TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY

TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY Lecture 18 TIM 50 Autumn 2012 Tuesday November 27, 2012

Announcement 1. The grades for every assignment will be given in ecommons. 2. It's important to check webpage to get the latest information and assignments changes. Final Exam 1 st Choice December 7, Friday 2 nd Choice December 10, Monday Format is same as Midterm Covering Up to Midterm 25 % After Midterm 75+ %

Review Foundation of business Intelligence Division Oriented Paper File Systems Manual Processing Data redundancy: Data inconsistency: Program data dependence: Lack of flexibility Poor security Lack of data sharing and availability Data Base Systems Relational DB Object Oriented DB DBMS Data Control Data Integrity Data Base System Information Management File Management System File Processing Procedure Data Base Systems DBMS,SQL Intelligence from Collection of Data Information Management Business Applications Data Integrity Control Business Data Maintenances System Inefficiencies Longer Business Cycle No Firm wise Information or Data Access No Data Security No Decision son Integrated Data and inform High Business Process Expenditure Less Redundancy Data Integrity Efficiency Data Confidentiality Data Where house, mart Data Mining DSS, BI

Introduction of Data Processing System Database collection of persistent data from business divisions Database Management System (DBMS) software system that supports creation, population, and querying of a database

The Database Approach to Data Management Database Serves many business applications by centralizing data and controlling redundant data across division boundaries Database management system (DBMS) Interfaces between applications and physical data files Separates logical and physical views of data Solves problems of traditional file environment Controls redundancy Eliminates inconsistency Uncouples programs and data Enables organization to centrally manage data and data security

Advantages of databases Less redundancy Avoidance of Inconsistency Efficiency Data integrity Confidentiality 14.6

Evolution of Database Technologies

Evolution of database systems 2000 and beyond multi tier, client server, Distributed environments, Web based, Content addressable storage, data mining

DATA BASE MODEL OVERVIEW ER Model Hierarchical Model Network Model Relational Model Object Oriented Model(s)

Relational Data Model: summary C a r d i n a l i t y Relation as table Rows = tuples Columns = components Names of columns = attributes Relation name + set of attribute names= schema REL (A 1,A 2,...,A n ) A 1 A 2 A 3... A n a 1 a 2 a 3 a n b 1 b 2 a 3 c n a 1. c 2 b 3 b n.. x 1 v 2 d 3 w n Arity Attributes Tuple Component Set theoretic Domain set of values like a data type Cartesian product (or product) D1 D2... Dn n tuples (V1,V2,...,Vn) s.t., V1 D1, V2 D2,...,Vn Dn Relation=subset of cartesian product of one or more domains FINITE only; empty set allowed Tuples = members of a relation inst. Arity = number of domains Components = values in a tuple Domains corresp. with attributes Cardinality = number of tuples

Advantages of OODBS Designer can specify the structure of objects and their behavior (methods) Multimedia Contents Better interaction with object oriented languages such as Java and C++ Definition of complex and user defined types Encapsulation of operations and user defined methods

Database management system (DBMS) A specific type of software for creating, storing, organizing, and accessing data from a database Separates the logical and physical views of the data Logical view: how end users view data Physical view: how data are actually structured and organized Examples of DBMS: Microsoft Access, DB2, Oracle Database, Microsoft SQL Server, MYSQL

Capabilities of Database Management Systems Data definition capability: Specifies structure of database content, used to create tables and define characteristics of fields Data dictionary: Automated or manual file storing definitions of data elements and their characteristics Data manipulation language(dml): Used to add, change, delete, retrieve data from database

Meta data Data that describes the properties or characteristics of other data Does not include sample data Allows database designers and users to understand the meaning of the data

Structured Query Language (SQL) Microsoft Access user tools for generation SQL Many DBMS have report generation capabilities for creating polished reports (Crystal Reports) Each database will have a set of schemas associated with a catalog. Schema = the structure that contains descriptions of objects created by a user (base tables, views, constraints)

DATABASE DESIGN The design of any database is a lengthy and involved task that can only be done through a step-by-step process. The first step normally involves interviewing potential users of the database. The second step is to build an entity-relationship model (ERM) that defines the entities, the attributes of those entities and the relationship between those entities.

