ASSIGNMENT#4 SUBMITTED BY Jibran Shah 1411-320009 Syed Daniyal 1411-320043 M.Nouman Ashraf 1411-320027 Fahad Nisar 1411-320066 SUBMITTED TO Prof. Dr. MSH Khiyal SUBJECT Computing Essential 1) Discuss communication channels including physical connections (twisted-pair, coaxial, and fiber-optic cable) and wireless communications (radio frequency, microwave, satellite, and infrared). ANS. COMMUNICATION CHANNEL: A communication channel refers either to a physical transmission medium such as a wire, or to a logical connection over a multiplexed medium such as a radio channel in telecommunication and computer networking. A channel is used to convey an information signal, for example a digital bit stream, from one or several senders (or transmitters) to one or several receiver. A channel has a certain capacity for transmitting information, often measured by its bandwidth in Hz or its data rate in bits per second PHYSICAL CONNECTIONS: Communicating data from one location to another requires some form of pathway or medium. These pathways, called communication channels, use two types of media: cable (twisted-pair wire, cable, and fiber-optic cable) TWISTED PAIR WIRE: Twisted-pair cable is a type of cabling that is used for telephone communications and most modern Ethernet networks. A pair of wires forms a circuit that can transmit data. The pairs are twisted to provide protection against crosstalk, the noise generated by adjacent pairs. COXIAL CABLE: Coaxial cable is a type of cable that has an inner conductor surrounded by an insulating layer, surrounded by a conductive shielding.It is commonly used by cable operators, telephone companies, and internet providers around the world to convey data, video, and voice communications to customers. It has also been used extensively within homes. FIBRE OPTIC CABLE: A fibre optic cable can contain a varying number of these glass fibres, from a few up to a couple hundred. Surrounding the glass fibre core is another glass. A fibre optic cable is a network cable that contains strands of glass fibres inside an insulated casing. They're designed for long-distance, highperformance data networking, and telecommunications. Compared to wired cables, fibre optic cables provide higher bandwidth and transmit data over longer distances. There are two types of fibre optic cable: Fiber Multimode Cable Fiber Single mode Cable Fibre Multimode Cable: Multi-mode optical fibre is a type of optical fibre mostly used for communication over short distances, such as within a building or on a campus. Fiber Single mode Cable: A single-mode optical fibre is an optical fibre designed to carry only a single mode of light - the transverse mode. Modes are the possible solutions of the Helmholtz equation for waves, which is obtained by combining Maxwell's equations and the boundary conditions. WIRELESS CONNECTIONS: Wireless Communication is the fastest growing and most vibrant technological areas in the communication field. Wireless Communication is a method of transmitting information from one point to other, without using any connection like wires, cables or any physical medium. MICROWAVE: Microwave is a line-of-sight wireless communication technology that uses high frequency beams of radio waves to provide high speed wireless connections that can send and receive voice, video, and data information. SATELLITE: Satellite communication is the method of transporting information from one place to another using a communication satellite in orbit around the Earth. Telephone, radio, television, internet, and military applications use satellite communications. RADIO FREQUENCY: A radio frequency signal refers to a wireless electromagnetic signal used as a form of communication, if one is discussing wireless electronics. Frequency refers to the rate of oscillation (of the radio waves.) RF propagation occurs at the speed of light and does not need a medium like air in order to travel. INFRARED: Infrared, communication is a common, inexpensive, and easy to use wireless communication technology. ... For example, when you hit a button on your TV remote, an IR LED repeatedly turns on and off, 38,000 time a second, to transmit information (like volume or channel control) to an IR photo sensor on your TV. 2) Discuss connection devices including modems (telephone, DSL, cable, and wireless modems) and connection services (DSL, ADSL, cable, and satellite connection services). ANS. CONNECTION DEVICES: Connecting devices are bridges between the different parts of a document that tie all of the pieces together into one coherent package. Connecting devices show the reader how various sections of information are related, and they help keep the reader o n track with the flow of information. Documents which do not include connecting devices are disjointed, choppy and difficult to read. Connecting devices are analogous to the traffic signals people rely on when driving. Imagine a major metropolitan are a, such as Seattle, without bridges, traffic signs or traffic lights to guide drivers through traffic. Chaos and confusion would abound! The same is true of a document which lacks connecting devices: the reader will have a difficult time following the writer's train of thought and the document will not flow smoothly. MODEM: Modem Short for modulator-demodulator In a communication modem converts the digital data into analog so that it transmits over the phone line because the phone line transmits analog