Table of Contents

Networking means connecting two or more computers at dispersed locations to exchange information. A system of interconnected computers and computerized peripherals such as printers is called computer network. This interconnection among computers facilitates information sharing among them. Computers may connect to each other by either wired or wireless media.

Advantages of Computer Network

Advantages of using computer networking are as follows:

  1. Hardware Sharing - Users can share peripheral devices like printers and scanners, optimizing their use and reducing the need for each user to have their own. 
  2. Software Sharing - Networks allow for the sharing of software applications, simplifying distribution and updates across multiple devices. 
  3. Seamless Communication - Networks enable communication via email, instant messaging, and video conferencing, allowing for fast and efficient information exchange. 
  4. Collaborative Work - Users can work together on shared documents and projects in real-time, boosting productivity and teamwork. 
  5. Centralised Storage - Data can be stored on central servers or cloud platforms, making it easier to manage, back up, and secure. 
  6. Remote Access - Users can access network resources, files, and applications from remote locations, providing flexibility for mobile and home-based work. 
  7. Reduced Costs - By sharing expensive hardware and software, as well as a single internet connection, networks significantly reduce IT infrastructure costs.
  8. Enhanced Security - Networks can implement centralized security measures, including firewalls, encryption, and access controls, to protect data and systems. 
  9. Increased Reliability - Centralized management and redundancy can improve system reliability, as network issues may not affect the entire system or individual workstations as severely. 
  10. Scalability - Network infrastructure can be easily expanded by adding more devices and users to accommodate growth without major disruptions. 
  11. Flexibility - Networks offer the flexibility to adapt to evolving needs, allowing users to access various resources and services as required. 

Disadvantages of Computer Network

Disadvantages of using computer networking are as follows:

  1. High Set Up Costs - Setting up a network requires expensive hardware such as cables, switches, and routers, which can be a significant initial investment. 
  2. Maintenance Costs - Ongoing maintenance, software updates, and the need for specialized personnel to manage the network also contribute to high costs. 
  3. Complex Setup - Designing and implementing a network, especially a large one, is a complex process that requires specialized technical knowledge. 
  4. Expert Assistance - Networks require continuous monitoring, management, and troubleshooting by skilled personnel to ensure proper functionality and performance.
  5. Security Risks - Networks are vulnerable to unauthorized access, hacking, and cyber-attacks, which can lead to data breaches and theft of sensitive information. 
  6. Malware Spread - A single infected computer can easily spread viruses and other malware to all other connected devices on the network. 
  7. Privacy Concerns - Network administrators may monitor user activity for security and performance, raising concerns about personal privacy and potential surveillance. 
  8. Single Point of Failure - If a central server or critical network device fails, the entire network can go down, making resources unavailable to all users. 
  9. Bandwidth Limitations - Insufficient bandwidth can lead to network congestion, slower data transfer rates, and reduced productivity for all users. 
  10. Dependency - Users become dependent on the network and its connected resources; a failure can render users and their work useless. 
  11. Health Issues - Over-reliance on computer networks for entertainment and information can lead to excessive usage and potentially addictive behaviours. 
  12. Compatibility Issues - Hardware and software from different vendors may not always function together seamlessly, creating compatibility problems.

Uses of Computer Network

Computer networks have become invaluable to organizations as well as individuals. Some of its main uses are as follows:

  1. Information and Resource Sharing: Computer networks allow organizations having units which are placed apart from each other, to share information in a very effective manner. Programs and software in any computer can be accessed by other computers linked to the network. It also allows sharing of hardware equipment, like printers and scanners among varied users.
  2. Retrieving Remote Information: Through computer networks, users can retrieve remote information on a variety of topics. The information is stored in remote databases to which the user gains access through information systems like the World Wide Web.
  3. Speedy Interpersonal Communication: Computer networks have increased the speed and volume of communication like never before. Electronic Mail (email) is extensively used for sending texts, documents, images, and videos across the globe. Online communications have increased by manifold times through social networking services.
  4. E-Commerce: Computer networks have paved way for a variety of business and commercial transactions online, popularly called e-commerce. Users and organizations can pool funds, buy or sell items, pay bills, manage bank accounts, pay taxes, transfer funds and handle investments electronically.
  5. Highly Reliable Systems: Computer networks allow systems to be distributed in nature, by the virtue of which data is stored in multiple sources. This makes the system highly reliable. If a failure occurs in one source, then the system will still continue to function and data will still be available from the other sources.
  6. Cost–Effective Systems: Computer networks have reduced the cost of establishment of computer systems in organizations. Previously, it was imperative for organizations to set up expensive mainframes for computation and storage. With the advent of networks, it is sufficient to set up interconnected personal computers (PCs) for the same purpose.

