A network allows interconnected computers to exchange information. The document discusses different types of networks including ARPANET, the Internet, and the Interspace. It defines key networking concepts such as autonomous computers, interconnection, protocols, gateways, and backbones. The document also summarizes different types of transmission media including twisted pair cables, coaxial cable, fiber optic cable, microwave, and compares their characteristics. It describes networking devices like hubs, switches, repeaters, and bridges.
This document discusses fast and secure protocols for data transmission. It begins by defining what a protocol is and provides examples like HTTP and FTP. It then explains TCP and how it enables connection and guaranteed delivery of packets in order. FASP is introduced as an innovative file transfer technology that can achieve speeds hundreds of times faster than TCP/HTTP with guaranteed delivery times regardless of file size or network conditions. Benefits of FASP include maximum speed, security, and less packet loss compared to TCP. FASP is concluded to be a next generation technology that can provide optimal data transfer over any network.
Tunneling is a protocol that allows for the secure movement of data from one network to another
Tunneling involves allowing private network communications to be sent across a public network, such as the Internet
In tunneling, the data are broken into smaller pieces called packets as they move along the tunnel for transport
As the packets move through the tunnel, they are encrypted and another process called encapsulation occurs
This document provides an overview of wireless sensor networks. It discusses wireless communication technologies, the need for wireless communication, and defines wireless sensor networks. It describes the characteristics, architecture, operating systems, applications, and technical challenges of wireless sensor networks. Finally, it discusses some companies that manufacture wireless sensor network products, including Cisco, IBM, and Libelium.
A computer network allows computers to exchange data by connecting computing devices. There are different types of networks including ring, bus, star, and tree networks. A bus network connects nodes in a linear sequence using a single cable or bus. It has advantages like easy connection and less cable required but disadvantages like the entire network failing if the main cable is damaged. In a bus network, all nodes receive all traffic and each station has equal priority to transmit.
Deauthentication Attack with Node MCU & Esp8266Akash Thakur
This document describes how to build a WiFi deauthentication attack tool using a Node MCU ESP 8266 chip. It explains that deauthentication attacks work by spoofing management frames to disconnect devices from access points. While 802.11w aimed to encrypt these frames, compatibility issues have prevented its adoption. The document then provides instructions for setting up the Node MCU ESP 8266 chip to execute deauthentication attacks.
This document compares the 1st through 4th generations of wireless technology. 1G was analog and focused on voice. 2G introduced digital transmission and data services. 3G brought increased speeds and applications like video calling. 4G will provide speeds from 100 Mbps to 1 Gbps for broadband access anywhere. It analyzes the strengths, weaknesses, opportunities, and threats for each generation.
The document is a project report on an ATM management system created by three students. It includes sections on the abstract, introduction, system specifications, project description, feasibility study and code implementation. The system allows customers to check balances, withdraw and deposit cash through an ATM interface using a PIN for authentication. It aims to simplify banking transactions and reduce paperwork compared to a manual process.
This is an internship presentation that I created as part of the internship curriculum, you can use this presentation for a web developer internship presentation that you might need to give in your college.
If you want some animation please see Internship Presentation 2 that I uploaded.
It has basic web developer tools explained like Git, HTML, Java etc.
This document discusses fast and secure protocols for data transmission. It begins by defining what a protocol is and provides examples like HTTP and FTP. It then explains TCP and how it enables connection and guaranteed delivery of packets in order. FASP is introduced as an innovative file transfer technology that can achieve speeds hundreds of times faster than TCP/HTTP with guaranteed delivery times regardless of file size or network conditions. Benefits of FASP include maximum speed, security, and less packet loss compared to TCP. FASP is concluded to be a next generation technology that can provide optimal data transfer over any network.
Tunneling is a protocol that allows for the secure movement of data from one network to another
Tunneling involves allowing private network communications to be sent across a public network, such as the Internet
In tunneling, the data are broken into smaller pieces called packets as they move along the tunnel for transport
As the packets move through the tunnel, they are encrypted and another process called encapsulation occurs
This document provides an overview of wireless sensor networks. It discusses wireless communication technologies, the need for wireless communication, and defines wireless sensor networks. It describes the characteristics, architecture, operating systems, applications, and technical challenges of wireless sensor networks. Finally, it discusses some companies that manufacture wireless sensor network products, including Cisco, IBM, and Libelium.
A computer network allows computers to exchange data by connecting computing devices. There are different types of networks including ring, bus, star, and tree networks. A bus network connects nodes in a linear sequence using a single cable or bus. It has advantages like easy connection and less cable required but disadvantages like the entire network failing if the main cable is damaged. In a bus network, all nodes receive all traffic and each station has equal priority to transmit.
Deauthentication Attack with Node MCU & Esp8266Akash Thakur
This document describes how to build a WiFi deauthentication attack tool using a Node MCU ESP 8266 chip. It explains that deauthentication attacks work by spoofing management frames to disconnect devices from access points. While 802.11w aimed to encrypt these frames, compatibility issues have prevented its adoption. The document then provides instructions for setting up the Node MCU ESP 8266 chip to execute deauthentication attacks.
This document compares the 1st through 4th generations of wireless technology. 1G was analog and focused on voice. 2G introduced digital transmission and data services. 3G brought increased speeds and applications like video calling. 4G will provide speeds from 100 Mbps to 1 Gbps for broadband access anywhere. It analyzes the strengths, weaknesses, opportunities, and threats for each generation.
The document is a project report on an ATM management system created by three students. It includes sections on the abstract, introduction, system specifications, project description, feasibility study and code implementation. The system allows customers to check balances, withdraw and deposit cash through an ATM interface using a PIN for authentication. It aims to simplify banking transactions and reduce paperwork compared to a manual process.
This is an internship presentation that I created as part of the internship curriculum, you can use this presentation for a web developer internship presentation that you might need to give in your college.
If you want some animation please see Internship Presentation 2 that I uploaded.
It has basic web developer tools explained like Git, HTML, Java etc.
paper presentation _ survey of wireless sensor netwrokejbyun77
The document discusses recent trends in wireless sensor network research, including an overview of different wireless sensor network technologies and applications. It also examines the role of middleware in supporting wireless sensor networks by providing common communication mechanisms and processing sensed data to abstract high-level information. Several existing middleware platforms and programming models are described that aim to achieve scalability, low power consumption, and efficient data aggregation and querying in wireless sensor networks.
Network interface cards connect computers to the network and differentiate networked computers from standalone computers. Hubs connect multiple devices but have no intelligence to direct traffic. Switches inspect packets and forward them only to the intended device, improving performance over hubs. Bridges segment large networks and monitor traffic to pass packets between the two sides. Routers select the best path for messages and can redirect traffic around busy sections. Gateways connect networks using different protocols by performing protocol conversions. Modems convert digital data to analog for telephone lines and provide connectivity to the Internet for small-to-medium networks.
This document summarizes the evolution of mobile networks from 2G to 4G. It describes the key technologies and capabilities of 2G (9.6 Kbps speed), 2.5G/GPRS (up to 115 Kbps), 3G (2 Mbps, increased bandwidth to 2GHz, supports video/GPS), LTE (200 active clients per 5MHz cell, up to 2Gbps speed), and 4G (formally approved in 2009 as IMT-Advanced, 2Gbps speed, improved coverage and capacity). Each generation brought increased speeds and bandwidth as well as new multimedia capabilities.