Designing Databases Conceptual (logical) design: Abstract model from business perspective Physical design: How database is arranged on direct access storage devices Design process identifies Relationships among data elements, redundant database elements Most efficient way to group data elements to meet business requirements, needs of application programs Normalization Streamlining complex groupings of data to minimize redundant data elements and awkward many to many relationships

AN UNNORMALIZED RELATION FOR ORDER Example An unnormalized relation contains repeating groups. For example, there can be many parts and suppliers for each order. There is only a one to one correspondence between Order_Number and Order_Date.

NORMALIZED TABLES CREATED FROM ORDER An unnormalized relation contains repeating groups. For example, there can be many parts and suppliers for each order. There is only a one to one correspondence between Order_Number and Order_Date.

Entity relationship diagram Used by database designers to document the data model Illustrates relationships between entities 1:1, 1:N, N:M Relation Diagram

Using Databases to Improve Business Performance and Decision Making Very large databases and systems require special capabilities, tools To analyze large quantities of data To access data from multiple systems Three key techniques 1.Data warehousing 2.Data mining 3.Tools for accessing internal databases through the Web

DATA WAREHOUSES AND DATA MINING Data warehouses support OLAP and decision making Data warehouses do not support OLTP Data mining tools are the tools you use to work with a data warehouse DBMS software = database Data mining tools = data warehouse 3 24

What Is a Data Warehouse? Data warehouse logical collection of information gathered from operational databases used to create business intelligence that supports business analysis activities and decision making tasks 3 25

The Database Approach to Data Management MULTIDIMENSIONAL DATA MODEL The view that is showing is product versus region. If you rotate the cube 90 degrees, the face that will show is product versus actual and projected sales. If you rotate the cube 90 degrees again, you will see region versus actual and projected sales. Other views are possible.

Functions Online transaction processing (OLTP) the gathering of input information, processing that information, and updating existing information to reflect the gathered and processed information Databases support OLTP Operational database databases that support OLTP 3 27

Functions Online analytical processing (OLAP) the manipulation of information to support decision making Databases can support some OLAP Data warehouses only support OLAP, not OLTP Why? Data warehouses are special forms of databases that support decision making 3 28

Data Marts Data warehouses can support all of an organization s information Data marts have subsets of an organizationwide data warehouse Data mart subset of a data warehouse in which only a focused portion of the data warehouse information is kept 3 29

Object in Business Information Systems Business Intelligence(BI): Tools for consolidating, analyzing, and providing access to vast amounts of data to help users make better business decisions E.g., Harrah s Entertainment analyzes customers to develop gambling profiles and identify most profitable customers Principle tools include: Software for database query and reporting Online analytical processing (OLAP) Data mining

More definition

Predictive analysis in Data Mining; Uses data mining techniques, historical data, and assumptions about future conditions to predict outcomes of events E.g., Probability a customer will respond to an offer

Information Vs. Intelligence Analysis, Prediction, Decision Data 3 35

What Are Data Mining Tools? Data mining tools software tools that you use to query information in a data warehouse Query and reporting tools Intelligence agents Multidimensional analysis tools Statistical tools 3 36

3 37 What Are Data Mining Tools?