data. In the same way on the other hand when data is received modem again convert this analog data into a digital single so that computer store and process on this information. TELEPHONE: It is a network device that modulates digital information or bits into analog signals for transmission at the sending end, and demodulates the analog signals to bits at the receiving end. Telephone modems enables data communication between two computers over voice grade telephone lines. DSL: DSL stands for Digital Subscriber Line. Users get a high speed bandwidth connection from a phone wall jack on an existing telephone network. DSL works within the frequencies that the telephone doesn't so you can use the Internet while making phone calls. CABLE: An Ethernet crossover cable is a type of twisted pair Ethernet cable used to connect computing devices together directly that would normally be connected via a network switch, Ethernet hub or router, such as directly connecting two personal computers via their network adapters. WIRELESS MODEM: A wireless modem is a modem that bypasses the telephone system and connects directly to a wireless network, through which it can directly access the Internet connectivity provided by an Internet service provider (ISP). CONNECTION SERVICES: DSL: DSL stands for Digital Subscriber Line. Users get a high speed bandwidth connection from a phone wall jack on an existing telephone network. DSL works within the frequencies that the telephone doesn't so you can use the Internet while making phone calls. ADSL: Asymmetric Digital Subscriber Line (ADSL) is a technology that provides high transmission speeds for video and voice to homes over an ordinary copper telephone wire. It will be most cost-effective in areas with a low market penetration of cable TV. CABLE: An Ethernet crossover cable is a type of twisted pair Ethernet cable used to connect computing devices together directly that would normally be connected via a network switch, Ethernet hub or router, such as directly connecting two personal computers via their network adapters. SATELLITE CONNECTION SERVICE: A satellite Internet connection is an arrangement in which the upstream (outgoing) and the downstream (incoming) data are sent from, and arrive at, a computer through a satellite. ... In a two-way satellite Internet connection, the upstream data is usually sent at a slower speed than the downstream data arrives. 3) Discuss data transmission including bandwidths (voiceband, medium band, broadband, and baseband) as well as protocols (IP addresses, domain name servers, and packetization). ANS. DATA TRANSMISSION: A satellite Internet connection is an arrangement in which the upstream (outgoing) and the downstream (incoming) data are sent from, and arrive at, a computer through a satellite. ... In a two-way satellite Internet connection, the upstream data is usually sent at a slower speed than the downstream data arrives. BANDWIDTH: A satellite Internet connection is an arrangement in which the upstream (outgoing) and the downstream (incoming) data are sent from, and arrive at, a computer through a satellite. ... In a two-way satellite Internet connection, the upstream data is usually sent at a slower speed than the downstream data arrives. VOICEBAND: This refers to the transmission of (voice) information over a relatively narrow band of frequencies, called the voice spectrum (about 0–3,500 Hz), for which telephone networks have been designed. Your dialup 56-Kbps modem is an example of a voiceband modem. MEDIUMBAND: Coaxial cable is a widely used wire medium, which offers a bandwidth of approximately 750 MHz. ... Communication through free space using radio waves takes place over a very wide range of frequencies: from a few hundreds of kHz to a few GHz. BROADBAND: Broadband is a term refers to the width of a band. It is simply a high-speed, always-on internet connection in terms of transmission capacity. Bandwidth is the maximum data transfer rate from one point to another at a given time period over a network BASEBAND: A baseband bandwidth is equal to the highest frequency of a signal or system, or an upper bound on such frequencies, for example the upper cutoff frequency of a low-pass filter. By contrast, passband bandwidth is the difference between a highest frequency and a nonzero lowest frequency PROTOCOLS: IP ADRESSES: An Internet Protocol address (IP address) is a numerical label assigned to each device connected to a computer network that uses the Internet Protocol for communication. An IP address serves two main functions: host or network interface identification and location addressing. DOMAIN NAME SERVER: DNS uses the User Datagram Protocol (UDP) on port 53 to serve DNS queries. UDP is preferred because it is fast and has low overhead. A DNS query is a single UDP request from the DNS client followed by a single UDP reply from the server . PACKETIZATION: The second driver behind the rise of platforms is packetization. Packetization is the ability to digitize “something "an activity, a process, a product, or a service that was previously not digitized. Anything that can be digitized can be broken into Internet data “packets” and transported quite literally at the speed of light and at near zero cost across large distances. 