Network Criteria

A network must be able to meet a certain number of criteria. The most important of these are performance, reliability, and security.

  1. Performance - Performance can be measured in many ways, including transit time and response time. Transit time is the amount of time required for a message to travel from one device to another. Response time is the elapsed time between an inquiry and a response. The performance of a network depends on a number of factors, including the number of users, the type of transmission medium, the capabilities of the connected hardware, and the efficiency of the software. 

Performance is often evaluated by two networking metrics: throughput and delay. We often need more throughputs and less delay. However, these two criteria are often contradictory. If we try to send more data to the network, we may increase throughput but we increase the delay because of traffic congestion in the network

  1. Reliability - In addition to accuracy of delivery, network reliability is measured by the frequency of failure, the time it takes a link to recover from a failure, and the network's robustness in a catastrophe.
  2. Security - Network security issues include protecting data from unauthorized access, protecting data from damage and development, and implementing policies and procedures for recovery from breaches and data losses.

Types of Networks

A network consists of two or more computers that are linked in order to share resources (such as printers and CDs), exchange files, or allow electronic communications. The computers on a network may be linked through cables, telephone lines, radio waves, satellites, or infrared light beams.

Depending upon the geographical area covered by a network, it is classified as:

  1. Local Area Network (LAN)
  2. Metropolitan Area Network (MAN)
  3. Wide Area Network (WAN)
  4. Personal Area Network (PAN)
  5. Wireless Network
  6. Inter Network

1. Local Area Network (LAN) –

A LAN is a network that is used for communicating among computer devices, usually within an office building or home. LAN’s enable the sharing of resources such as files or hardware devices that may be needed by multiple users. It is limited in size, typically spanning a few hundred meters, and no more than a mile. Requires little wiring, typically a single cable connecting to each device.

It has lower cost compared to MAN’s or WAN’s. LAN’s can be either wired or wireless. Twisted pair, coax or fibre optic cable can be used in wired LAN’s.

Every LAN uses a protocol – a set of rules that governs how packets are configured and transmitted. Nodes in a LAN are linked together with a certain topology. These topologies include: Bus, Ring and Star topologies. LANs are capable of very high transmission rates (100s Mb/s to G b/s).

Applications of LAN:

Some common applications of LAN are: -

  1. Connected Devices (Home Network) - Smartphones, computers, smart TVs, and printers can all communicate with each other and share an internet connection within a single home. Smart home devices like lights, thermostats, and security cameras are connected to the home LAN. 
  2. Resource Sharing (Office Network) - LANs enable employees to share expensive resources like laser printers, software licenses, and network servers. They facilitate file sharing, centralized data storage, and access to local applications, improving teamwork and productivity. 
  3. Resource Access (Education Network) - LANs connect classrooms, libraries, and administrative offices to share educational materials, databases, and internet access. They provide a high-speed backbone for universities and schools to serve thousands of users and devices. 

2. Metropolitan Area Network (MAN) –

A metropolitan area network (MAN) is a large computer network that usually spans a city or a large campus. A MAN is optimized for a larger geographical area than a LAN, ranging from several blocks of buildings to entire cities.

A MAN might be owned and operated by a single organization, but it usually will be used by many individuals and organizations. It often acts as a high speed network to allow sharing of regional resources; typically covers an area of between 5 and 50 km diameter.

Examples of MAN: Telephone company network that provides a high speed DSL to customers and cable TV network.

Applications of MAN:

Some common applications of MAN are: -

  1. Connecting Businesses and Branches - Businesses use MANs to connect their various offices, stores, and data centres within a metropolitan area, facilitating efficient data transfer, communication, and resource sharing.
  2. City-Wide Connectivity - MANs provide high-speed internet and connectivity services to residents and businesses within a metropolitan area. 
  3. Government and Public Services - They are used by government agencies for public safety, traffic management, communication between departments, and sharing administrative data, enhancing city services. 

