Week-2-Computer-Network.pdf

NETWORKING 1: WEEK 2 Computer Network OBJECTIVE: At the end of the lesson, the learner should be able to: 1. Explain the different types of computer network. 2. Classify LAN/WAN 3. Explain the different topologies 4. Explain the different mode of transmission Computer Network A Comput...

NETWORKING 1: WEEK 2 Computer Network OBJECTIVE: At the end of the lesson, the learner should be able to: 1. Explain the different types of computer network. 2. Classify LAN/WAN 3. Explain the different topologies 4. Explain the different mode of transmission Computer Network A Computer Network is a group of computers linked to each other that enables the computer to communicate with another computer and share their resources, data, and applications. Computer Network A computer network can be categorized by their size. A computer network is mainly of four types: 1. LAN(Local Area Network) 2. PAN(Personal Area Network) 3. MAN(Metropolitan Area Network) 4. WAN(Wide Area Network) 4 Types of Computer Network 1. LAN (Local Area Network) Local Area Network is a group of computers connected to each other in a small area such as building, office. LAN is used for connecting two or more personal computers through a communication medium such as twisted pair, coaxial cable, etc. 4 Types of Computer Network 1. LAN (Local Area Network) It is less costly as it is built with inexpensive hardware such as hubs, network adapters, and ethernet cables. The data is transferred at an extremely faster rate in Local Area Network. Local Area Network provides higher security. 4 Types of Computer Network 2. PAN (Personal Area Network) Personal Area Network is a network arranged within an individual person, typically within a range of 10 meters. Personal Area Network is used for connecting the computer devices of personal use is known as Personal Area Network. 4 Types of Computer Network 2. PAN (Personal Area Network) Thomas Zimmerman was the first research scientist to bring the idea of the Personal Area Network. Personal Area Network covers an area of 30 feet. Personal computer devices that are used to develop the personal area network are the laptop, mobile phones, media player and play stations. 4 Types of Computer Network Examples of Personal Area Network: 1. Body Area Network: Body Area Network is a network that moves with a person. For example, a mobile network moves with a person. Suppose a person establishes a network connection and then creates a connection with another device to share the information. 4 Types of Computer Network Examples of Personal Area Network: 2. Offline Network: An offline network can be created inside the home, so it is also known as a home network. A home network is designed to integrate the devices such as printers, computer, television but they are not connected to the internet. 3. Small Home Office: It is used to connect a variety of devices to the internet and to a corporate network using a VPN 4 Types of Computer Network 3. MAN (Metropolitan Area Network) A metropolitan area network is a network that covers a larger geographic area by interconnecting a different LAN to form a larger network. Government agencies use MAN to connect to the citizens and private industries. 4 Types of Computer Network 3. MAN (Metropolitan Area Network) In MAN, various LANs are connected to each other through a telephone exchange line. The most widely used protocols in MAN are RS- 232, Frame Relay, ATM, ISDN, OC-3, ADSL, etc. It has a higher range than Local Area Network (LAN). 4 Types of Computer Network Uses of Metropolitan Area Network: MAN is used in communication between the banks in a city. It can be used in an Airline Reservation. It can be used in a college within a city. It can also be used for communication in the military. 4 Types of Computer Network 4. WAN (Wide Area Network) A Wide Area Network is a network that extends over a large geographical area such as states or countries. A Wide Area Network is quite bigger network than the LAN. 4 Types of Computer Network 4. WAN (Wide Area Network) A Wide Area Network is not limited to a single location, but it spans over a large geographical area through a telephone line, fiber optic cable or satellite links. The internet is one of the biggest WAN in the world. A Wide Area Network is widely used in the field of Business, government, and education. 4 Types of Computer Network Examples of Wide Area Network: Mobile Broadband: A 4G network is widely used across a region or country. Last mile: A telecom company is used to provide the internet services to the customers in hundreds of cities by connecting their home with fiber. Private network: A bank provides a private network that connects the 44 offices. This network is made by using the telephone leased line provided by the telecom company. Internetwork An internetwork is defined as two or more computer network LANs or WAN or computer network segments are connected using devices, and they are configured by a local addressing scheme. This process is known as internetworking. Internetwork An interconnection between public, private, commercial, industrial, or government computer networks can also be defined as internetworking. An internetworking uses the internet protocol. The reference model used for internetworking is Open System Interconnection (OSI). Types of Internetwork: 1. Extranet: An extranet is a communication network based on the internet protocol such as Transmission Control protocol and internet protocol. It is used for information sharing. The access to the extranet is restricted to only those users who have login credentials. An extranet is the lowest level of internetworking. It can be categorized as MAN, WAN or other computer networks. An extranet cannot have a single LAN, at least it must have one connection to the external network. Types of Internetwork: 2. Intranet: An intranet is a private network based on the internet protocol such as Transmission Control protocol and internet protocol. An intranet belongs to an organization which is only accessible by the organization's employee or members. The main aim of the intranet is to share the information and resources among the organization employees. An intranet provides the facility to work in groups and for teleconferences. Intranet advantages: 1. Communication: It provides a cheap and easy communication. An employee of the organization can communicate with another employee through email, chat. 2. Time-saving: Information on the intranet is shared in real time, so it is time-saving. 3. Collaboration: Collaboration is one of the most important advantage of the intranet. The information is distributed among the employees of the organization and can only be accessed by the authorized user. Types of Network Topologies Topology defines the structure of the network of how all the components are interconnected to each other. There are two types of topology: physical and logical topology. Types of Network Topologies Types of Network Topologies Two Types of Topology: 1. Physical topology is the geometric representation of all the nodes in a network. 