This document provides an overview of the evolution of cellular networks from traditional networks to broadband networks. It discusses early cellular networks including 2G technologies like GSM and CDMA networks. It then covers 3G and 3.5G broadband cellular networks including UMTS, HSPA, HSDPA and HSUPA which enabled higher data speeds. The document reviews the history and development of cellular standards over time from 1G to 4G networks and the increasing data capabilities they provided.
These slides cover a topic on B ISDN in Data Communication. All the slides are explained in a very simple manner. It is useful for engineering students & also for the candidates who want to master data communication & computer networking.
WIRELESS COMMUNICATION HANDWRITTEN NOTES FOR IPDhruv Aggarwal
UNIT – I
Introduction To Wireless Communication Systems: Evolution of mobile radio communications; examples of wireless comm. systems; paging systems; Cordless telephone systems; overview of generations of cellular systems, comparison of various wireless systems.
Introduction to Personal Communication Services (PCS): PCS architecture, Mobility management, Networks signaling. A basic cellular system, multiple access techniques: FDMA, TDMA, CDMA.
Introduction to Wireless Channels and Diversity: Fast Fading Wireless Channel Modeling, Rayleigh/Ricean Fading Channels, BER Performance in Fading Channels, Introduction to Diversity modeling for Wireless Communications
UNIT - II
2G Networks: Second generation, digital, wireless systems: GSM, IS_136 (D-AMPS), IS-95 CDMA. Global system for Mobile Communication (GSM) system overview: GSM Architecture, Mobility Management, Network signaling, mobile management, voice signal processing and coding. Spread Spectrum Systems- Cellular code Division Access Systems-Principle, Power Control, effects of multipath propagation on code division multiple access.
UNIT - III 2.5G Mobile Data Networks: Introduction to Mobile Data Networks, General Packet Radio Services (GPRS): GPRS architecture, GPRS Network nodes, EDGE, Wireless LANs, (IEEE 802.11), Mobile IP.
Third Generation (3G) Mobile Services: Introduction to International Mobile Telecommunications 2000 (IMT 2000) vision, Wideband Code Division Multiple Access (W-CDMA), and CDMA 2000, Quality of services in 3G, Introduction to 4G.
UNIT – IV
Wireless Local Loop (WLL): Introduction to WLL architecture, WLL technologies. Wireless personal area networks (WPAN): Blue tooth, IEEE 802.15, architecture, protocol stack. Wi-Max, introduction to Mobile Adhoc Networks.
Global Mobile Satellite Systems, Case studies of IRIDIUM and GLOBALSTAR systems.
This document provides an overview of GSM and MTNL. It discusses that MTNL was established in 1986 to improve telecom services in India. It then describes GSM as a mobile system using multiple radio cells, and discusses related technologies like GPRS and EDGE. The document outlines the key components of GSM including the SIM card, services provided, frequencies used, and the switching, radio, and operation subsystems. It also briefly discusses value-added services, network areas in GSM, and MTNL's joint ventures.
WAP (Wireless Application Protocol) is a standard for accessing information on mobile devices like phones. It uses WML (Wireless Markup Language) instead of HTML. WAP has a layered architecture including application, session, security, transaction, and transport layers. It allows access to the internet from mobile devices in a standardized way and is supported by most phone manufacturers and wireless networks.
Global System for Mobile (GSM) is a second generation cellular standard developed for voice services and data delivery using digital modulation. It has a network subsystem including components like the MSC, HLR, VLR, and AuC that handle call processing and subscriber information. The radio subsystem consists of BSCs controlling multiple BTSs to manage radio network access. GSM provides international roaming, high quality voice calls, and supports data services like SMS and fax in addition to voice.
The document summarizes the evolution of wireless networks from 1G to 4G. 1G networks used analog signals and standards like NMT, AMPS, and TACS. 2G introduced digital cellular and standards like GSM, CDMA, and IS-136. 2.5G provided upgrades like GPRS, EDGE, and CDMA2000 1x to support higher data rates. 3G networks supported broadband data and included W-CDMA and CDMA2000. 4G aims to provide fully integrated IP services with speeds over 100 Mbps.
sensors are what we experience the most in our life. they are even working in our body in different aspects. they may be as eyes, ears, skin, tongue etc. when we combine them they make a network. it may be a human sensor network. but i have shared something interesting about wireless sensor networks.
GPRS is a packet-based mobile data service that allows intermittent and bursty data transmissions over existing GSM networks. It uses packet switching to allocate resources only when needed, reducing connection times. GPRS supports flexible channel allocation and sharing of available resources between users. Common applications include standard IP-based services as well as GPRS-specific point-to-point and point-to-multipoint applications. Operators can generate revenue through new subscribers, services, applications, and increased data traffic under GPRS.
The document discusses the results of a study on the impact of climate change on global wheat production. Researchers found that rising temperatures will significantly reduce wheat yields across different regions of the world by the end of the century. Under a high emissions scenario, the study projects a global average decrease in wheat production of 6% by 2050, and a 17% decrease by 2100, threatening global food security.
This document compares hubs, switches, and routers. Hubs are the simplest devices that broadcast all incoming data to all ports. Switches are more intelligent and learn which devices are connected to each port to selectively broadcast data. Routers are the most advanced devices that can be programmed to understand and manipulate data, performing functions like network address translation to route packets between local networks and the internet.
The document discusses computer networks and their uses. Computer networks allow computers to exchange information and resources over various connection types. They are used in businesses to share files, printers, and databases between employees in different locations. Networks also enable communication functions like email and videoconferencing. Additionally, networks facilitate online shopping and transactions between businesses and consumers. While networks provide many benefits, they also introduce new social and security issues around topics like privacy, censorship, and cybercrime.
This document discusses advanced wireless communication technologies and their evolution over time to meet increasing data rate demands. It covers:
1) How wireless spectrum has become crowded as usage has increased, challenging engineers to develop technologies to achieve higher data rates within limited spectrum.
2) The evolution of mobile communication standards from 1G analog to 2G digital systems like GSM, and then 3G technologies like UMTS that supported data rates up to 384kbps.
3) Emerging 4G technologies aimed to support rates over 20Mbps using techniques like MIMO, adaptive modulation, and OFDM to more efficiently use available spectrum.
Mobile communication has evolved significantly since the first prediction in 1959 and demonstration in 1973. It allows users to stay connected anytime and anywhere through voice calls, SMS, and apps. The top manufacturers are Samsung, Apple, and others. While mobile technology provides many benefits, it also has environmental and human impacts that require consideration, such as the use of conflict minerals that fund violence. Future developments like 5G will further change mobile communication.
All the contents regarding SNMP basics and SNMP traps are mentioned in this presentation. Some of the additional things are using the latest version of SNMP v3. I have considered the extra details and added them in to this presentation to clear the confusions regarding SNMP traps and SNMP basics.
The working is also described in this presentation that how the SNMP works
This document discusses communication and its key aspects. It defines communication as the transfer of information from one person to another through transmitting ideas, thoughts, and values. The communication process involves a sender encoding a message and transmitting it through a channel to a receiver who decodes the message. There are different types of communication models, including the transactional process model which shows the back-and-forth interaction between a sender and receiver. Effective communication can be impacted by barriers related to the sender, receiver, or the situation.
