NETWORKING AND INTERNET

Computer Networking: A computer network is a set of connected computers. Computers on a network are called nodes. The connection between computers can be done by a cabling, the Ethernet cable, or wirelessly through radio waves. Connected computers can share resources, like access to the internet, printers, file servers and others.

 

Components:

  1. Server- A computer designed to process requests and deliver data to other (client) computers over a local network or the internet.
  2. Receiver- Hardware module or device used to receive signals.
  3. Channel- A physical connection between server and reciever.

 

Transmission channel

Simplex Channels- Simplex is a communication channel that operates in one direction at a time. Half Duplex Channel- A Half duplex channel can send and receive data, but not at the same time. Full Duplex Channel- Refers to the transmission of data in two directions simultaneously.

 

Types of data communication medium

  • Standard telephone line
  • Microwave transmission
  • Optical fibers
  • Coaxial cable
  • Satellite communication

 

Network devices

  1. Network adaptor is a device that enables a computer to connect with the other computer/using MAC Address.
  2. Hub is a device that splits a network connection into multiple computers.
  3. Switch is a telecommunication device grouped as one of computer network components.
  4. Cable is one way of transmission medium which can transmit communication signals.
  5. Repeaters are used to re generate or replicate signals that are weekend or distorted by transmission over long distances.
  6. Bridge is used to connect two LANs with the same standard but using different types of cables.
  7. Routers are used to join multiple computer networks together via either wired or wireless connections.
  8. Gateways are a key stopping point for data on its way to or from other networks.
  9. MODEM - Modulator-Demodulator electronic device that allows computers to communicate over telephone wires or cable-TV cable.

 

TYPES OF NETWORK

  1. Local Area Network (LAN) - A computer network that link devices within a building or group of adjacent Example star line, ring LAN, bus LAN.
  2. Wide Area Network (WAN) - A computer network in which the computers connected may be far apart. 
  3. Metropolitan Area Network (MAN) - A Metropolitan Area Network (MAN) is a network that interconnects users with computer resources in Geographic area or region larger than that covered by even a LAN but smaller than the area covered by Example- Public Networks, Public Switched Telephone Networks (PSTN), Public Service Digital Network (PSDN).
  4. Integrated Services Digital Network (ISDN) is a set of communication standards of simultaneous digital transmission of voice, video, data.

 

NETWORK TOPOLOGY

  1. Mesh Topology- Mesh is a network topology in which devices are connected with many redundant interconnections between network nodes. 
  2. Star Topology- Star topology is a network topology where each individual piece of a network is attached to a central node.
  3. Ring Topology- Ring topology refers to a specific kind of network setup in which devices are connected in a ring and pass information to each other according to their adjacent in the ring structure.
  4. Bus Topology- Bus topology is a specific kind of network topology in which all of the various devices in the network are connected to a single cable or line.
  5. Tree Topology- It is a combination characteristics of linear, bus and star topology.

 

OSI MODEL

OSI: The open system interconnection model (OSI Model) is a conceptual model that characterizes and standardizes the communication functions of a telecommunication of computing system without regard of their underlying internal structure and Technology.

 

7 layers of OSI model

  1. Physical Layer- The physical layer is the first layer of the OSI model that deals with bit level transmission between different devices and supports electrical or mechanical interfaces connecting to the physical medium for synchronised communication.
  2. Data Link Layer- The data link layer is the second layer of OSI This layer is the protocol layer that transfers the data in the form of frames between adjacent network nodes in a wide area network or between nodes on the same Local area network segment.
  3. Network Layer- The network layer is the third level of the OSI model and the layer that provide the data routing paths for network Data is transferred in the form of packets biological network path in an ordered format controlled by the network layer.
  4. Transport Layer- The transport layer is the layer in the OSI model responsible for end-to-end communication (in the form of segments) over a It provides logical communication between application processes running on different host within a layered architecture of protocols and other network components.
  5. Session Layer- In the OSI model, the session layer is the fifth layer which controls the connections between multiple computers. The session layer tracks the dialogues between computers, which are also called sessions.
  6. Presentation Layer- The presentation layer is the 6 layer in OSI It is used to present data to the application layer (layer 7) in an accurate, well defined and standardized format. The presentation layer is sometimes called the syntax layer.
  7. Application Layer- The application layer is a layer in the OSI model and in the TCP/IP protocol It consists of protocols that focus on process-to-process communication across an IP Network and provides a firm communicate and end-user services.

 

DATA TRANSMISSION

  1. NIC-Network Interface Card: Network Interface Card (NIC) is a computer circuit board or card that is installed in a computer so that it can be connected to a network.
  2. Wireless Technology- Wireless communications is a type of data, a wireless signal through wireless communication Technologies and device.

 

  • Protocol- It is a set of rules and Standards which is used by computers to exchange data or information with each other across a network.
  • Nodes- It is a connect point where data transmission and redistribution of data starts.
  • TCP/IP (Transmission Control Protocol/Internet Protocol) - Basic communication language or protocol of the internet. IPV4 - 32 bits numeric address and IPV6 - 128 bits hexadecimal address
  • File Transfer Protocol (FTP) is a standard network protocol used to transfer computer files between a client and server on a computer network.
  • Internet Service Provider (ISP) is an organization that provides services for accessing and using the internet.
  • Network Service Provider (NSP) is a company that provides backbone services to an internet service provider (ISP).
  • Web server is a program that uses HTTP (Hyper Text Transfer Protocol) to serve the files that form web pages to the users in response to their requests which are forwarded by their computers’ HTTP clients.
  • Website is a collection of related web pages, including multimedia content, typically identified with a common domain name. 
  • Homepage is the introductory page of a website. 
  • Hyperlink is a word, phrase or image that you can click on to jump to a new document or a new section within the current document. 
  • Hyper Text Transfer Protocol (HTTP) is an application protocol for distributed, collaborative, hypermedia information systems.
  • URL (Uniform Resource Locator) is a form of URI and is a standardized naming convention for addressing documents accessible over the internet and intranet.


INTERNET

  1. Internet- A global computer network providing a variety of Information and Communication Consisting of interconnected networks using standardised Communication protocols.
  2. Modem- A combined device for modulation and demodulation, for example, between the digital data of a computer and the analogue signal of a telephone line.
  3. Web browser- Web browser is a software application used to locate, retrieve and display content on the World Wide Web including web pages, images and video.