2. Logical topology refers to the abstract representation of how data flows and is transmitted within a network, independent of its physical layout. Types of Network Topologies 1. Point to Point (P2P) Point-to-point topology is the easiest of all the network topologies. In this method, the network consists of a direct link between two computers. Types of Network Topologies Advantages of Point to Point Here are pros/benefits of using a bus topology: Cost of the cable is very less as compared to other topology, so it is widely used to build small networks. Famous for LAN network because they are inexpensive and easy to install. Types of Network Topologies It is widely used when a network installation is small, simple, or temporary. It is one of the passive topologies. So computers on the bus only listen for data being sent, that are not responsible for moving the data from one computer to others. Types of Network Topologies Disadvantages of Point to Point Here are the cons/drawbacks of bus topology: In case if the common cable fails, then the entire system will crash down. When network traffic is heavy, it develops collisions in the network. Whenever network traffic is heavy, or nodes are too many, the performance time of the network significantly decreases. Cables are always of a limited length. Types of Network Topologies 2. Bus Topology is designed in such a way that all the stations are connected through a single cable known as a backbone cable. Each node is either connected to the backbone cable by drop cable or directly connected to the backbone cable. The bus topology is mainly used in 802.3 (ethernet) and 802.4 standard networks. Types of Network Topologies The configuration of a bus topology is quite simpler as compared to other topologies. The backbone cable is considered as a "single lane" through which the message is broadcast to all the stations. The most common access method of the bus topologies is CSMA (Carrier Sense Multiple Access). Types of Network Topologies The configuration of a bus topology is quite simpler as compared to other topologies. The backbone cable is considered as a "single lane" through which the message is broadcast to all the stations. The most common access method of the bus topologies is CSMA (Carrier Sense Multiple Access). Types of Network Topologies 3.Ring Topology Ring topology is like a bus topology, but with connected ends. The node that receives the message from the previous computer will retransmit to the next node. The data flows in one direction, i.e., it is unidirectional. Types of Network Topologies 3.Ring Topology The data flows in a single loop continuously known as an endless loop. It has no terminated ends, i.e., each node is connected to other node and having no termination point. The data in a ring topology flow in a clockwise direction. Types of Network Topologies 3.Ring Topology The most common access method of the ring topology is token passing. Token passing: It is a network access method in which token is passed from one node to another node. Token: It is a frame that circulates around the network. Types of Network Topologies 3.Ring Topology The most common access method of the ring topology is token passing. Token passing: It is a network access method in which token is passed from one node to another node. Token: It is a frame that circulates around the network. Types of Network Topologies 4. Star Topology - is an arrangement of the network in which every node is connected to the central hub, switch or a central computer. The central computer is known as a server, and the peripheral devices attached to the server are known as clients. Types of Network Topologies 4. Star Topology Coaxial cable or RJ-45 cables are used to connect the computers. Hubs or Switches are mainly used as connection devices in a physical star topology. Star topology is the most popular topology in network implementation. Types of Network Topologies 5. Tree topology- combines the characteristics of bus topology and star topology. A tree topology is a type of structure in which all the computers are connected with each other in hierarchical fashion. Types of Network Topologies 5. Tree topology The top-most node in tree topology is known as a root node, and all other nodes are the descendants of the root node. There is only one path exists between two nodes for the data transmission. Thus, it forms a parent-child hierarchy. Types of Network Topologies 6. Mesh topology is an arrangement of the network in which computers are interconnected with each other through various redundant connections. There are multiple paths from one computer to another computer. It does not contain the switch, hub or any central computer which acts as a central point of communication. Types of Network Topologies 6. Mesh topology The Internet is an example of the mesh topology. Mesh topology is mainly used for WAN implementations where communication failures are a critical concern. Mesh topology is mainly used for wireless networks. Mesh topology can be formed by using the formula: Number of cables = (n*(n-1))/2; ***Where n is the number of nodes that represents the network. Types of Network Topologies Mesh topology is divided into two categories: 1. Full Mesh Topology: In a full mesh topology, each computer is connected to all the computers available in the network. 2. Partial Mesh Topology: In a partial mesh topology, not all but certain computers are connected to those computers with which they communicate frequently. Types of Network Topologies 7. Hybrid Topology The combination of various different topologies is known as Hybrid topology. A Hybrid topology is a connection between different links and nodes to transfer the data. Types of Network Topologies 7. Hybrid Topology When two or more different topologies are combined together is termed as Hybrid topology and if similar topologies are connected with each other will not result in Hybrid topology. For example, if there exist a ring topology in one branch of ICICI bank and bus topology in another branch of ICICI bank, connecting these two topologies will result in Hybrid topology. Types of Network Topologies Advantages of Hybrid Topology Reliable Scalable Flexible Effective Disadvantages of Hybrid topology Complex design. Costly infrastructure Types of Network Topologies Transmission modes The way in which data is transmitted from one device to another device is known as transmission mode. The transmission mode is also known as the communication mode. Each communication channel has a direction associated with it, and transmission media provide the direction. Therefore, the transmission mode is also known as a directional mode. The transmission mode is defined in the physical layer. Thank you for listening Question and Answer