The document provides guidance for students on the CBSE curriculum for Class XII Informatics Practices. It outlines the syllabus split up over the academic year, including topics covered in each month. The syllabus is divided into three units - Computer Networking and Open Source Concepts, Java Programming, and Relational Database Management Systems. The document also provides tables of contents and guidelines for theory and practical assignments to help students systematically learn the curriculum through a hands-on approach.
paper presentation _ survey of wireless sensor netwrokejbyun77
The document discusses recent trends in wireless sensor network research, including an overview of different wireless sensor network technologies and applications. It also examines the role of middleware in supporting wireless sensor networks by providing common communication mechanisms and processing sensed data to abstract high-level information. Several existing middleware platforms and programming models are described that aim to achieve scalability, low power consumption, and efficient data aggregation and querying in wireless sensor networks.
Network interface cards connect computers to the network and differentiate networked computers from standalone computers. Hubs connect multiple devices but have no intelligence to direct traffic. Switches inspect packets and forward them only to the intended device, improving performance over hubs. Bridges segment large networks and monitor traffic to pass packets between the two sides. Routers select the best path for messages and can redirect traffic around busy sections. Gateways connect networks using different protocols by performing protocol conversions. Modems convert digital data to analog for telephone lines and provide connectivity to the Internet for small-to-medium networks.
This document summarizes the evolution of mobile networks from 2G to 4G. It describes the key technologies and capabilities of 2G (9.6 Kbps speed), 2.5G/GPRS (up to 115 Kbps), 3G (2 Mbps, increased bandwidth to 2GHz, supports video/GPS), LTE (200 active clients per 5MHz cell, up to 2Gbps speed), and 4G (formally approved in 2009 as IMT-Advanced, 2Gbps speed, improved coverage and capacity). Each generation brought increased speeds and bandwidth as well as new multimedia capabilities.
This document provides an overview of the evolution of cellular networks from traditional networks to broadband networks. It discusses early cellular networks including 2G technologies like GSM and CDMA networks. It then covers 3G and 3.5G broadband cellular networks including UMTS, HSPA, HSDPA and HSUPA which enabled higher data speeds. The document reviews the history and development of cellular standards over time from 1G to 4G networks and the increasing data capabilities they provided.
These slides cover a topic on B ISDN in Data Communication. All the slides are explained in a very simple manner. It is useful for engineering students & also for the candidates who want to master data communication & computer networking.
WIRELESS COMMUNICATION HANDWRITTEN NOTES FOR IPDhruv Aggarwal
UNIT – I
Introduction To Wireless Communication Systems: Evolution of mobile radio communications; examples of wireless comm. systems; paging systems; Cordless telephone systems; overview of generations of cellular systems, comparison of various wireless systems.
Introduction to Personal Communication Services (PCS): PCS architecture, Mobility management, Networks signaling. A basic cellular system, multiple access techniques: FDMA, TDMA, CDMA.
Introduction to Wireless Channels and Diversity: Fast Fading Wireless Channel Modeling, Rayleigh/Ricean Fading Channels, BER Performance in Fading Channels, Introduction to Diversity modeling for Wireless Communications
UNIT - II
2G Networks: Second generation, digital, wireless systems: GSM, IS_136 (D-AMPS), IS-95 CDMA. Global system for Mobile Communication (GSM) system overview: GSM Architecture, Mobility Management, Network signaling, mobile management, voice signal processing and coding. Spread Spectrum Systems- Cellular code Division Access Systems-Principle, Power Control, effects of multipath propagation on code division multiple access.
UNIT - III 2.5G Mobile Data Networks: Introduction to Mobile Data Networks, General Packet Radio Services (GPRS): GPRS architecture, GPRS Network nodes, EDGE, Wireless LANs, (IEEE 802.11), Mobile IP.
Third Generation (3G) Mobile Services: Introduction to International Mobile Telecommunications 2000 (IMT 2000) vision, Wideband Code Division Multiple Access (W-CDMA), and CDMA 2000, Quality of services in 3G, Introduction to 4G.
UNIT – IV
Wireless Local Loop (WLL): Introduction to WLL architecture, WLL technologies. Wireless personal area networks (WPAN): Blue tooth, IEEE 802.15, architecture, protocol stack. Wi-Max, introduction to Mobile Adhoc Networks.
Global Mobile Satellite Systems, Case studies of IRIDIUM and GLOBALSTAR systems.
This document provides an overview of GSM and MTNL. It discusses that MTNL was established in 1986 to improve telecom services in India. It then describes GSM as a mobile system using multiple radio cells, and discusses related technologies like GPRS and EDGE. The document outlines the key components of GSM including the SIM card, services provided, frequencies used, and the switching, radio, and operation subsystems. It also briefly discusses value-added services, network areas in GSM, and MTNL's joint ventures.
WAP (Wireless Application Protocol) is a standard for accessing information on mobile devices like phones. It uses WML (Wireless Markup Language) instead of HTML. WAP has a layered architecture including application, session, security, transaction, and transport layers. It allows access to the internet from mobile devices in a standardized way and is supported by most phone manufacturers and wireless networks.
Global System for Mobile (GSM) is a second generation cellular standard developed for voice services and data delivery using digital modulation. It has a network subsystem including components like the MSC, HLR, VLR, and AuC that handle call processing and subscriber information. The radio subsystem consists of BSCs controlling multiple BTSs to manage radio network access. GSM provides international roaming, high quality voice calls, and supports data services like SMS and fax in addition to voice.
The document summarizes the evolution of wireless networks from 1G to 4G. 1G networks used analog signals and standards like NMT, AMPS, and TACS. 2G introduced digital cellular and standards like GSM, CDMA, and IS-136. 2.5G provided upgrades like GPRS, EDGE, and CDMA2000 1x to support higher data rates. 3G networks supported broadband data and included W-CDMA and CDMA2000. 4G aims to provide fully integrated IP services with speeds over 100 Mbps.
sensors are what we experience the most in our life. they are even working in our body in different aspects. they may be as eyes, ears, skin, tongue etc. when we combine them they make a network. it may be a human sensor network. but i have shared something interesting about wireless sensor networks.
GPRS is a packet-based mobile data service that allows intermittent and bursty data transmissions over existing GSM networks. It uses packet switching to allocate resources only when needed, reducing connection times. GPRS supports flexible channel allocation and sharing of available resources between users. Common applications include standard IP-based services as well as GPRS-specific point-to-point and point-to-multipoint applications. Operators can generate revenue through new subscribers, services, applications, and increased data traffic under GPRS.
The document discusses the results of a study on the impact of climate change on global wheat production. Researchers found that rising temperatures will significantly reduce wheat yields across different regions of the world by the end of the century. Under a high emissions scenario, the study projects a global average decrease in wheat production of 6% by 2050, and a 17% decrease by 2100, threatening global food security.
This document compares hubs, switches, and routers. Hubs are the simplest devices that broadcast all incoming data to all ports. Switches are more intelligent and learn which devices are connected to each port to selectively broadcast data. Routers are the most advanced devices that can be programmed to understand and manipulate data, performing functions like network address translation to route packets between local networks and the internet.
