extend the coverage area of the network.

• But there is a problem with repeaters and it is they cannot those networks that are not of the same type.

• Repeaters do not help to reduce the traffic in the network.

Types of repeaters:

Types of repeaters that are available are as follows:

1. Analog Repeaters
These are only used to amplify the analog signals.

2. Digital Repeaters
These are only used to amplify digital signals.

3. Wired Repeaters
These repeaters are mainly used in wired Local area networks.

4. Wireless Repeaters
These are mainly used in wireless local area networks and also in cellular networks.

5. Local Repeaters
These are used to connect segments of a local area network that are separated by a small distance.

6. Remote Repeaters
These are mainly used to connect those local area networks that are far away from each other.

5. Router

The router is a network component that is mainly used to send or receive data on the computer network. The process of forwarding data packets from the source to the destination is referred to as Routing.

• The router is a Network Layer(i.e Layer 3) device.

• The main responsibilities of the router are receiving data packets, analyzing them, and then forwarding the data packets among the connected computer networks.

• Whenever any data packet arrives, then first of all the router inspects the destination address and then consults with its routing tables in order to decide the optimal route and then transfers the packet along this route towards the destination.

• Routers are mainly used to provide protection against broadcast storms.

• Routers are expensive than a hub, switches, repeaters, and bridges.

• Routers can also connect different networks together and thus data packets can also be sent from one network to another network.

• Routers are used in both LAN as well as in WAN(wide area network).

• Routers share data with each other in order to prepare and refresh the routing tables.

Types of Routers:

Different types of routers are as follows:

1.Core Routers
Core routers are mainly used by service providers(like AT&T, Vodafone) or by cloud providers like (Amazon, Microsoft, and Google). Core Routers provide maximum bandwidth so as to connect additional routers or switches. Core routers are used by large organizations.

2.Edge Routers
An edge router is also known as a Gateway router or gateway simply. The gateway is the network's outermost point of connection with external networks and also includes the Internet. These routers are mainly used to optimize bandwidth and are designed in order to connect to other routers so as to distribute data to end-users. Border Gateway protocol is mainly used for connectivity by edge routers.

These are further categorized into two:

• subscriber edge routers

• label edge routers.

3. Brouters
Brouter means bridging routing device. These are special routers and they also provide functionalities of bridges. They perform the functioning of the bridge as well as of router; like a bridge, these routers help to transfer data between networks, and like the router, they route the data within the devices of a network.

4.Broadband Routers
It is a type of networking device that mainly allows end-users to access broadband Internet from an Internet service provider (ISP). The Internet service provider usually provides and configures the broadband router for the end-user.

5.Distribution Routers
These routers mainly receive the data from the edge router (or gateway) via a wired connection and then sends it on to the end-users with the help of Wi-Fi.

5.Wireless Routers
These routers combine the functioning of both edge routers and distribution routers. These routers mainly provide a WiFi connection to WiFi devices like laptops, smartphones, etc. These routers also provide the standard Ethernet routing. For indoor connections, the range of these routers is 150 feet while for outdoor connections it is 300 feet.

6. Modem

The modem is basically a hardware component that mainly allows a computer or any other device like a router, switch to connect to the Internet. A modem is basically a shorthand form of Modulator-Demodulator.

One of the most important functions of the modem is to convert analog signals into digital signals and vice versa. Also, this device is a combination of two devices: modulator and demodulator. The modulator mainly converts the digital data into analog data at the time when the data is being sent by the computer.

The demodulator basically converts the analog data signals into digital data at the time when it is being received by the computer.

7. Server

A Server is basically a computer that serves the data to other devices. The server may serve data to other devices or computers over a local area network or on a Wide area network with the help of the Internet. There can be virtual servers, proxy servers, application servers, web servers, database servers, file servers, and many more.

Thus servers are mainly used to serve the requests of other devices. It can be hardware or software.

8. Bridge

It is another important component of the computer network. The bridge is also a layer-2( that is data link layer device). A bridge is mainly used to connect two or more local area networks together. These are mainly used as they help in the fast transferring of the data.

But these are not versatile like routers.

Thus Bridge can mainly transfer the data between different protocols (i.e. a Token Ring and Ethernet network) and operates at the data link layer or level 2 of the OSI (Open Systems Interconnection) networking reference model as told above.

Bridges are further divided into two:

• Local bridge
  These are ordinary bridges.

• Remote bridges
  These are mainly used to connect networks that are at a distance from each other. Generally Wide Area Network is provided between two bridges

Some Bridge protocols are spanning tree protocol, source routing protocol, and source routing transparent protocol.