4) Discuss networks by identifying and defining specialized terms that describe computer networks. ANS. Identifying the Types of Networks: One of the areas of networking that the A+ Certification Exams cover is networking theory/networking hardware. Being able to identify the types of networks is important. A network is a group of connected systems for sharing data or devices. The two major types of networks are peer-to-peer and server-based (client-server). Peer-to-peer networks In a peer-to-peer (P2P) network, all systems connected to the network can act as clients or servers. A client is a system that makes a request for a resource or service on the network; a server is the system providing the resource or service. In this type of networking environment, all systems are considered equal because they can all play the same roles on the network — either as client or server or as both client and server. The recommended number of systems in a P2P network usually involves ten or fewer systems because of the lack of centralized administration. As a network administrator working in a P2P environment, you will constantly run from machine to machine to perform administrative tasks. Typically, a P2P network involves each system running a desktop operating system, such as Windows 8.1 to provide network functionality. Server-based (client-server) networks: Server-based networking, also known as client-server networking, is the networking model that most companies usually choose for ten or more workstations on a network. Unlike a P2P network, server-based networking uses a central machine (the server) that delivers network services to the workstations. Once again, these network services could be services such as file and print sharing, user account authentication, or web services. Server roles When creating a network, you can install servers that provide a number of different types of functionality to the network. Following is a list of the common types of server roles that exist on networks today: Web server: A web server delivers web pages to clients using the HTTP or HTTPS protocol. Web servers host public websites or intranet sites used inside a company. File server: A file server stores data documents such as Microsoft Word, Excel, and PowerPoint files. The file server typically offers permission capabilities so that you can control who can access what files. Print server: A print server is used to share printers with network clients and queue print jobs while they are waiting to be printed. DHCP server: A DHCP server is responsible for handing out IP addresses to clients on the network so that you do not need to run around to each client and manually configure an IP address. DNS server: A DNS server is responsible for translating fully qualified domain names such as www.gleneclarke.com to its IP address. Proxy server: A proxy server is responsible for sending requests to the Internet on behalf of the user. A proxy server adds a layer of security, in that the user is not sending the request to the Internet directly. A proxy server typically has NAT features and policy features to control which websites users are allowed to access. Mail server: A mail server is responsible for sending and receiving email for users within the company. Authentication server: An authentication server stores all of the usernames and passwords for the network in a database, and is responsible for verifying the username and password of the users when they log onto the network. Before accessing files on a file server or reading email, users typically must authenticate to the authentication server first. Computer network, two or more computers that are connected with one another for the purpose of communicating data electronically. Besides physically connecting computer and communication devices, a network system serves the important function of establishing a cohesive architecture that allows a variety of equipment types to transfer information in a near-seamless fashion. Two popular architectures are ISO Open Systems Interconnection (OSI) and IBM’s Systems Network Architecture (SNA). Two basic network types are local-area networks (LANs) and widearea networks (WANs). LANs connect computers and peripheral devices in a limited physical area, such as a business office, laboratory, or college campus, by means of links (wires, Ethernet cables, fibre optics, Wi-Fi) that transmit data rapidly. A typical LAN consists of two or more personal computers, printers, and highcapacity disk-storage devices called file servers, which enable each computer on the network to access a common set of files. LAN operating system software, which interprets input and instructs networked devices, allows users to communicate with each other; share the printers and storage equipment; and simultaneously access centrally located processors, data, or programs (instruction sets). LAN users may also access other LANs or tap into WANs. LANs with similar architectures are linked by “bridges,” which act as transfer points. LANs with different architectures are linked by “gateways,” which convert data as it passes between systems. WANs connect computers and smaller networks to larger networks over greater geographic areas, including different continents. They may link the computers by means of cables, optical fibres, or satellites, but their users commonly access the networks via a modem (a device that allows computers to communicate over telephone lines). The largest WAN is the Internet, a collection of networks and gateways linking billions of computer users on every continent. 