Converging Disciplines 9 38 Copyright 2010 Pearson Education, Inc. Publishing as Prentice Hall

The EAI Approach Enterprise application integration (EAI) is the use of software and computer systems architectural principles to integrate a set of enterprise computer applications ERP Legacy Application Middleware Legacy Application SCM Database 2 Database 1 Gabriele Piccoli SCM: Supply Chain Management ERP: Enterprise Resource Planning

Gabriele Piccoli CRM Infrastructure

DSS Components Data Management Subsystem DSS database DBMS Data directory Query facility

A Web Based DSS Architecture

Expert Systems vs. DSS Expert System Inject expert knowledge in to a computer system. Automate decision making. The decision environments have structure The alternatives and goals are often established in advance. The expert system can eventually replace the human decision maker. Decision Support System Extract or gain knowledge from a computer system Facilitates decision making Unstructured environment Alternatives may not be fully realized yet Use goals and the system data to establish alternatives and outcomes, so a good decision can be made

Webs, Documents are Data Where House Too

WHAT CAN BUSINESSES LEARN FROM TEXT MINING? Text mining Extracts key elements from large unstructured data sets (e.g., stored e mails) What challenges does the increase in unstructured data present for businesses? How does text mining improve decision making? What kinds of companies are most likely to benefit from text mining software? In what ways could text mining potentially lead to the erosion of personal information privacy?

Web mining Discovery and analysis of useful patterns and information from WWW E.g., to understand customer behavior, evaluate effectiveness of Web site, etc. Web content mining Knowledge extracted from content of Web pages Web structure mining E.g., links to and from Web page Web usage mining User interaction data recorded by Web server

Databases and the Web Many companies use Web to make some internal databases available to customers or partners Typical configuration includes: Web server Application server/middleware/cgi scripts Database server (hosting DBM) Advantages of using Web for database access: Ease of use of browser software Web interface requires few or no changes to database Inexpensive to add Web interface to system

Firms use the Web to make information from their internal databases available to customers and partners Middleware and other software make this possible Database servers CGI(Computer Gateway Interface) Web interfaces provide familiarity to users and savings over redesigning and rebuilding legacy systems

LINKING INTERNAL DATABASES TO THE WEB Users access an organization s internal database through the Web using their desktop PCs and Web browser software.

Managing Data Resources Establishing an information policy Firm s rules, procedures, roles for sharing, managing, standardizing data Data administration: Firm function responsible for specific policies and procedures to manage data Data governance: Policies and processes for managing availability, usability, integrity, and security of enterprise data, especially as it relates to government regulations Database administration: Defining, organizing, implementing, maintaining database; performed by database design and management group

Nature and Quality of Data Basic : True Data Good: Many(File, Record) Better : Organized(Database, Data Where house) Best : Analysis, Intelligence( Data mining, Intelligence)

Chapter TELECOMMUNICATIONS, THE INTERNET, AND WIRELESS TECHNOLOGY

EAI with IT Computer Systems+ Network Architecture + Communications + Business Resource Applications Summary of Previous Network Architecture Internet, Web + Mobile Applications Competitive Advantages in the Business

General Review Fundamentals of Telecommunications Networking Media, Devices, and Software Wireless Telecommunications Technologies Networks and Distributed Computing 55

Main topics Telecommunications Refers to the electronic transmission of signals for communication Networking media, devices, software Types of cables used in telecommunications Twisted pair cables, coaxial cable, and fiber optic cable Networking devices include Modems, network adapters, network control devices, RFID devices, and pagers 56

Main Topics Cellular network Radio network Geographic area is divided into cells with a transceiver antenna (tower) and station at the center of each cell Networks are classified by size PAN, MAN, WAN, GAN Server computers Used to distribute data, files, and programs to users, or clients, on the network Home networks Used to share hardware, files, and a common Internet connection 57

Fundamentals of Telecommunications Communications Transmission of a signal by way of a medium Signal Contains message comprised of data and information Communication medium Anything that carries a signal between a sender and a receiver 58

Telecommunications and Data Communications Telecommunications Electronic transmission of signals for communications Data communications Electronic transmission and reception of digital data Telecommunications network Connects communications and computing devices Networking media Anything that carries an electronic signal 59

Telecommunications and Data Communications Networking media Anything that carries a signal and creates an interface between a sender and receiver Networking hardware devices and networking software work together to enable and control communications signals 60