The document discusses computer networks and their uses. Computer networks allow computers to exchange information and resources over various connection types. They are used in businesses to share files, printers, and databases between employees in different locations. Networks also enable communication functions like email and videoconferencing. Additionally, networks facilitate online shopping and transactions between businesses and consumers. While networks provide many benefits, they also introduce new social and security issues around topics like privacy, censorship, and cybercrime.
This document discusses advanced wireless communication technologies and their evolution over time to meet increasing data rate demands. It covers:
1) How wireless spectrum has become crowded as usage has increased, challenging engineers to develop technologies to achieve higher data rates within limited spectrum.
2) The evolution of mobile communication standards from 1G analog to 2G digital systems like GSM, and then 3G technologies like UMTS that supported data rates up to 384kbps.
3) Emerging 4G technologies aimed to support rates over 20Mbps using techniques like MIMO, adaptive modulation, and OFDM to more efficiently use available spectrum.
Mobile communication has evolved significantly since the first prediction in 1959 and demonstration in 1973. It allows users to stay connected anytime and anywhere through voice calls, SMS, and apps. The top manufacturers are Samsung, Apple, and others. While mobile technology provides many benefits, it also has environmental and human impacts that require consideration, such as the use of conflict minerals that fund violence. Future developments like 5G will further change mobile communication.
All the contents regarding SNMP basics and SNMP traps are mentioned in this presentation. Some of the additional things are using the latest version of SNMP v3. I have considered the extra details and added them in to this presentation to clear the confusions regarding SNMP traps and SNMP basics.
The working is also described in this presentation that how the SNMP works
This document discusses communication and its key aspects. It defines communication as the transfer of information from one person to another through transmitting ideas, thoughts, and values. The communication process involves a sender encoding a message and transmitting it through a channel to a receiver who decodes the message. There are different types of communication models, including the transactional process model which shows the back-and-forth interaction between a sender and receiver. Effective communication can be impacted by barriers related to the sender, receiver, or the situation.
The document provides guidance for students on the CBSE curriculum for Class XII Informatics Practices. It outlines the syllabus split up over the academic year, including topics covered in each month. The syllabus is divided into three units - Computer Networking and Open Source Concepts, Java Programming, and Relational Database Management Systems. The document also provides tables of contents and guidelines for theory and practical assignments to help students systematically learn the curriculum through a hands-on approach.
1. The document provides an overview of MySQL concepts including databases, tables, keys, and SQL commands.
2. It defines databases, DBMS, relational databases, RDBMS, benefits of using a DBMS, and introduces MySQL as an open source RDBMS.
3. It also covers SQL commands like SELECT, INSERT, UPDATE, DELETE and concepts like data types, constraints, indexes and functions.
The document discusses how effective communication is key to good leadership. It emphasizes that leaders must be good communicators who connect with and influence their community or team. Leaders should focus on clarity of speech, thinking of others, and talking less while saying more in order to stand out from the crowd and help others see their own potential.
Communication and leadership are closely intertwined. Effective communication involves encoding a message from the sender, transmitting it to a receiver, and having the receiver decode the message. Barriers to communication can prevent understanding and open communication where information is shared across all levels is important for an organization. Key aspects of communication include nonverbal cues, active listening, and selecting the right channel to deliver messages. The document emphasizes that communication is the most important skill for leadership success and that clear communication between leaders and employees is essential for an organization to thrive.
CBSE XII Database Concepts And MySQL PresentationGuru Ji
The document provides an introduction to database concepts and the relational model. It defines what a database is and discusses the purpose of databases, including reducing data redundancy and maintaining data integrity. It also describes different data models like relational, network, and hierarchical models. The relational model is then explained in detail, covering terminology, keys, views, and relational algebra operations like select, project, cartesian product. The document provides examples to illustrate database concepts and the relational model.
This document provides an overview of computer networks and networking concepts. It defines a network as an interconnected collection of autonomous computers. Key points include:
- Networks allow for resource sharing, reliability through redundancy, lower costs through centralized resources, and improved communication.
- Networking has evolved from early networks like ARPANET to the modern Internet, which connects networks globally using TCP/IP protocols.
- Common network topologies include bus, ring, and star configurations that determine how computers are physically connected.
- Various transmission media are used to connect networks including twisted pair cable, coaxial cable, fiber optics, wireless, and satellite links. Parameters like bandwidth and throughput are used to measure network performance.
This document provides an overview of key concepts in computer networks and communication. It defines what a network is, discusses the need for networking and sharing of resources, and outlines the evolution of early networks like ARPANET and NSFNET into the modern Internet. It also covers network topologies, transmission media, switching techniques, common network devices, and communication protocols.
This document provides an overview of computer networking concepts including network architecture, evolution of networking technologies, common network devices, transmission media, network topologies, wireless technologies, types of networks, standards organizations like IEEE, common network models, important network protocols, and types of servers. It covers fundamental topics in a comprehensive manner suitable for an introductory course on computer networks.
What is a network?
Need for networking
Components of Network
Types of Network
Evolution of Networking
Communication media
Data Communication Terminologies
Switching Techniques
Digital and Analog Transmission
Network Topology
Network Devices
Communication Protocols
Wireless/Mobile Computing
This document provides an overview of computer networking concepts including:
- Types of network topologies such as star, bus, ring, and mesh.
- Transmission media like twisted pair cable, coaxial cable, optical fiber, radio waves, and satellite links.
- Network devices, protocols, wireless computing, internetworking terms, open source software, security, and viruses.
The document discusses the history and development of the Internet. It began in 1969 as the ARPANET, a network created by the US government to connect universities and research labs. No single organization owns the Internet, which uses TCP/IP protocols and packet switching to connect networks worldwide. Local area networks (LANs) connect computers within the same building, while wide area networks (WANs) connect LANs across greater distances. The document also covers network topologies, types, layers of the OSI model, and common Internet services like email and search engines.
A computer network connects two or more computers that can exchange information. It allows users to share files, resources like printers and faxes, and communicate via email and messaging. There are different types of networks based on size - a local area network (LAN) connects computers in a small area like a room or building, a metropolitan area network (MAN) connects LANs within a city, and a wide area network (WAN) connects computers over long distances using various communication links. Computer networks use protocols to define communication rules between devices to ensure reliable data transmission.
This document discusses different types of computer networks based on geographical coverage, architecture, and topology. It describes Local Area Networks (LANs) as covering a small area like a room or building, with high speeds up to 1000 Mbps. Metropolitan Area Networks (MANs) span a larger area like a campus or city, with lower speeds of 10-100 Mbps. Wide Area Networks (WANs) have no boundaries and can span countries, with varying speeds based on location. Common network architectures are peer-to-peer and client-server, and common topologies include bus, star, ring, mesh, and hybrid combinations. It also discusses different transmission media like twisted pair, coaxial, and optical fiber cables.
This document provides information about computer networking including definitions, components, types, and concepts. It defines a computer network as two or more connected computers that allow people to share files, printers, and other resources. There are two main types of networks based on architecture: client-server networks with a dedicated server and peer-to-peer networks without hierarchy. Other key topics covered include network topologies (bus, star, ring, etc.), transmission media (guided, unguided), protocols, and modes of communication (simplex, half-duplex, full-duplex).