5) Discuss network types including local area, home, wireless, personal, metropolitan, and wide area networks. ANS. NETWORKS: There are various types of computer networks available. We can categorize them according to their size as well as their purpose. The size of a network should be expressed by the geographic area and number of computers, which are a part of their networks. It includes devices housed in a single room to millions of devices. PAN (Personal Area Network)? PAN is a computer network formed around a person. It generally consists of a computer, mobile, or personal digital assistant. PAN can be used for establishing communication among these personal devices for connecting to a digital network and the internet. Characteristics of PAN It is mostly personal devices network equipped within a limited area. Allows you to handle the interconnection of IT devices at the surrounding of a single user. PAN includes mobile devices, tablet, and laptop. It can be wirelessly connected to the internet called WPAN. Appliances use for PAN: cordless mice, keyboards, and Bluetooth systems. Advantages of PAN Here, are important pros/benefits of using PAN network: PAN networks are relatively secure and safe It offers only short-range solution up to ten meters Strictly restricted to a small area Disadvantages of PAN Here are important cons/ drawback of using PAN network: It may establish a bad connection to other networks at the same radio bands. Distance limits. LAN: A Local Area Network (LAN) is a group of computer and peripheral devices which are connected in a limited area such as school, laboratory, home, and office building. It is a widely useful network for sharing resources like files, printers, games, and other application. The simplest type of LAN network is to connect computers and a printer in someone's home or office. In general, LAN will be used as one type of transmission medium. It is a network which consists of less than 5000 interconnected devices across several buildings. Characteristics of LAN Here are important characteristics of a LAN network: It is a private network, so an outside regulatory body never controls it. LAN operates at a relatively higher speed compared to other WAN systems. There are various kinds of media access control methods like token ring and ethernet. Advantages of LAN Here are pros/benefits of using LAN: Computer resources like hard-disks, DVD-ROM, and printers can share local area networks. This significantly reduces the cost of hardware purchases. You can use the same software over the network instead of purchasing the licensed software for each client in the network. Data of all network users can be stored on a single hard disk of the server computer. You can easily transfer data and messages over networked computers. It will be easy to manage data at only one place, which makes data more secure. Local Area Network offers the facility to share a single internet connection among all the LAN users. Disadvantages of LAN Here are the important cons/ drawbacks of LAN: LAN will indeed save cost because of shared computer resources, but the initial cost of installing Local Area Networks is quite high. The LAN admin can check personal data files of every LAN user, so it does not offer good privacy. Unauthorized users can access critical data of an organization in case LAN admin is not able to secure centralized data repository. Local Area Network requires a constant LAN administration as there are issues related to software setup and hardware failures WAN: WAN (Wide Area Network) is another important computer network that which is spread across a large geographical area. WAN network system could be a connection of a LAN which connects with other LAN's using telephone lines and radio waves. It is mostly limited to an enterprise or an organization. Characteristics of LAN: The software files will be shared among all the users; therefore, all can access to the latest files. Any organization can form its global integrated network using WAN. Advantages of WAN Here are the benefits/ pros of using WAN: WAN helps you to cover a larger geographical area. Therefore business offices situated at longer distances can easily communicate. Contains devices like mobile phones, laptop, tablet, computers, gaming consoles, etc. WLAN connections work using radio transmitters and receivers built into client devices. Disadvantage of WAN Here are drawbacks/cons of using WAN: The initial setup cost of investment is very high. It is difficult to maintain the WAN network. You need skilled technicians and network administrators. There are more errors and issues because of the wide coverage and the use of different technologies. It requires more time to resolve issues because of the involvement of multiple wired and wireless technologies. Offers lower security compared to other types of networks. Home Area Network (HAN): A Home Area Network is always built using two or more interconnected computers to form a local area network (LAN) within the home. For example, in the United States, about 15 million homes have more than one computer. 6) Define and discuss online identity and the major privacy laws. ANS. ONLINE IDENTITY: Online identity or internet persona, is a social identity that an Internet user establishes in online communities and websites. It can also be considered as an actively constructed presentation of oneself. Some websites also use the user's IP address or tracking cookies to identify users. PRIVACY LAW: Privacy law refers to the laws that deal with the regulation, storing, and using of personally identifiable information, personal healthcare information, and financial information of individuals, which can be collected by governments, public or private organisations, or other individuals. 