Module 5: Telecommunications and Networks - PDF

Module 5: TELECOMMUNICATIONS AND NETWORKS Fundamentals of Information Systems Learning objectives Apply Metcalfe’s law in understanding the value of a network Identify major developments and trends in the industries, technologies, and business applications of telecommunications and Inter...

Module 5: TELECOMMUNICATIONS AND NETWORKS Fundamentals of Information Systems Learning objectives Apply Metcalfe’s law in understanding the value of a network Identify major developments and trends in the industries, technologies, and business applications of telecommunications and Internet technologies Understand Internet, intranet, and extranet applications Identify the basic components, functions, and types of telecommunications networks used in business Explain the concept of client/server networking Understand the two forms of peer-to-peer networking Explain the difference between digital and analog signals Network Concepts What is a NETWORK? A network is an interconnected or interrelated chain, group, or system Example: Internet, airline network, social network * The number of possible connections on a network is N(N–1) or N2 –N N = number of nodes (points of connection) Example: 10 computers on a network = 10(10–1) = 10x9 = 90 possible connections 3 Metcalfe’s Law – USABILITY OF NETWORK SYSTEM Robert Metcalfe founded 3Com Corp. and designed the Ethernet protocol for computer networks Metcalfe’s Law: The usefulness, or utility, of a network equals the square of the number of users. 🡪 The more users on a network, the more useful it becomes. Example: The Internet is growing exponentially. We can expect more value, for less cost, virtually every time we log on. 4 Telecommunication Telecommunication is the exchange of information in any form (voice, data, text, images, audio, video) over networks. Early telecom networks – slower; without use of computer Why do we need to setup telecommunication? Share data – between computers: Email, file-sharing, backup files Share peripheral devices – printers and storage devices 5 Trends in telecommunications INDUSTRY Trend Started from government regulated monopolies to a market with competitive suppliers of telecoms services. Telecommunications-Based Services The spectrum of telecommunications-based services available today. 7 TECHNOLOGY TREND Internet networking technologies are being used as technology platform Examples: Web browser suites HTML Web page editors Network management software Firewalls Being applied in Internet, intranet, and extranet applications Reinforces previous move toward client/server networks based on open-systems architecture 8 Technology trend - Open Systems Open systems are information systems that use common standards for hardware, software, applications, and networks Internet networking technologies are a common standard for open systems Open systems provide: Greater Connectivity – ability to communicate NCs with one another easily Network Interoperability – enable the many different activities of end users to be accomplished using the different varieties of computer systems, software packages, and databases provided by a variety of interconnected networks. Middleware may be needed to help diverse systems work together 9 TECHNOLOGY Trend - Middleware Middleware A general term for any programming that mediates between two separate programs Commonly known as the “plumbing” of an information system Because it routes data and information between back-end data sources and end user applications An essential component of any IT infrastructure 10 TECHNOLOGY Trend - Digital Network Technologies Telecommunications are being revolutionized by switch from analog to digital Analog: voice-oriented transmission Digital: discrete pulse transmission Benefits Higher transmission speeds Moves larger amounts of information Greater economy and much lower error rates Transmits multiple types of communications (data, voice, video) on the same circuits 11 Technology trend - Wireless Technologies Use of Fiber-optic transmission: Uses pulses of laser-generated light Reduced size and installation effort Vastly greater communication capacity Faster transmission speeds Freedom from electrical interference Satellite Transmission Can move massive quantities of data, audio, and video over global networks Especially useful in isolated areas 12 Business Application Trends Telecommunications networks now play a vital and pervasive role in Web-enabled… E-business processes Electronic commerce Enterprise collaboration Other applications that support operations, management, and strategic objectives 13 BUSINESS Trend - Internet2 Next generation of the Internet High-performance network Uses a different infrastructure than the current Internet Will not replace the current Internet In use at over 200 universities, scientific institutions, communications corporations May never become totally open Purpose of sharing, collaborating and trying new high-speed communication ideas. Users are connected via Abilene, a backbone that supports throughput of 10 Gbps Infinite bandwidth 14 Business Value of Telecommunications Networks 15 The Internet Revolution The Internet has become a global information superhighway Internet is a network made up of millions of smaller, private networks operating independent of, or in harmony with, each other 10 servers in 1991 to over 46 million in 2004. 2007 = 1 billion+ users Sustained growth in excess of 1 million servers per month No central computer system. Instead they have root servers No governing body Based on common standards 16 Internet Service Providers ISP A company that specializes in providing easy access to the Internet For a monthly fee, provides software, user name, password, and Internet access ISPs themselves are connected to one another through network access points One ISP can easily connect to another to obtain addresses of websites or user nodes 17 Internet Applications Most popular Internet applications and uses E-mail Instant messaging Browsing the Web Newsgroups Chat rooms Publish opinions, subject matter, creative work Buy and sell Downloading (data, software, reports, pictures, music, videos) 18 Popular use of internet Business Use of the Internet 20 Business Value of the Internet The Internet provides a synthesis of computing and communication capabilities that adds value to every part of the business cycle. 