This document discusses networking concepts. It defines a network as an interconnected collection of autonomous computers that can exchange information. Networks allow for resource sharing, reliability, cost reduction, and communication. Examples of early networks discussed are ARPANET and NSFnet. The Internet is described as a worldwide network of computer networks connected through gateways and a backbone. TCP/IP, servers, switching techniques, transmission media, network topologies, and modems are also overviewed.
This document summarizes different types of computer networks. It discusses local area networks (LANs) that connect devices within a small geographic area like a home or office. Metropolitan area networks (MANs) interconnect LANs within a larger region like a city. Wide area networks (WANs) connect LANs across national and international locations using technologies like fiber optics, radio waves, and satellites. The document also describes wired and wireless connection methods, client-server and peer-to-peer network functionality, common network topologies like bus, star and ring, and protocols such as TCP/IP, IPX/SPX, and AppleTalk.
1. A computer network is an interconnected collection of autonomous computers and devices that communicate and share resources using physical wires, cables, or wireless connections.
2. The main goals of networks are resource sharing, reliability through file copies, lower costs by sharing one file server, and improved communication.
3. Common network applications include sharing data, peripherals, control/access, accessing remote databases, and communication facilities.
For N10-005 Exam
Network Plus study guide.
Covers the basic with point form answers and easy to remember.
Those who hold a Network+ certification may improve their chances of landing a job in the networking industry or increasing salary in their existing position. A Network+ also can be used to partially satisfy some prerequisites of more advanced IT certifications. For example, it qualifies as one of part of the elective exam requirement of the Microsoft Certified Systems Administrator (MCSA) certification.
This document provides information about computer networks and telecommunications. It discusses terminals, telecommunications software, communication processors, communication media, network topologies, protocols, network architectures, and internet protocols. Terminals include video display terminals and other end user workstations. Telecommunications software functions include access control, transmission control, network control, error control, and security. Common network topologies include star, ring, bus, and tree configurations. Popular internet protocols are TCP/IP, FTP, HTTP, Telnet, Gopher, and WAIS. The document also covers internet addressing, domains, email addresses, URLs, and web directories.
A network connects two or more computers through cables, phone lines, wireless technologies or radio waves to share resources like printers and files. There are two main types of networks - local area networks (LANs) confined to a small area, and wide area networks (WANs) connecting larger areas. Key hardware components include file servers, workstations, network interface cards, hubs, switches, routers and different types of cabling. Network software establishes communication protocols and operating systems that coordinate activities across multiple connected computers.
The simplified electron and muon model, Oscillating Spacetime: The Foundation...RitikBhardwaj56
Discover the Simplified Electron and Muon Model: A New Wave-Based Approach to Understanding Particles delves into a groundbreaking theory that presents electrons and muons as rotating soliton waves within oscillating spacetime. Geared towards students, researchers, and science buffs, this book breaks down complex ideas into simple explanations. It covers topics such as electron waves, temporal dynamics, and the implications of this model on particle physics. With clear illustrations and easy-to-follow explanations, readers will gain a new outlook on the universe's fundamental nature.
How to Fix the Import Error in the Odoo 17Celine George
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Let’s explore the intersection of technology and equity in the final session of our DEI series. Discover how AI tools, like ChatGPT, can be used to support and enhance your nonprofit's DEI initiatives. Participants will gain insights into practical AI applications and get tips for leveraging technology to advance their DEI goals.
2. WHAT’S A NETWORK?WHAT’S A NETWORK?
Tanebaum [1] defines a network as ‘an
interconnected collection of autonomous computers’.
AUTONOMOUS: Central to this definition is that
all computers are autonomous i.e. no computer
on a network can start, stop or control another.
INTERCONNECTED : Two or more computers
are interconnected if they can exchange
information.
3. NEED FOR NETWORKINGNEED FOR NETWORKING
Resource Sharing: The aim is to make all resource
available to anyone or everyone connected.
Reliability: The idea is –if one crashes other can
carry on.e.g. if one file is deleted from a system it’s
safely stored on an another on the network.
Cost Factor: PCs’ve better performance ratio than
micro computers. So better to have 1 pc/user with
data stored on 1 shared file server machine.
Communication Medium: the changes at one end
can suddenly be sent to the other & vice-versa. It
brings faster and better co-operation.
5. EVOLUTION OF NETWORKINGEVOLUTION OF NETWORKING
networking started way back in 1969 and has
evolved since .
The important stages are listed below:-
1.ARPANET
2.THE INTERNET
3.THE INTERSPACE
6. ARPANETARPANET
Advanced Research Projects Agency NETwork.
Way back in 1969 it began sponsored by US Dept. of
defense with the goal of linking computers at
universities and US defense. Soon the systems
began exchanging data & info.
It had handful of components but expanded a lot.
Another event was creation of another highly (better
than ARPANET)capable network by National science
Foundation namely-Nsfnet.
But nsfnet allowed didn’t allow any private business
so private companies built their own networks later
joined with arpanet & nsfnet to form internet.
7. THE INTERNETTHE INTERNET
The internet is a worlwide network of computer
networks.
It’s a super network. The common use is that
users can communicate with any other user on a
different network.
To accomplish these exchanges certain rules
(called protocols) must be followed. The internet
uses a set of protocols called as TCP/IP
(transmission control protocol/internet protocol) .
8. HOW DOES INTERNET WORKHOW DOES INTERNET WORK
All the computers are not directly connected to
internet. Rather they connect to a small network
which connect to the internet BACKBONE through
GATEWAYS.
Gateway:-Device connecting dissimilar networks.
Backbone:-Central interconnecting structures in
which other networks are plugged. (imagine the
trunk of any tree from which branches emerge
or a human backbone).
9. FUNCTIONINGFUNCTIONING
At the source computer, the message/file is
divided into very small parts called packets.
Packet has a serial number.
All packets are sent to the destination computer.
The destination computer receives these
packets (not surely serially). If a packet is
garbled or lost,it is demanded again.
The message is arranged serially to get back the
message/file.
10. INTERNET FUNCTIONINGINTERNET FUNCTIONING
The reason that internet works at all is that every
linked computer uses the same set of rules for
communication. DON,T YOU KNOW THAT A
SET OF RULES IS CALLED PROTOCOL.
TCP/IP is responsible for division and
reassembling of packets.
Ip is responsible for guiding the packets to the
proper destination.
The future of the internet is interspace.
11. THE INTERSPACETHE INTERSPACE
Interspace is a client/server software program
that allows multiple users to communicate online
with real-time audio, video and text-chat in a
dynamic 3D environments.
As the internet is a protocol eenvironment for
interconnectinf=g networks to transmit data
similarly interspace is an application envirom-
nment for interconnecting spaces to manipulate
information.
13. CIRCUIT SWITCHINGCIRCUIT SWITCHING
The complete physical connection is established
before any data can be exchanged.
Since circuits are switched it gets it’s name.
Telephone is a good example of this technique.
Earlier switching was done manually. There was
an operator who would reside in switching office
and plug a jumper connecting input & output
sockets. Now switching is done automatically.
14. PACKET SWITCHINGPACKET SWITCHING
The method is same as message switching.
