What is Network Connectivity?

Network connectivity describes the process of interconnecting various parts of the network together. There are various devices available which are used to connect various parts of the network namely routers, switches, gateways etc. Various technologies such as cloud computing, big data, and the internet of things are highly dependent on network connectivity. It is very important for enterprises, businesses or companies because network connectivity enables them to access, collect, share, and utilize data across their organization.

Network topologies include hub, linear, tree, and star designs, each of which is set up differently to promote connectivity between computers or devices. In terms of network connectivity, each one has its own set of advantages and disadvantages. As they look at an ever-increasing diversity of networks and the ways networking parts fit together, IT professionals, particularly network administrators and network analysts, talk about connection as one piece of the network puzzle.

Types of network connections

Point-to-point connection : It represents the direct communication link connecting exactly two devices. For example, the connection between two walkie talkie phones. PPP (Point-to-Point Protocol) is used to achieve communication between the two devices which are connected directly. It provides authentication, encryption and compression during transmission.

Point-to-multipoint connection: It represents the link between a device and multiple devices. It enables a device to communicate with multiple devices simultaneously. For example, broadcasting done by tv or radio stations.

Types of network topology

Network topology is the arrangement of nodes (devices) and connecting lines (wires) that interconnect those devices. The various network topologies are:

Mesh topology

In the mesh topology, every device in the network is connected to every other device using a dedicated communication link.

• Suppose if there are n devices connected to each other, then every device must have n-1 ports to connect to the remaining n-1 devices. For example, in the above diagram 5 computer systems are connected to each other to form a mesh topology. Every computer connects to 4 other computers. Hence, the number of ports required by each computer is 4 and the total number of ports is given by $5\times 4=20$. Therefore, it is clear that, in a mesh topology $n\times (n-1)$ ports are required.

• If n devices are connected to form a mesh topology, then total number of links required is given by nC2 which is $\raisebox{1ex}{$n(n-1)$}\!\left/ \!\raisebox{-1ex}{$2$}\right.$. In the above diagram, n=5 and therefore, the total number of links required is given by $\raisebox{1ex}{$5\times 4$}\!\left/ \!\raisebox{-1ex}{$2$}\right.$ = 10.

Star Topology

In a star topology, all devices are connected to the hub through a cable. The hub is nothing but a central node and all devices are connected to the central hub. There are 2 types of hubs: active hub and passive hub. The active hub is intelligent in nature such as a repeater but the passive hub is not intelligent in nature such as broadcasting devices.

Bus topology

In a bus topology, every computer and network system are connected to a single wire. The bus connectivity has multiple-points connection. It follows unidirectional transmission, which means it transmits data from one end of the bus to another end. It never follows bi-directional rule. It has non-robust nature because if the backbone of the network fails then the whole connection will crash.

Ring Topology

A ring topology is a network setup that creates a circular data channel by connecting devices in a circle. In a ring network, each networked device is connected to two others on either sides.

Packets of data pass from one device to the next in a ring network until they reach their destination. A ring network can be unidirectional or bi-directional in nature. In a unidirectional ring network, data flows in only one direction. In a bi-directional ring network, data can flow in both clockwise and anti-clockwise directions.

Tree Topology

A tree topology is a form of structure in which several interconnected pieces are grouped in the shape of a tree's branches. Tree topologies, for example, are widely used to organize computers in a business network or data in a database.

There can only be one link between any two connected nodes in a tree structure. Tree topologies create a natural parent and child hierarchy because each node can only have one common link.

Types of network

The network connectivity designed over the area are of three types namely LAN, MAN and WAN. They differ by the amount of geographical area they span, type of transmission media used and the data rate that is supported.

LAN (Local Area Network)

A local area network (LAN) is used to interconnect a group of devices within a building, business, or home. A LAN can be small or large, ranging from a single-user home network to an enterprise network in an office or school with thousands of users and devices. In this network connectivity, the personal computers and workstations are connected through the LAN and share data or information with each other. They are connected by a switch, or stack of switches using a private addressing scheme TCP/IP protocol.

MAN (Metropolitan Area Network)

A metropolitan area network (MAN) is similar to a local area network (LAN), except that it covers an entire city, university, or other municipal or organisational territory. Multiple LANs are connected to form MANs. As a result, MANs are larger than LANs but smaller than wide area networks (WANs), which covers an enormous geographic areas and can connect users all over the world.

MANs are often very efficient and can communicate quickly across high-speed carriers like fiber optic cables. The advent of wireless and subsequent networking technologies, on the other hand, has resulted in a profusion of signal delivery modalities throughout a larger MAN area. It is measured in Mbps.

WAN (Wide Area Network)

A Wide Area Network (WAN) is a type of telecommunications network that spans a vast geographic area and is mostly used for computer networking. Leasing telecommunication circuits are frequently used to build wide area networks. This is highly expensive technology and provides better internet speed to LAN and MAN. There are two types of WAN switches namely, switched WAN and Point-to-Point WAN.

Common Mistakes

LAN, WAN and MAN not only differs by size but also by ownership. LAN is privately owned. MAN is usually owned by huge organization whereas WAN uses a public network to interconnect geographically distributed networks.

Concept and Applications

This topic is significant in the professional exams for both graduate and postgraduate courses, especially for:

• Bachelor of Technology in Computer Science
• Bachelor of Technology in Information Technology
• Master of Technology in Computer System and Networking

Related Concepts

• Ethernet
• Frame relay
• WLAN

Practice Problems

Q1- What is star topology?

1. many computers are connected through a single cable
2. many computer networks are connected through a hub
3. computers are connected to each other
4. None

Correct answer - Option 2

Explanation: Many computer networks are connected to a central node called a hub.

Q2- The combination of two or more interconnected network is called-

1. WAN
2. MAN
3. LAN
4. Internetwork

Correct answer - Option 4

Explanation: Inter-connected collection of network is referred to as an internetwork.

Q3- The network that provides high speed connectivity of transmission over longer distances is _______

1. MAN
2. LAN
3. WAN
4. None of the above

Correct answer - Option 3

Explanation: WAN provides connection across the world.

Q4- Common used LAN protocol is _________

1. Ethernet
2. Frame relay
3. X.25
4. PPP

Correct answer - Option 1

Explanation: Ethernet is the most commonly used LAN transmission technology.

Q5- A device that interconnects various heterogeneous networks is ____________

1. Switch
2. Gateway
3. Hub
4. All of these

Correct answer-Option 2

Explanation: Gateway is used interconnect heterogeneous networks which differ in various aspects.