21 Types of internet access Intranets An intranet is a network inside an organization that uses Internet technologies (such as Web browsers and servers, TCP/IP network protocols, HTML hypermedia document publishing and databases, and so on) to provide an Internet-like environment within the enterprise for information sharing, communications, collaboration, and the support of business processes. Intranets are protected by… Passwords Encryption Firewalls Customers, suppliers, and other business partners can access an intranet via extranet links 23 The Role of Intranets Many companies have sophisticated and widespread intranets, offering… Detailed data retrieval Collaboration Personalized customer profiles Links to the Internet Intranets use Internet technologies Web browsers and servers TCP/IP network protocols HTML publishing and databases 24 Business Value of Intranets Intranets support Communications and collaboration Business operations and management Web publishing Intranet portal management 25 Extranets Network links that use Internet technologies to connect the intranet of a business to the intranets of another Virtual Private Networks Direct private network links, or private secure Internet links between companies Unsecured Extranet Link between a company and others via the Internet, relying on encryption of sensitive data and firewall security systems 26 Extranet Connectivity 27 Business Value of Extranets Web browser technology makes customer and supplier access to intranets easier and faster Another way to build and strengthen strategic relationships Enables and improves collaboration between a business, customers, and partners Facilitates online, interactive product development and marketing 28 Intranet vs Extranet Part 2 – Telecommunications Network Chapter 6 Telecommunications and Networks 30  Telecommunications Network Components 1 Terminals 2 Telecommunications 3 Telecommunications Any input/output device that uses networks processors channels Devices that support data transmission, Media over which data are transmitted and to transmit or receive data reception between terminals and computers. received 4 Computers 5 Telecommunications Telecommunications monitors (mainframes) are interconnected by Network operating systems (network servers) Web browsers (microcomputers) telecommunications networks so that they can control software carry out their information Controls telecommunications activities. processing assignments. Manages the functions of telecommunications networks 31 Network Component Alternatives 32 Types of Communications Networks Primary types of communications networks Wide Area Metropolitan Area Local Area Virtual Private Client/Server Peer-to-peer 33 Wide Area Network (WAN) Telecommunication network that covers a large geographic area Example: WANs are used by many multinational companies to transmit and receive information among their employees, customers, suppliers, and other organizations across cities, regions, countries, and the world. 34 METROPOLITAN AREA NETWORKS (MAN) When a wide area network optimized a specific geographical area Such networks can range from several blocks of buildings to entire cities. MANs can also depend on communications channels of moderate-to-high data rates. A MAN might be owned and operated by a single organization, but it usually will be used by many individuals and organizations. MANs might also be owned and operated as public utilities. Local Area Network (LAN) Connects computers within a limited physical area, such as an office, classroom, or building 36 Virtual Private Networks (VPN) Used to establish secure intranets and extranets The Internet is the main backbone network Relies on network firewalls, encryption, and other security features to build a “pipe” through the Internet Creates a private network without the high cost of a separate proprietary connection 37 Client/Server Networks Clients End user personal computers or networked computers Servers Used to manage the networks Processing Shared between the clients and servers Sometimes called a two-tier architecture Larger computer systems are being replaced with multiple client/server networks 38 Network Computing Networks are the central computing resource of the organization Thin clients provide a browser-based user interface for processing applets Thin clients include Network computers Net PCs Other low-cost network devices or information appliances 39 Network Computing Application and database servers provide The operating system Application software Applets Databases Database management software Sometimes called a three-tier client/server model because it consists of Thin clients Application servers Database servers 40 Peer-to-Peer Networks Central Server Architecture P2P file-sharing software connects all PCs to a central server When a PC requests a file, the server searches all active peers on the network The server sends the requesting PC a list of links to all active peers who have the file Clicking a link connects the two PCs and automatically transfers the file to the requesting PC Common sites using P2P: ◼ Downloading and trading of files. (file sharing sites) ◼ BitTorrent, Blizzard Entertaiment, PeerCast (Broadcast of Internet radio or TV 41 Peer-to-Peer Networks Pure Peer-to-Peer Architecture No central directory or server File-sharing software connects one PC to another online user When you request a file, the software searches every online user and sends you a list of active file names Clicking a link automatically transfers the file from that user’s hard drive to yours 42 Central Server Peer-to-Peer Networks Advantage Can better protect the integrity and security of the content and users of the network Disadvantage