The difference lies in the way of storing and
transmitting data.
Block size of data has an upper limit (that
requires transfer of chunks of data under the
limit called as packets).
The storage is in the main memory instead of on
the hard disk.
15. MESSAGE SWITCHINGMESSAGE SWITCHING
No physical copper path is established in advance
between the sender and the receiver as in circuit
switching.
Instead, the sent data is first stored in the first
switching office and then forwarded later, one hop at
a time.
Each block is received entirely, inspected for errors,
and then retransmitted. This procedure continues
until message reaches its destination. Owing to its
working principle, it is also known as store and
forward.
17. TERMSTERMS
Data channel : a medium used to carry information or
data from one point to another.
Baud : unit of measurement for the inforamtion
carryingh capacity of a communication channel. (syn:
bps-bits per second)
Other units are : Bps, kbps, Kbps, mbps (in capitals b
means byte and otherwise bit)
Bandwidth : technically, it is the difference between
the highest & the lowest frequencies of a
transmission channel or the width of allocated band
of frequencies to a channel.
People generally use it to mean the amount of
information/data travelling through a single channel at
a time. High bandwidth channels are called
broadband and low bandwidth channels narrowband
channels.
18. MOREMORE
In digital systems it is expressed in terms of bps
like if a modem works @ 57,600 bps and
another @28,800 bps ,then the first modem has
twice as bandwidth as the second one.
In analog systems it’s expressed in terms of the
highest & the lowest signal component.
Frequency is measured in terms of
cycles/second i.e. hertz. 1 kHZ = thousand
cycles/second, 1mHZ=103
1 gHZ =103
mHZ 1 tHZ
= 103
gHZ.
Data transfer rates: amount of data transferred
by a communication channel per second or a
computing or storage device.
Measured in bps, Bps, or baud.
20. TRANSMISSION MEDIATRANSMISSION MEDIA
Transmission media or communication
channels of network is nothing but the
cable/media which provides the link.
There are numerous media which can be
divided into :-
1. Guided media (includes
wires/cables)
2. Unguided media (includes any form
of wave media)
21. TWISTED PAIR CABLETWISTED PAIR CABLE
It is the most common form of wiring in data
communication applications.
General Form : two identical wires wrapped
together in a double helix.
The bleeding of a signal from one wire to
another and which can corrupt signal and
cause network errors. This form of signal
interference is called crosstalk. To reduce
crosstalk wires are twisted in pair in
twisted pair cables.
22. PROS-N-CONSPROS-N-CONS
Advantages: simple, flexible physically,
easy to install and maintain, easily
connected, very inexpensive.
Disadvantages: incapable in long range
transmission without repeaters due to high
attenuation (reduction, decrease), low
bandwidth, supports merely data rates of
1Mbps &10 Mbps (with conditioning).
23. TYPESTYPES
Types of twisted pair cable:
Unshielded twisted pair: UTP cabling is
used for variety of electronic
communications. Available in 5 categories
Type description
CAT1VGcommunication only; no data
transmission
CAT2DGT up to 4Mbps
CAT3DGT up to 10 Mbps
CAT4DGT up to 16MbpsThe UTP
cables can have maximum segment length
of 100 meters.
CAT5DGT up to 1000Mbps
24. SHIELDED TWISTED PAIRSHIELDED TWISTED PAIR
SHIELDED TWISTED PAIR(STP):
THIS TYPE OF CABLE COMES WITH
SHIELDIING OF THE INDIVIDUAL PAIRS OF
WIRES, WHICH FURTHER PROTECTS IT
FROM EXTERNAL INTERFERRENCE. ONLY
ADVANTAHGE OVER THE UTP IS GREATER
PROTECTION FROM CROSSTALK &
INTERFERRENCE. HOWEVER, IT’S HEAVIER
& COSTLIER & REQUIRES PROPER
GROUNDING AT BOTH ENDS. THE MAX
SEGMENT LENGTH IS SAME AS UTP.
25. COAXIAL CABLECOAXIAL CABLE
It consists of a solid wire core surrounded by one or more foil or wire
shields, each separated by some kind of plastic insulator. The inner core
carries the signal, and the shield provides the ground, has high electrical
properties & is suitable for high speed communication used for TV signals.
Its data transmission characteristics are considerably higher & so it’s used
as the basis for a shared cable network, with part of the bandwidth being
used for data traffic.
Advantages: greater speed, can be used as a basis for a shared cable
network.
Can be used for broadband transmission.
Bandwidth up to 400 MBPS.
Disadvantages: expensive, not compatible with twisted pair cables
Types of coaxial cables:
Thicknet: This is thicker than thinnet. Its segments can be up to 500 meters.
Thinnet: this form of coaxial cable is thinner and it can have max. length of
185 meters.
26. OPTICAL FIBREOPTICAL FIBRE
Advantages: immune to electrical & magnetic
interference.
Highly suitable for harsh industrial environment.
Secure transmission & high transmission
capacity.
Can be Used for broadband transmission.
Disadvantage: inst6allation problem. Are fragile
& may need special care to provide the
robustness required for office environment.
Connecting two fibers together or a light source
27. Types of Fiber Optic Cables
Fiber Optic cables can be either
• Single Node that supports segment length of
upto 2 Kms and bandwidth of upto 100 Mbps
• Multinode with segment length of upto
100Kms and bandwidth of 2Gbps.
28. COMPARISONCOMPARISON
Type Type Sub
type
Maximu
m
Segment
Length
Bandwidth
Supported
Installation Cost Interference
Twisted Pair
Cable
UTP
STP
100 Mtrs
100 Mtrs
200 Mbps
500 Mbps
Easy
Moderate
Cheapest
Moderate
High
Moderate
Coaxial Cable Thinnet
Thicknet
185 Mtrs
500 Mtrs
10 Mbps
10 Mbps
Easy
Hard
Cheap
Moderate
Moderate
Low
Fiber Optic
Cable
Multinode
Singlenode
2 Kms
100 Kms
100 Mbps
2 Gbps
Very
Hard
Expensive None
None
29. Micro WaveMicro Wave
Micro wave signals are used to transmit a data
without cables. The microwave signals are
similar to radio and television signals and are
used for long distance communications.
It consist of,
1. Transmitter
2. Receiver
3. Atmosphere
30. Advantages of Microwave
i) It is cheaper than digging trenches for laying
cables and maintaining repeaters and
cables. If cables get broken by variety of
causes.
ii) It offers from land acquisition
31. <HTML><HTML>
HYPER TEXT MARKUP LANGUAGE
HTML: WHAT IT IS?
Document-layout & hyperlink-specification language i.e., a
language used to design the layout of a document & specify the
hyperlinks.
Html tells the browser how to display the contents of a hypertext
document i.e., a document including text, images & other
supported media. It also tells how to make the page interactive
by using special hyperlinks.
HTML: WHAT IT IS NOT?
First of all it is not a programming language but just a descriptive
language.
It’s neither a word processing tool nor a desktop publishing
solution. It’s just a page-layout & hyperlink specification-
language.
32. XMLXML
extensible Markup Language.
XML is a markup language for documents containing
structured information.
Structured information contains both content ( words,
images etc.) & indication of what role does that content
play content in a footer is different from that of header or
content in a caption is different from a title).