Characteristics of Telecommunications Analog signal Fluctuates continuously Digital signal Discrete voltage State is either high or low The speed at which a signal can change from high to low is called the signal frequency Bandwidth Data transmission rate Measured in bits per second (bps) 61

62 Characteristics of Telecommunications

Characteristics of Telecommunications Broadband or high speed Internet Connection that is always on or active Faster than dial up Narrowband Any medium with a speed less than 200 Kbps 63

Networking Media Physical Cables Twisted pair cable Consists of pairs of twisted wires covered with an insulating layer Coaxial cable Consists of an inner conductor wire surrounded by insulation, a conductive shield, and a cover Fiber optic cable Consists of thousands of extremely thin strands of glass or plastic bound together in a sheathing 64

65 Networking Media Physical Cables

Networking Media Physical Cables Fiber optic cable has several advantages over traditional copper cable Speed Size Clarity Security 66

Radio Signals and Light Radio wave Electromagnetic wave transmitted through an antenna at different frequencies FCC assigns different frequencies for different devices Microwaves Sent at the high end of the spectrum (1 300 GHz) 67

68 Networking Devices

Networking Devices Modems Modulates and demodulates signals Cable modem Provides Internet access over a cable television network DSL modem Provides high speed Internet service over telephone lines Network adapter Computer circuit board, PC Card, or USB device Network interface card (NIC) Wireless adapters 69

Network Control Devices Hubs Used as a central point for connecting a series of computers Switches Fundamental part of most networks Allow several users to send information at the same time without slowing the network Repeaters Connect multiple network segments Bridges Connect two or more network segments 70

Network Control Devices Gateways Network points that act as an entrance to another network Routers Can divide a single network into two logically separate networks Wireless access point Receives and transmits data to wireless adapters Firewall Device or software that filters the information coming onto a network, generally to increase security and remove unwanted traffic 71

FUNCTIONS OF THE MODEM A modem is a device that translates digital signals into analog form (and vice versa) so that computers can transmit data over analog networks such as telephone and cable networks.

MODEMS An illustration of data sent using a modem and a regular telephone line. A modem is a device that converts digital data originating from a terminal or computer, to analog signals used by voice communication networks such as the telephone system. At one end, modems convert the digital pulses to audible tones and convert audio tones back to digital pulses at the other. The word "Modem" stands for "MOdulator DEModulator". Networks for Beginners: http://compnetworking.about.com/

MODEMS Transmission speed Modems are available in different transmission speeds, which are measured in BPS (bits per second) also called BAUD rate. Standard modems speeds: 9600 baud, 14400 baud, 28800 baud, 33600 baud, 56800 baud. Internal/External Internal modems are electronic cards. An internal modem is installed in one of the computer's expansion slot. External modems are fully functioning external devices. The external modem is connected to a computer using a serial cable to one of the computer's serial ports, and draws power from an external power source. Networks for Beginners: http://compnetworking.about.com/

HUBS The original Ethernet LANs relied on certain physical characteristics of the cable carrying the network data (usually coaxial cable). New Ethernet technologies introduced new cable types that we unable to fulfill the original physical requirements. New devices hubs were introduced to simulate those characteristics. Simply put, the hub's major function is to replicate data it receives from one device attached to it to all others. Networks for Beginners: http://compnetworking.about.com/

REPEATERS A repeater is connected to two cable segments. Any electrical signal reaching the repeater from one segment, will be amplified and retransmitted to the other segment. A common problem in the networking world is that of weakening electrical signals. Electrical signals traveling through wires (such as copper wires used in most networks), weaken due to the wire's electrical resistance. This effect limits the lengths of the cable that can be used. A repeater will overcome this limit, when there is a need to connect two computers at a larger distance. An illustration of a repeater at work The electrical signal entering the repeater at one end is weakened. The repeater amplifies the electrical signals and resends the data. Networks for Beginners: http://compnetworking.about.com/

