MANAGEMENT INFORMATION SYSTEMS CHAPTER TELECOMMUNICATIONS AND NETWORKING Copyright © 2011 Pearson Education, Inc publishing as Prentice Hall 3-1 PART 1: IT BUILDING BLOCKS Copyright © 2011 Pearson Education, Inc publishing as Prentice Hall 3-2 NETWORKING AND TELECOMMUNICATIONS NETWORKING: The electronic linking of geographically dispersed devices TELECOMMUNICATIONS: Communications at a distance, including voice and data - Also referred to as: data communications, datacom, teleprocessing, telecom, and networking Copyright © 2011 Pearson Education, Inc publishing as Prentice Hall 3-3 OVERVIEW OF TELECOMMUNICATIONS AND NETWORKING • Telecommunications and networking have become increasingly important to businesses because of distributed processing and globalization Copyright © 2011 Pearson Education, Inc publishing as Prentice Hall 3-4 THE TELECOMMUNICATIONS INDUSTRY Three Major Segments of Telecom Industry: • Carriers who own or lease physical plant & sell the service of communications transmission • Equipment vendors who manufacture and sell telecommunications equipment • Service providers who operate and deliver network services or provide access to or deliver services via the Internet Copyright © 2011 Pearson Education, Inc publishing as Prentice Hall 3-5 THE TELECOMMUNICATIONS INDUSTRY Example: AT&T • One of largest carriers in U.S industry • In 1984, AT&T split into several companies as a result of a US Department of Justice antitrust lawsuit • Breakup of AT&T led to greater innovation through competition • But recent trend has been consolidation in the industry Copyright © 2011 Pearson Education, Inc publishing as Prentice Hall 3-6 REASONS FOR NETWORKING Five primary reasons for networking Sharing of technology resources Sharing of data Distributed data processing and client/server systems Enhanced communications Marketing outreach Copyright © 2011 Pearson Education, Inc publishing as Prentice Hall 3-7 REASONS FOR NETWORKING Sharing of technology resources: • • Prior to networking capabilities, computers could not even share printers… Today, PCs share software, mainframes share storage devices, etc Sharing of data: • • • • Enables retrieval of data stored on other nodes in the network Allows efficient transactions between businesses, their suppliers, and their customers, based on up-to-date data Some businesses share many terabytes of data per day Sharing of data via Internet users Copyright © 2011 Pearson Education, Inc publishing as Prentice Hall 3-8 REASONS FOR NETWORKING Distributed data processing and client/server systems: Distributed data processing • Information processing that uses multiple computers at multiple sites that are tied together through telecommunication lines Client/server systems • A type of distributed system in which the processing power is distributed between a central server and a number of client computers Client Copyright © 2011 Pearson Education, Inc publishing as Prentice Hall Transfer of Data Server 3-9 REASONS FOR NETWORKING Enhanced communications: • Telecommunication networks provide the ability to communicate through Email, Bulletin Boards, Blogs, Instant Messaging, Wikis, Social network sites, Videoconferencing • Links between organizations can lead to strategic alliances o o SABRE airline reservation system Electronic data interchange (EDI) Marketing outreach: • Sharing data via the Internet with consumers = an important marketing and sales channel Copyright © 2011 Pearson Education, Inc publishing as Prentice Hall 3-10 NETWORK TYPES - LAN o Wi-Fi (IEEE 802.11) - Short for Wireless Fidelity - Most common wireless LAN type today - Uses a shared Ethernet design - CSMA/CA Protocol • Similar to CSMA/CD, but with less collisions - Commonly used in offices to supplement wired Ethernet networks and support mobile devices, or in areas where adding hardwiring is problematic - Many U.S cities are offering Wi-Fi networks Copyright © 2011 Pearson Education, Inc publishing as Prentice Hall 3-35 NETWORK TYPES o WiMAX (802.16e) - Newest of the network types - Similar to Wi-Fi, but operates over longer distances and at higher speeds - Can use both licensed and non-licensed frequencies - Clearwire = leading vendor at this time Copyright © 2011 Pearson Education, Inc publishing as Prentice Hall 3-36 NETWORK TYPES Wireless Local Area Networks: Some Implementation Problems - More difficult to secure than other network types - Organizations that offer wireless access to entice customers have problems with non-customers or unprofitable customers overusing the network - Unauthorized wireless use is also problematic in condos and apartments Multiple Unsecured Wireless Networks Copyright © 2011 Pearson Education, Inc publishing as Prentice Hall 3-37 NETWORK TYPES Backbone Networks • • Connect LANs Key to internetworking Figure 3.8 Copyright © 2011 Pearson Education, Inc publishing as Prentice Hall 3-38 BACKBONE NETWORK DEVICES Hardware devices for backbone (middle-distance) networks • Hub: Simple device that forwards all messages