∞ (HTML==XML) ??
NO. In HTML tags and semantics meaning/role of tags) is
fixed unlike in XML.
XML permits to define tags and structural relationships
between them. Since there’s no predefined tag set there
can’t be any pre-established semantics. All the semantics
of an XML is either defined by the applications that
process them or by the used stylesheets.
33. DHTMLDHTML
Dynamic HTML refers to web content that changes
each time it is viewed. e.g. same page could result
in a different page depending upon :
Geographic location of the reader
Time of day
Previous pages viewed by the reader
Profile of the reader
DHTML refers to new HTML extensions that
will enable a web page to react to user input
without sending requests to the web server.
It can be thought of as “animated HTML”.
Ex:- a piece of text can change from one
color to another upon clicking or after some
time.
34.
35.
36.
37. MODEMMODEM
A modem is a computer peripheral that allows you to
connect & communicate with other computers via
telephone lines.
MODULATORDEMODULATOR: modulation is the
process of sending data on a wave (i.e. to convert digital
signal into analog signal) & demodulation is reverse of
modulation (i.e. to convert analog signals into digital
signal).
These inter-conversion allows two computers to “speak”.
These come in 2 varieties:-
1. Internal modems (fixed within computer)
2. External modems connected externally as a peripheral)
38. MODEM@WORKMODEM@WORK
Modem converts digital signals to A/F (audio
frequency) tones the telephones line can carry &
can also do the reverse.
INSERT A DIAGRAM
Power turned on DTE & DCE run self check
39. ETHERNET CARDETHERNET CARD
In order to connect to the network each
computer must have a special network card,
called Ethernet Card.
It contains 48 bits unique address, called MAC
address.
Now a days it comes preinstalled in computers.
It is used in star & bus topology. It transfer data
@10 &100 mbps.
40. HUBHUB
A common connection point for devices on a
network.
Hubs are active (electrically amplifies the signal)
& passive (just lets the signal pass through).
Hub usually can support 8,12, or 24 RJ-45 ports.
These are often used a star or star-wired ring
topology network topology that connects network
devices in a complete circle).
Specialized software is required for port
management.
41. HUB@WORKHUB@WORK
Hubs forward the received packet from one port
to all other ports.
All users connected to a hub is in the same
segment, sharing the hub’s bandwidth. When
packets containing data reaches to all it is their
job to accept if needed or to just discard.
42. SWITCHSWITCH
A network device that filters and forwards
packets between LAN segments.
LANs that are segmented through switches are
known are called switched LANs. In the case of
ethernets they are known as switched ethernets.
43. SWITCH@WORKSWITCH@WORK
To insulate the transmission from the other
ports, the switch establishes a temporary
connection between the source and the
destination, and then terminates the connection
once the conversation is done.
Think of telephone conversation for a good
analogy.
44. REPEATERREPEATER
A network device to amplify & restore signals for
long range transmission .
It works on physical layer of OSI reference
model.
Used in long range transmission.
Repeaters are of two kinds :-
1. amplifier it amplifies all signals and noises as well)
2. Signal repeater it collects and re-transmits the
packet as if received from source)
45. BRIDGEBRIDGE
A BRIDGE is a network device that establishes an
intelligent connection between two local networks
with the same standard but with different types of
topologies.
Bridges know computers on both the sides, so they
only allow needed messages to go to the other side.
This improves performance on both sides.
As a packet arrives at the bridge, the bridge
examines the physical destination address of the
packet. Then it decides whether or not to let it pass.
It works on data link layer of OSI reference model.
46. ROUTERROUTER
It works on network layer of OSI reference model.
A router is a network device that is used to separate
different segments in a network to improve
performance and reliability. A router works like a
bridge but can handle different protocols. Ex:- it can
link ethernet to a mainframe.
It uses logical addresses unlike bridges which uses
physical address.
If the destination is unknown to a router it sends the
traffic to another router which knows the address.
47. ROUTER@WORKROUTER@WORK
Router uses a more complete packet address to
determine which router or workstation should
receive the packet next.
Routers can help ensure the most efficient path
to destination based on a network road map
called routing table.
In case a link between two routers fails the
sending router can determine an alternate route
to keep the traffic moving.
48. GATEWAYGATEWAY
A gateway is a network device that connects two dissimilar
networks. It establishes an intelligent connection between a
local network and external networks with completely
different structures.
It works on application layer of OSI reference model.
A gateway is actually a node on a network that serves as an
entrance to another network. In enterprises a computer acts
as a gateway & in homes it is the ISP which acts as a
gateway.
The gateway nodes often act as a proxy server (not actually
a server but appearing so) & a firewall a system designed
to prevent unauthorized access to or from a private
network).
The gateway is associated to both a router determines
where a packet is sent) and a switch(provides actual path).
49.
50.
51. RJ-45RJ-45
Registered Jack-45. it is an eight-wire connector,
which is commonly used to connect computers
on LAN specially Ethernets.(ethernet is a lan
architecture developed by xerox corp along with
dec and intel. It uses bus or star tropology and
supports data transfer rates of upto 10 mbps).
56. TCP/IP FTPTCP/IP FTP
Transmission control protocol/internet protocol is a layered set
of protocols.
Tcp is responsible for making sure that the commands get
through to the other end. It keeps track of all that is sent and
sends again something if it didn’t get through.
You can think of tcp as library of routines which applications
can use when they feel the need of reliable communication
with another system. Similarly tcp calls on the services of ip.
Ip ,again, can be considered as a library of certain routines
called by tcp or by any other application that may not be using
tcp.
Layering is this strategy of building several layers of protocols.
E-mail, tcp, ip can be thought of as separate layers each
calling on the services of one below.
62. VIRUSESVIRUSES
Computer Virus is a malicious program that requires a
host & is designed to make a system sick, just like a real
virus.
Three basic types:-
1. File infectors (attach themselves to a program file)
2. Boot sector viruses (installs themselves on)
3. Macro viruses (infect data files)
Characteristics of a virus are replicatibility, requirement of
host, external activation, replication ability is limited to
(virtual)system.
DAMAGES:-
1. Can destroy FAT
2. Can create bad sectors on disk or duplicate itself
3. Can format entire disk or a specific tracks
4. Can destroy specific executable files and alter data files,
causing loss of integrity
5. Can hang the system
63. TROJAN HORSESTROJAN HORSES
A trojan horse is a code hidden in a program
such as a game or a spreadsheet that looks safe
to run but has hidden side effects.
Trojan horses spread through e-mail, exchange
of disks & information exchange. Worms also
spread trojans.
It causes damages what a virus can but only
difference is its masking effect which hides its
operation.
64. WORMSWORMS
A worm is a program designed to replicate.
Characteristics of a worm:
Can replicate
No host or is self contained
Activated by creating a process (need for a multi-tasking system)
If a network worm, will replicate across communication links
How they Spread?
Worms are generally found in multitasking & network systems.
Worms, they spread autonomously, without needing any other
program, user’s action or intervention etc.
Damage ?
Disrupt or create system management problems.
Some scan for passwords and other loopholes then send it to
the attacker.
Some times they install trojans or viruses that damage our
system.
65. SPAMSPAM
Spam refers to electronic junk mail or junk
newsgroup postings. Some people define spam more
generally as any unsolicited e-mail.