ROUTERS Routers connect two or more networks and forward data packets between them. When data arrives from one of the segments, the router decides, according to it's routing table, to which segment to forward that data. Networks for Beginners: http://compnetworking.about.com/

GATEWAY "Gateway" is a term that was once used to refer to a routing device. Today, in the TCP/IP world, the term "router" is used to describe such a device. The term gateway now refers to special purpose devices, that perform protocol conversions. Gateways implement application layer conversions of information received from various protocols. Examples of gateways found on today's markets are: VocalTec Gateway: A gateway that converts human speech traveling on analog phone lines into local area network protocol data, and visaversa. RadVision Gateway: Converts video from digital phone lines into local area network protocol data, and visa versa. Networks for Beginners: http://compnetworking.about.com/

Firewalls Firewall A machine and its software that serve as a special gateway to a network, protecting it from inappropriate access Filters the network traffic that comes in, checking the validity of the messages as much as possible and perhaps denying some messages altogether Enforces an organization s access control policy 15 79

Firewalls 15 80 Figure 15.8 A firewall protecting a LAN

EXAMPLE OF FIREWALL Firewalls are systems that establish access control policies among networks. They can block information from entering a network or from getting out of that network, they can permit different users to perform different kinds of operations, according to the user's authorizations. Networks for Beginners: http://compnetworking.about.com/

Industrial Telecommunications Media and Devices Microwave transmission Also called terrestrial microwave Line of sight medium Communications satellite Basically a microwave station placed in outer space 82

Networking Software Networking software Monitors the load, or amount of traffic, on the network Provides error checking and can often indicate problems and possible solutions Can provide data security and privacy Network administrator or systems administrator Person responsible for setting up and maintaining the network 83

Wireless Fidelity and WiMAX Wireless fidelity (Wi Fi) Makes use of access points to wirelessly connect users to networks within a range of 250 1000 feet (75 300 meters) WiMAX Known as IEEE 802.16 Faster and longer range than Wi Fi WiMAX antenna has 31 mile range Perfect for city wide Internet access 84

Bluetooth Enables digital devices to communicate directly with each other wirelessly over short distances Communicates at speeds of up to 1 Mbps within a range of up to 33 feet (10 meters) Can connect devices to a computer network using access points like Wi Fi 85

Radio Frequency Identification (RFID) Uses tiny transponders in tags that can be Attached to merchandise or other objects Read using an RFID transceiver or reader for the purpose of identification Primarily used to track merchandise from supplier to retailer to customer 86

Computer Networking Concepts Nodes Devices attached to a network Workstations Computers attached to a network Local resources Files, drives, or other peripheral devices connected to the workstation and accessible via the network Network or remote resources Workstation accesses over the network Transparency provides user friendly environment 87

Distributed Computing Distributed Computing Multiple remote computers working together Database servers Store databases and respond to queries File servers Store files and deliver them to users upon request Application servers Store programs and deliver them to desktops when users click the icon 88

Distributed Computing Blade computing Cheaper alternative Takes advantage of the fact that at any one time, 30% of system PCs are not being used PCs are replaced with thin clients Keyboard, mouse, display, unit to connect the device to the server Thin clients cost less than half the cost of a PC 89

A blade server is a stripped down server computer with a modular design optimized to minimize the use of physical space and energy. IBM HS20 blade server

91 Distributed Computing

Network Types Personal area network (PAN) Interconnecting personal information technology devices Typically wireless Local Area Network (LAN) Connects computer systems within same building Can use various designs or topologies Intranet Uses protocols of the Internet and the Web within the confines of a private network Virtual Private Network (VPN) Enables private Internet communications 92

Network Types Metropolitan area network (MAN) Connects networks within a city or metropolitan size area into a larger high speed network Wide area network (WAN) Connects LANs and MANs between cities, across country, and around the world Global Networks A WAN that crosses an international border (transborder data flow) Data havens have few restrictions on telecommunications or databases Electronic Data Interchange (EDI) Connects corporate computer systems 93