to every device attached to it • Wireless Access Point: Central device that connects wireless LAN to other networks • Bridge: Connects two LAN segments and only forwards messages that need to go to other segment • Switch: A multiport bridge; connects two or more LAN segments • Router: Connects two ore more LANs and only forwards messages that go to the other LAN Copyright © 2011 Pearson Education, Inc publishing as Prentice Hall 3-39 NETWORK TYPES Wide Area Networks (WANs) • • Similar to LANs, but cover greater distances (“long-haul”) We will consider the following three general types of WANs because they each have advantages and disadvantages: - Switched Circuit - Dedicated Lines Packet-switched Copyright © 2011 Pearson Education, Inc publishing as Prentice Hall 3-40 NETWORK TYPES - WAN Switched Circuit (or circuit-switched): • • A single physical path is temporarily created between two nodes for their exclusive communication Most widely available means of implementing a WAN using a switched circuit connection is to use the ordinary telephone network • Advantages - Easy to set up • Disadvantages - Low speed - High error rates • There are two different pricing schemes available for this service - Direct Distance Dialing (DDD) - pay for usage - Wide Area Telephone Service (WATS) - fixed rate Copyright © 2011 Pearson Education, Inc publishing as Prentice Hall 3-41 NETWORK TYPES - WAN Dedicated Lines: • These are permanent channels exclusive to the business • Advantages - High capacity - Low error rates • • Disadvantages - Expensive Two different types of dedicated circuits: - Leased lines are cable, microwave, or fiber connections - Satellite circuits are popular for organizations with many global locations - SONET lines are high-capacity leased fiber lines Table 3.3 Wide Area Networks Copyright © 2011 Pearson Education, Inc publishing as Prentice Hall 3-42 NETWORK TYPES - WAN Packet-switched: • • • Multiple connections exist simultaneously over the same physical circuit Messages are broken up into packets Businesses use PADs (Packet assembly/disassembly devices) to connect their networks to a common carrier network • Advantages - Efficient use of network - Can be high capacity • Disadvantages - Packets may arrive in different order or with delay Figure 3.9 Copyright © 2011 Pearson Education, Inc publishing as Prentice Hall 3-43 NETWORK TYPES The Internet - Network of networks that use the TCP/IP protocol - Began with ARPANET and NSFNET Similar to an enormous WAN 733 million hosts as of January 2010 • ARPANET (Advanced Research Projects Agency Network) was created by the US Department of Defense • • NSFNET (National Science Foundation Network) was created to link supercomputers for research Each of these were largescale, packet-switching networks that led to the creation of the Internet ARPANET NSFNET Copyright © 2011 Pearson Education, Inc publishing as Prentice Hall 3-44 NETWORK TYPES Internet Applications Copyright © 2011 Pearson Education, Inc publishing as Prentice Hall 3-45 NETWORK TYPES Internet2 - Not-for-profit consortium made up of over 200 universities, as well as industry and government partners, to develop and deploy advanced network applications and technologies for research and commercial purposes Goals Create a leading-edge network capability for the national research community Enable revolutionary Internet applications based on a much higher-performance Internet than we have today Ensure the rapid transfer of new network services and applications to the broader Internet community • • • Copyright © 2011 Pearson Education, Inc publishing as Prentice Hall 3-46 NETWORKING PROTOCOLS • Network Protocols – – An agreed-upon set of rules or conventions governing communication among elements of a network Open Systems Interconnection (OSI) Reference Model • • Skeleton for standards developed by International Organization for Standardization (ISO) Conceptual framework to understand how communications in networks take place Figure 3.11 Copyright © 2011 Pearson Education, Inc publishing as Prentice Hall 3-47 NETWORKING PROTOCOLS • Transmission Control Protocol/Internet Protocol (TCP/IP) • Created to link different types of networks (e.g., satellite and ground packet networks) together into a network of networks • Has become de facto standard protocol for networking -TCP is responsible for the reliable and ordered transmission of messages - IP is responsible for routing individual packets based on their individual addresses (IP addresses) • Roughly corresponds to network and transport layers of OSI model Copyright © 2011 Pearson Education, Inc publishing as Prentice Hall 3-48 NETWORKNG HAS BECOME CRITICAL TO DO BUSINESS • Networking and Telecommunications have become necessary for businesses to function • Increasing access to the Internet in developing countries due to new lines being funded by private and public organizations Impact of cut Internet cables in Middle East - 2008 Copyright © 2011 Pearson Education, Inc publishing as Prentice Hall 3-49