Merriam-webster dictionary defines spam as unsolicited
usually commercial e-mail sent to a large number of
addresses.
AVOIDING SPAM
Creating a filter that finds and does something to e-mail
that you suspect is spam.
Another escape is not to register yourself with a true id to
sign up for things on the net. These places often share
that e-mail id with other companies that fills you with
spam in exchange of benefits.
66. VIRUS PREVENTIONVIRUS PREVENTION
It is not an easy task. Needs extra carefulness & adherence to
these guidelines:-
Never use a foreign disk without scanning for viruses.
Scan files downloaded from internet. Always.
Never boot computer from a floppy which may contain virus.
Write protect your disks.
Use licensed software.
Password protect your pc to prevent unattended
modifications.
Make regular backups.
Install & use antivirus software.
Keep antivirus software up to date.
69. HTTPHTTP
Hyper Text Transfer Protocol is an application-level but light & fast
protocol.
It’s a generic, stateless, object oriented protocol.
Another feature is typing of data representation, allowing systems to be built
independently of the data being transferred. It has been in use by WWW
since 1990.
HTTP allows an open-ended set of methods to be used to indicate
the purpose of a request.
It builds on the discipline of URI (Uniform Resource Identifier), as a location
or name, for locating resource on which method is to be applied.
Messages are passed to the HTTP in a format same as internet email or
MIME (multipurpose internet mail extensions). HTTP is also used as a
generic protocol for communication between gateways/proxies etc. to other
protocols.
It consists of two fairly distinct items: 1. set of requests from browsers to
servers 2. set of responses going the other way.
Though HTTP was designed to work with web but it’s been made more
general to accommodate future possibilities of OO applications.
HTTP has different built-in methods to allow users to open a web page, to
disconnect an existing connection, to read the header of a webpage, to
append to an existing resource or to store a webpage etc.
70. URL & DOMAIN NAMESURL & DOMAIN NAMES
HTTP uses internet address in a special format called a Uniform
Resource Locator or URL.
Typically URLs look like this:
type://address/path
Type:- type of server address (also the protocol they use):- address
of the server path:- location of file on the server.
In the address last group of characters (.com, .gov etc.) is domain
indicator.
The naming scheme by which servers are identified is known as
domain name system.
Another method of addressing (identifying server) is by assigning
distinct numbers known as IP addressing method. Such addresses
are called as IP addresses.
Lastly, a url specifies a distinct address for each resource on the
net. A character based internet address is a domain name.
73. WEB-BROWSERS & SERVERSWEB-BROWSERS & SERVERS
A web browser is a WWW client that navigates
through the World Wide Web and displays web-
pages.
A web server is a WWW server that responds to
the requests made by the web browsers.
74. WEB SITES,WEB SITES, ADDRESSESADDRESSES & PAGES& PAGES
A location on a net server is called web sites.
The unique address of each (URL) is called
address.
A web page is document or simply a page in a
web site.
75. WEB HOSTINGWEB HOSTING
Web hosting is a means of hosting web-server
application on a computer system through which
electronic content on the internet is readily available to
any web browser client.
Web Hosting Can Be Grouped Under:
1.free hosting:- site hosting for free. You too can put
up own websites for raw fun.
2. virtual or shared hosting : virtual hosting is where
one’s site is hosted on the web server of the hosting
company along with other web-sites giving 24-hour
access& can be updated through a password log-in.
3.dedicated hosting: a dedicated server is rented
usually for big websites by companies. Dedicated for
large, high traffic, or for those with special needs e.g.
e-commerce, security.
76. WEB SCRIPTINGWEB SCRIPTING
A script is a list of commands embedded in a web-page.
Scripts are interpreted and executed by a certain program or
script-engine.
Most common scripting languages are VBScript, ASP(Active
Server Pages), JavaScript, PHP(Hypertext Preprocessor),
PERL, JSP etc.
Types of scripts:
Client-side script : It enables interaction within the web-
page, is downloaded and executed by the browser (is
browser-dependent i.e. browser must be enabled to run
the script).Applications : To get data from user’s screen or
browser, online games, customized web-pages.
Server-side script: It supports execution at server end.
Results are sent to the client, is browser independent of
browsers. APPLICATIONS : password protection, dynamic
addition of content to web-pages.
77. WEB SCRIPTING Contd…WEB SCRIPTING Contd…
4. co-location hosting: the company actually owns the
server & is responsible for all server administration
and the web hosting company provides physical
requirements of rack, high speed connection, a
regular power supply, and a limited amount of
technical support such as data back up or hardware
upgrades.
81. OPEN SOURCE SOFTWAREOPEN SOURCE SOFTWARE
Open Source Software commonly means software whose licenses
do not impose much conditions. Users are free to use, modify &
distribute software hassle-free but not certainly free of charge.
It has been officially defined by the open source definition at
http://www.opensource.org/docs/definition_plain.html. It states that :-
Open source doesn’t just mean access to source code. The
distribution terms of open-source software must comply with the
following criteria :-
1. Free Redistribution
2. Source Code
3. Derived Works
4. Integrity of The Author’s Source Code
5. No Discrimination Against Persons Or Groups
6. No Discrimination Against Fields Of Endeavor
7. Distribution Of License
8. License Must Not Be Specific To A Product
9. The License Must Not Restrict Other Software
10.License Must Be Technology Neutral
82. FREEWAREFREEWARE
The term freeware has no clear definition, but
generally refers to free of cost & redistributable
software, but no modification & no source code.
It is distributed in binary form.
Freeware is often used in marketing situations in
order to sell products and gain market
advantages.
One example is Microsoft Internet Explorer.
83. SHAREWARESHAREWARE
Shareware is a software, which is made
available with the right to redistribute copies, but
it is stipulated that if one intends to use the
software, often after a certain period of time,
then a license fee must be paid.
Source code & modifiability absent.
The objective is to increase no. of prospective
users.
Generally a built-in timed mechanism limits the
functionality after a certain period of time.
84. PROPRIETARY SOFTWAREPROPRIETARY SOFTWARE
Neither open nor free, its use is regulated and
further distribution and modification is either
forbidden or requires special permission by the
supplier or vendor.
Normally the source code is not given to the
user.
85. FLOSSFLOSS
FLOSS refers to Free Livre And Open Source
Software or to Free Libre And Open Source
Software.
The term is used for software that is both free
software and open software.
Here the words libre(a Spanish word) or livre(a
Portuguese word) mean freedom.
86. GNUGNU
GNU is a recursive acronym for GNU’s NOT UNIX.
This project was initiated by richard m. stallman with
an objective to create a system compatible with UNIX
but not same as UNIX.
It has not only made an OS but the project has grown
since its inception and now it creates software of
almost all kinds.
The same person founded the Free Software
Foundation.
87. FSFFSF
FSF is Free Software Foundation. It is a non
profit organization created to support free
software movement in 1985 by Richard M
Stallman.
FSF has funded many software developers to
write free software.
Now a days, it also works on legal and structural
issues for the free software community.
88. OSIOSI
OSI is Open Source Initiative founded byBruce
perens & erics raymond (in feb 1998) .
Itr specififes the criteria for open source software
& properly defines terms and specifications for
open source software.