94 Network Types

95 Network Types

Hyundai Heavy Industries Creates A Wireless Shipyard Problem: Shipbuilding space is too large (4.2 sq mi) and complex to track inventory in real time, limiting efficiency Solution: High speed wireless network built by KT Corp, using radio sensors, notebooks, mobiles, Web cams Illustrates: Powerful capabilities and solutions offered by contemporary networking technology Use of radio sensor technologies to track inventory

Telecommunications and Networking in Today s Business World Networking and communication Trends Convergence: Telephone networks and computer networks converging into single digital network using Internet standards E.g. cable companies providing voice service Broadband: More than 60% U.S. Internet users have broadband access Broadband wireless: Voice and data communication as well as Internet access are increasingly taking place over broadband wireless platforms

What is a computer network? Two or more connected computers Major components in simple network Client computer Server computer Network interfaces (NICs) Connection medium Network operating system Hub or switch Routers Device used to route packets of data through different networks, ensuring that data sent gets to the correct address

COMPONENTS OF A SIMPLE COMPUTER NETWORK Illustrated here is a very simple computer network, consisting of computers, a network operating system residing on a dedicated server computer, cable (wiring) connecting the devices, network interface cards (NICs), switches, and a router.

Components of networks in large companies Hundreds of local area networks (LANs) linked to firm wide corporate network Various powerful servers Web site Corporate intranet, extranet Backend systems Mobile wireless LANs (Wi Fi networks) Videoconferencing system Telephone network Wireless cell phones

CORPORATE NETWORK INFRASTRUCTURE Today s corporate network infrastructure is a collection of many different networks from the public switched telephone network, to the Internet, to corporate local area networks linking workgroups, departments, or office floors.

Key networking technologies Client/server computing Distributed computing model Clients linked through network controlled by network server computer Server sets rules of communication for network and provides every client with an address so others can find it on the network Has largely replaced centralized mainframe computing The Internet: Largest implementation of client/server computing

Protocols Protocol: set of rules governing communication between computers Some protocols are designed for WANs, LANs, and wireless communications Most important set of protocols for telecommunications and networks is called TCP/IP Management Information Systems, Sixth Edition 103

Key networking technologies (cont.) TCP/IP and connectivity Connectivity between computers enabled by protocols Protocols: Rules that govern transmission of information between two points Transmission Control Protocol/Internet Protocol (TCP/IP) Common worldwide standard that is basis for Internet Department of Defense reference model for TCP/IP Four layers 1. Application layer 2. Transport layer 3. Internet layer 4. Network interface layer

TCP/IP TCP/IP (Transmission Control Protocol/ Internet Protocol): a set of related protocols TCP ensures packets arrive accurately and in proper order IP ensures efficient delivery of packets from node to node Internet backbone: highest speed channels Host: a computer connected directly to a backbone IP number: unique numerical identification for a network device Management Information Systems, Sixth Edition 105

TCP/IP (continued) DNS (Domain Name Service): associates a character based name with an IP address Static IP address: a permanent address assigned to a device Dynamic IP address: temporary IP number assigned to a device for the duration of the connection Provides flexibility when the number of IP addresses is limited Management Information Systems, Sixth Edition 106

Ethernet Ethernet: LAN protocol using coaxial or Cat 5 or 6 twisted pair cable Gigabit Ethernet: faster Ethernet connection of one Gbps or greater Devices on network contend with other devices for transmission time CSMA/CD (Carrier Sense Multiple Access with Collision Detection) protocol ensures there are no collisions in transmission Management Information Systems, Sixth Edition 107

Wireless Protocols IEEE 802.11: a family of wireless protocols known as Wi Fi (Wireless Fidelity) Supports wireless communication within 100 meters of router 802.11 subtypes support various distances and speeds up to 248 Mbps Access point (hotspot): connection between wireless device and a wired network Allows Internet access within range of equipment Management Information Systems, Sixth Edition 108