7) Define security and discuss computer criminals including employees, hackers, crackers, carders, and organized crime. ANS. SECURITY: A security is a financial instrument, typically any financial asset that can be traded. The nature of what can and can't be called a security generally depends on the jurisdiction in which the assets are being traded. Equity securities which includes stocks and debt securities which includes bonds and banknotes. COMPUTER CRIME: Alternatively referred to as cyber crime, e-crime, electronic crime, or hi-tech crime. Computer crime is an act performed by a knowledgeable computer user, sometimes referred to as a hacker that illegally browses or steals a company's or individual's private information. In some cases, this person or group of individuals may be malicious and destroy or otherwise corrupt the computer or data files. Employees: Organizations today are more susceptible to computer crime and employee fraud than ever before. This paper presents some statistics about the growth on fraud, factors which cause fraud in the workplace, how businesses can protect their assets, and common computer‐ based frauds, techniques, and controls. Managers of all types of organizations need to be knowledgeable about their internal control system, and make sure it has sufficient checks and balances to ward against employees committing fraudulent acts. No organization is immune today from both external and internal threats to the safety and security of their data and information. Therefore, it is imperative that managers understand the problems that fraud can cause and how they can protect the organization. HACKER: Hacking is the activity of identifying weaknesses in a computer system or a network to exploit the security to gain access to personal data or business data.System hacking means using computers to commit fraudulent acts such as fraud, privacy invasion, stealing corporate/personal data, etc. CRACKER: A cracker is someone who breaks into someone else's computer system, often on a network; bypasses passwords or licenses in computer programs; or in other ways intentionally breaches computer security. Some breaking-andentering has been done ostensibly to point out weaknesses in a site's security system. CARDERS: Carding is a term describing the trafficking of credit card, bank account and other personal .Many forums also provide related computer crime services such as phishing kits, malware and spam lists. ORGANIZED CRIME: Criminal groups that engage in cyber organized crime also provide services that facilitate crimes and cybercrimes (crime as a service), such as data and identity documents (e.g., financial and health data, passports, voter registration identifications); malware (i.e., made to order or known malware - e.g., Zeus 8) Define computer crime and the impact of malicious programs, including viruses, worms, and Trojan horses, and zombies as well as cyber-bullying, denial of service, Internet scams, social networking risks, rogue Wi-Fi hotspots, theft, data manipulation, and other hazards. ANS. COMPUTER CRIME: Computer crime is an act performed by a knowledgeable computer user, sometimes referred to as a hacker that illegally browses or steals a company's or individual's private information. In some cases, this person or group of individuals may be malicious and destroy or otherwise corrupt the computer or data files. The impact of malicious programs, including viruses, worms, and Trojan horses: Worms Trojan horseZombiesDenial of Service(DoS) attack Creation of malicious programs – called malware (key term)which is short for malicious software Crackers (key term) create and distribute malicious programs Viruses (key term)–migrate through networks and operating systems and most attach themselves to different programs and databases; can alter and/or delete files; can damage system components; Computer Fraud and Abuse Act (key term) makes spreading a virus a federal offense Worms (key term) – a special type of virus Doesn't attach to a program Fills the computer with self-replicating information or can be a carrier of a more traditional virus Trojan horse (key term) – programs that are disguised as something else; like worms they are carriers of viruses; The most common type of Trojan horses appear as free computer games. Zombies (key term) – computers infected by a virus, worm, or Trojan horse that allows them to be remotely controlled for malicious purposes collection of Zombie computers is knows as a botnet (key term), or robot network (key term). Malicious activities include password cracking or sending junk. Denial of service attacks (key term) – attempts to slow down or stop a computer system or network by flooding a computer or network with requests for information and data. The targets of these attacks are usually ISPs. Computer Crime (Cont.) Rogue Wi-Fi hotspots Data manipulation Computer Fraud and Abuse Act Identity Theft Cyber-bullyingRogue Wi-Fi Hotspots (key term) imitate free Wi-Fi networks and capture any and all information sent by the users to legitimate sites including usernames and passwords. Data manipulation – finding entry into someone’s computer