Directory server can be slowed or overwhelmed by too many users or technical problems 43 Summary - Types of Communications Networks Source: Apposite Technologies 44 Telecommunication Network channels Digital and Analog Signals Analog or digital refers to the method used to convert information into an electrical signal Analog: an electrical current is generated that is proportional to the quantity being observed Digital: the quantity being observed is expressed as a number Analog: if the temperature is 83 degrees, a measuring device would generate 8.3 volts Digital: a measurement of 83 degrees would be displayed as the number 83 – based on digits 46 ANALOG and Digital signals https://cdn.sparkfun.com/assets/4/a/e/6/f/51c9c988ce395fab0e000000.png Advantage of Digital signals It can be entered into a computer or a microprocessor and manipulated as desired. If we worked with only analog devices, we would eventually have to convert the output of the analog device into digital form if we wanted to input it into a computer. Because computer networks work primarily with digital signals, most of the hardware used by a computer network is digital. Telecommunications Network media Telecommunications Media ◼ Physically link the devices in a network ◼ Twisted-Pair Wire – most common ◼ Coaxial Cable ◼ Ordinary telephone wire ◼ Sturdy copper or aluminum wire wrapped with spacers to insulate and protect it ◼ Copper wire is twisted into pairs ◼ Transmission speeds can range from 200 – ◼ Transmission speeds can range from 2 Mbps 500 Mbps (unshielded) to 100Mbps (shielded). 50 Telecommunications Media ◼ Fiber-Optic Cable ◼ One or more hair-thin filaments of glass fiber wrapped in a protective jacket ◼ Transmission rates as high as trillions of bits per second (Tbps) ◼ Provide substantial size and weight reductions as well as increased speed and greater carrying capacity. A half-inch-diameter fiber-optic cable can carry more than 500,000 channels, compared with about 5,500 channels for a standard coaxial cable. The Problem of “The Last Mile” Network providers use fiber optic cable as a communications backbone Houses connected to the backbone are wired with twisted pair Users don’t benefit from the faster, better technology Many methods have been offered to solve the problem Cable companies are providing a single-wire solution to many modern households. By using sophisticated technologies, they can bring cable television, Internet access, and telephone services into a home using only the coaxial wire originally put there for cable television. ◼ The telecommunications provider adopts a new, faster, better technology that can provide higher bandwidths and faster telecommunication speeds to consumers. Wireless Technologies Rely on radio wave, microwave, infrared, and visible light pulses to transport digital communications without wires between communications devices. Terrestrial Microwave Earthbound microwave systems transmit high-speed radio signals Follows a line-of-sight path between relay systems spaced about 30 miles apart Communications Satellites Powered by solar panels Serve as relay stations Use microwave radio signals Earth stations use dish antennas to beam signals to the satellites Not suitable for interactive, real-time processing 53 Wireless Technologies Cellular and PCS Telephone and Pager Systems Use several radio communications technologies. Geographic areas are divided into cells Each cell has a low-power transmitter or radio relay antenna to relay calls from one cell to another Computers and other communications processors coordinate and control the transmissions to and from mobile users Wireless LANS Uses wireless radio-wave technology to connect PCs within an office or a building Can be high-frequency, similar to digital cellular, or low frequency (spread spectrum) 54 Wireless Technologies Bluetooth Short-range wireless technology Connects PCs to devices, such as a printer Fairly low cost to implement Other Wireless Systems Cellular phones Mobile radio PDAs Telecommunications networks now play vital and pervasive roles in Web-enabled e-business processes Electronic commerce Enterprise collaboration Other applications that support business operations, management, and strategic objectives 55 The Wireless Web Wireless Internet access is growing as Web-enabled information appliances proliferate Smart telephones, pagers, PDAs All are very thin clients in wireless networks 56 Telecommunications Network processors Telecommunications Processors Modems The most common type of communications processor Converts a digital signal to an analog frequency that can be transmitted over phone lines, then back into a digital signal Modulation and demodulation (modem) 58 Inter-Network Processors Telecommunications networks are interconnected by special-purpose communications processors called internetwork processors Switch… makes connections between telecommunications circuits in a network Router… intelligent communications processor that interconnects networks based on different protocols Hub… a port-switching communications processor Gateway… connects networks with different communications architectures 59 Communications Processors 60 Network Topologies Topology - The structure of a network Star Network - Ties end user computers to a central computer Ring Network - Ties local computer processors together in a ring on a relatively equal basis Bus Network - Local processors share the same communications channel Mesh Network - Uses direct communications lines to connect some or all of the computers in the ring to each other Switch - A message-switching computer that handles data communication between autonomous local computers 61 Network Topologies 62 Bandwidth Bandwidth describes the maximum data transfer rate of a network or Internet connection. The frequency range of a telecommunications channel that determines the maximum transmission rate Speed and capacity typically measured in bits per second (bps) Sometimes call baud rate Transmission Rates Narrow-band = low speed Broadband = high speed 63 Thank you