Wireless Protocols (continued) Encryption: ability to scramble and encode messages Uses encryption keys shared only between sender and receiver Bluetooth: allows devices to communicate within 10 meters Transmits voice and data Considered a PAN technology Management Information Systems, Sixth Edition 109

Key networking technologies (cont.) Packet switching Method of slicing digital messages into parcels (packets), sending packets along different communication paths as they become available, and then reassembling packets at destination Previous circuit switched networks required assembly of complete point topoint circuit Packet switching more efficient use of network s communications capacity

Packet Switching To improve the efficiency of transferring information over a shared communication line, messages are divided into fixedsized, numbered packets Network devices called routers are used to direct packets between networks Figure 15.4 Messages sent by packet switching 15-18

PACKED SWITCHED NETWORKS AND PACKET COMMUNICATIONS Data are grouped into small packets, which are transmitted independently over various communications channels and reassembled at their final destination.

THE TRANSMISSION CONTROL PROTOCOL/ INTERNET PROTOCOL (TCP/IP) REFERENCE MODEL This figure illustrates the four layers of the TCP/IP reference model for communications

Signals: digital vs. analog Modem: Translates digital signals into analog form Types of networks Local area networks (LANs) Campus area networks (CANs) Peer to peer Topologies: star, bus, ring Metropolitan and wide area networks Wide area networks (WANs) Metropolitan area networks (MANs)

NETWORK TOPOLOGIES NETWORK TOPOLOGIES The three basic network topologies are the star, bus, and ring.

Physical transmission media Twisted wire (modems) Coaxial cable Fiber optics and optical networks Dense wavelength division multiplexing (DWDM) Wireless transmission media and devices Microwave Satellites Cellular telephones Transmission speed (hertz, bandwidth)

BP S SATELLITE TRANSMISSION SYSTEM Communication satellites help BP transfer seismic data between oil exploration ships and research centers in the United States.

What is the Internet? Internet Addressing and Architecture The Domain Name System Hierarchical structure Top level domains Internet Architecture and Governance No formal management: IAB, ICANN, W3C The Future Internet: IPv6 and Internet2

Network Addresses Hostname A unique identification that specifies a particular computer on the Internet For example matisse.csc.villanova.edu condor.develocorp.com 15 119

Network Addresses Network software translates a hostname into its corresponding IP address For example 205.39.145.18 15 120

Network Addresses An IP address can be split into network address, which specifies a specific network host number, which specifies a particular machine in that network Figure 15.9 An IP address is stored in four bytes 15 121

Domain Name System A hostname consists of the computer name followed by the domain name csc.villanova.edu is the domain name A domain name is separated into two or more sections that specify the organization, and possibly a subset of an organization, of which the computer is a part Two organizations can have a computer named the same thing because the domain name makes it clear which one is being referred to 15 122

Domain Name System The very last section of the domain is called its toplevel domain (TLD) name Figure 15 123 15.10 Top-level domains, including some relatively new ones

Domain Name System Organizations based in countries other than the United States use a top level domain that corresponds to their two letter country codes Some of the top-level domain names based on country codes 15 124

Domain Name System The domain name system (DNS) is chiefly used to translate hostnames into numeric IP addresses DNS is an example of a distributed database If that server can resolve the hostname, it does so If not, that server asks another domain name server 15 125

The Global Internet THE DOMAIN NAME SYSTEM Domain Name System is a hierarchical system with a root domain, top level domains, second level domains, and host computers at the third level.