network and leaving a prankster’s message Computer Fraud and Abuse Act – law states that it’s a crime for an unauthorized person to view, copy or damage data using any computer across state lines Identity Theft – illegal assumption of someone’s identity for purpose of economic gain Cyber-bullying (key term) the use of the Internet, cell phones, or other devices to send or post content intended to hurt or embarrass another person. Sending repeated unwanted sganging up on victims in electronic forums posting false statements designed to injure the reputation of another maliciously disclosing personal data about a person that could lead to harm to that person sending any type of communication that is threatening or harassing Computer Crime/ Internet scams: A fraudulent or deceptive act or operation to trick someone into providing personal information or spending money for little or no return 9) Discuss ways to protect computer security including restricting access, encrypting data, anticipating disasters, and preventing data loss. ANS. WAYS TO PROTECT COMPUTER SECURITY: Principle measures to ensure computer security Restricting access Encrypting data Anticipating disasters Physical security Data security Disaster recovery plan Preventing data loss Security involves protecting information, hardware, and software from unauthorized use, damage from intrusions, sabotage, and natural disasters Encryption: coding messages to prevent people from reading your messages Restricting Access Biometric scanning Passwords Security Suites: Fingerprint scanners Iris (eye) scanners PasswordsDictionary Suites Firewalls Computers should be protected from unauthorized access Biometric scanning (key term) fingerprint or eye scanners Passwords (key term)Change passwords when people leave a company Dictionary attack (key term) – uses software to try thousands of common words sequentially in an attempt to gain unauthorized access to a user’s account. Words, names, and simple numeric patterns make poor passwords. Security Suites (key term) provide a collection of utility programs designed to protect your privacy and security Firewalls (key term) – a security buffer between a corporation’s private network and all external networks Fingerprint scanner Data Encryption: Coding information to make it unreadable, except to those who have the encryption keyencryption File encryption Web site encryption Virtual private networks (VPNs)Wireless network encryption WEP, WPA, and WPA2Encryption (key term) process of coding information to make it unreadable except to those who hold an encryption key (key term) or key (key term) used for decryptionencryption File encryption Website encryption Https(key term) is the most common protocol for website encryption and HTTP (key term) is the most widely used Internet protocol VPNs (key term) encrypt connections between company networks and their remote users Wireless network encryptionWPA2 – Wi-Fi Protected Access (key term) Anticipating Disasters: Physical Security Data Security Disaster Recovery Plan Preventing Data Loss Frequent backups Redundant data storage Anticipating disasters Physical security (key term)– protecting hardware Data security (key term)– protecting software and data from unauthorized tampering or damage Disaster recovery plan (key term)– describing ways to continue operating until normal computer operations can be restored; can create special emergency facilities called hot sites which are fully equipped backup computer centres or cold sites if hardware must be installed to be utilized Preventing data loss Use physical backups – off-site storage using tapes or disks in case of loss of equipment. 10) Define ethics and describe copyright law and plagiarism. ANS. ETHICS: Computer ethics is defined as the analysis of the nature and social impact of computer technology and the corresponding formulation and justification of policies for the ethical use of such technology. The typical problem with computer ethics is the policy vacuum that arises from the new capabilities of the technology. PLAGIARISM: Plagiarism is using someone else's work or ideas without giving proper credit. In other words, because you are not giving attribution to the owner of the original work or idea -- you are presenting the idea or thought as your own. Plagiarism is a violation of academic norms but not illegal; copyright violation is illegal but quite common in academia. Plagiarism is an offense against the author; copyright violation is an offense against the copyright holder. In traditional academic publishing, they are usually not the same person, because copyright transfer agreements (CTAs) are so common. Plagiarism applies when ideas are copied; copyright violation occurs only when a specific fixed expression (e.g., sequence of words, use of an image) is copied. Avoiding plagiarism is about properly apportioning intellectual credit; copyright is about maintaining revenue streams. COPYRIGHT: Copyright is a legal term describing ownership of control of the rights to the use and distribution of certain works of creative expression, including books, video, movies, music and computer programs. Historically, copyright law has been enacted to balance the desire of cultures to use and reuse creative works (thus creating "derivative work") against the desire of the creators of art, literature, music and the like to monetize their work by controlling who can make and sell copies of the work.