3. Wide Area Network (WAN) –

WAN covers a large geographic area such as country, continent or even whole of the world. A WAN is two or more LANs connected together. The LANs can be many miles apart. To cover great distances, WANs may transmit data over leased high-speed phone lines or wireless links such as satellites. Multiple LANs can be connected together using devices such as bridges, routers, or gateways, which enable them to share data. The world's most popular WAN is the Internet.

Applications of WAN:

Some common applications of WAN are: -

  1. Intra Company Communication and Resource Sharing - WANs allow employees in different offices to communicate via email, instant messaging, and video conferencing. Employees can access shared resources like printers, file servers, and databases across different locations. 
  2. Connecting Remote Employees - WANs enable employees working remotely (e.g., from home or on the road) to securely access company resources and applications. VPNs create secure connections over the public internet, allowing remote users to connect to the company's private network. 
  3. Disaster Recovery and Business Continuity - WANs allow businesses to back up data to offsite locations, ensuring data availability in case of a disaster. If a local office experiences a disruption, employees can relocate to a different site and continue working using the WAN to access resources.

4. Personal Area Network (PAN) –

A PAN is a network that is used for communicating among computers and computer devices (including telephones) in close proximity of around a few meters within a room. It can be used for communicating between the devices themselves, or for connecting to a larger network such as the internet. PAN’s can be wired or wireless.

Applications of PAN:

Some applications of PAN are: -

  1. Wearable Technology - Syncing smartwatches and fitness trackers to smartphones to monitor health and activity. 
  2. IN-Car Systems - Linking a smartphone to the vehicle's audio and communication system for hands-free calling and music. 
  3. Data Sharing - Transferring files or information between a smartphone and a tablet or laptop. 
  4. Entertainment - Connecting a gaming console or PC to wireless headphones for a personal audio experience.

5. Wireless Network –

It is the fastest growing segment of computer. They are becoming very important in our daily life because wind connections are not possible in cars or aeroplane. We can access Internet at any place avoiding wire related troubles. These can be used also when the telephone systems get destroyed due to some calamity/disaster. WANs are really important now-a-days.

6. Inter Network –

When we connect two or more networks then they are called internetwork or internet. We can join two or more individual networks to form an internetwork through devices like routers gateways or bridges.

Client/Server Network

In a client/server network, a number of network clients or workstations request resources or services from the network. One or more network servers manage and provide these resources or services. The clients are computers that depend on the server for data and software. Network servers are also referred to as computer servers or simply servers. Sometimes a server is described in terms of the specific service it provides, such as e-mail server, print server or storage server. Some servers, however, can provide all these services.

  • Server - Servers are typically computers with more processing speed, memory and hard disk space than a regular desktop computer. The network servers run their own operating system that manages the various network tasks as well as services that run on the network. Depending on the need for network storage and services, a single network may only use one or a large number of servers.
  • Clients - Clients are hardware devices which provide end users with access to data and services on the server. You can use these devices more or less independently. For example, you can open up software applications, create and edit documents and save files on the local storage medium, such as a hard disk. However, in a typical client/server network, a number of essential tasks are not performed by the client alone.

Some examples are: -

  1. A printer is connected to the network - to print a document, the client sends a print request to the server.
  2. All the e-mail messages are stored on the server - the client is used to view and manage the messages but does not store the actual files.
  3. Very large databases are stored on the server - the client accesses these without copying them onto the local hard drive.

Workgroup

In computer networking, a workgroup is a collection of computers on a local area network (LAN) that share common resources and responsibilities. The term is most commonly associated with Microsoft Windows workgroups but also applies to other environments. Windows workgroups can be found in homes, schools, and small businesses.

Microsoft Windows workgroups organize PCs as peer-to-peer local networks that facilitate easier sharing of files, internet access, printers, and other local network resources.

Each computer that's a member of the group can access the same resources being shared by the others, and in turn, can share its own resources if configured to do so.

Host

A host (also known as "network host") is a computer or other device that communicates with other hosts on a network. Hosts on a network include clients and servers, that send or receive data, services or applications.

System Administrators

Network and computer systems administrators are responsible for the day-to-day operation of these networks. They organize, install, and support an organization's computer systems, including local area networks (LANs), wide area networks (WANs), network segments, intranets, and other data communication systems.