Internet Connections Internet backbone A set of high speed networks that carry Internet traffic These networks are provided by companies such as AT&T, GTE, and IBM Internet service provider (ISP) A company that provides other companies or individuals with access to the Internet 15 127

Internet Connections There are various technologies available that you can use to connect a home computer to the Internet A phone modem converts computer data into an analog audio signal for transfer over a telephone line, and then a modem at the destination converts it back again into data A digital subscriber line (DSL) uses regular copper phone lines to transfer digital data to and from the phone company s central office A cable modem uses the same line that your cable TV signals come in on to transfer the data back and forth 15 128

Internet Connections Broadband A connection in which transfer speeds are faster than 128 bits per second DSL connections and cable modems are broadband connections The speed for downloads (getting data from the Internet to your home computer) may not be the same as uploads (sending data from your home computer to the Internet) 15 129

Open Systems Proprietary system A system that uses technologies kept private by a particular commercial vendor One system couldn t communicate with another, leading to the need for Interoperability The ability of software and hardware on multiple machines and from multiple commercial vendors to communicate Leading to Open systems Systems based on a common model of network architecture and a suite of protocols used in its implementation 15 130

Open Systems Figure 15.5 The layers of the OSI Reference Model The International Organization for Standardization (ISO) established the Open Systems Interconnection (OSI) Reference Model Each layer deals with a particular aspect of network communication 15 131

Network Protocols Network protocols are layered such that each one relies on the protocols that underlie it Sometimes referred to as a protocol stack Layering of key network protocols 15 132

TCP/IP TCP stands for Transmission Control Protocol TCP software breaks messages into packets, hands them off to the IP software for delivery, and then orders and reassembles the packets at their destination IP stands for Internet Protocol IP software deals with the routing of packets through the maze of interconnected networks to their final destination 15 133

TCP/IP (cont.) UDP stands for User Datagram Protocol It is an alternative to TCP The main difference is that TCP is highly reliable, at the cost of decreased performance, while UDP is less reliable, but generally faster 15 134

High Level Protocols Other protocols build on the foundation established by the TCP/IP protocol suite Simple Mail Transfer Protocol (SMTP) File Transfer Protocol (FTP) Telnet Hyper Text Transfer Protocol (http) 15 135

The Global Internet INTERNET NETWORK ARCHITECTURE The Internet backbone connects to regional networks, which in turn provide access to Internet service providers, large firms, and government institutions. Network access points (NAPs) and metropolitan area exchanges (MAEs) are hubs where the backbone intersects regional and local networks and where backbone owners connect with one another.

THE BATTLE OVER NET NEUTRALITY What is network neutrality? Why has the Internet operated under net neutrality up to this point in time? Who s in favor of net neutrality? Who s opposed? Why? What would be the impact on individual users, businesses, and government if Internet providers switched to a tiered service model? Are you in favor of legislation enforcing network neutrality? Why or why not?

Internet services E mail Chatting and instant messaging Newsgroups Telnet File Transfer Protocol (FTP) World Wide Web VoIP Virtual private network (VPN)

CLIENT/SERVER COMPUTING ON THE INTERNET Client computers running Web browser and other software can access an array of services on servers over the Internet. These services may all run on a single server or on multiple specialized servers.

HOW VOICE OVER IP WORKS An VoIP phone call digitizes and breaks up a voice message into data packets that may An VoIP phone call digitizes and breaks up a voice message into data packets that may travel along different routes before being reassembled at the final destination. A processor nearest the call s destination, called a gateway, arranges the packets in the proper order and directs them to the telephone number of the receiver or the IP address of the receiving computer.

A VIRTUAL PRIVATE NETWORK USING THE INTERNET This VPN is a private network of computers linked using a secure tunnel connection over the Internet. It protects data transmitted over the public Internet by encoding the data and wrapping them within the Internet Protocol (IP). By adding a wrapper around a network message to hide its content, organizations can create a private connection that travels through the public Internet.

MONITORING EMPLOYEES ON NETWORKS: UNETHICAL OR GOOD BUSINESS? Should managers monitor employee e mail and Internet usage? Why or why not? Describe an effective e mail and Web use policy for a company. Should managers inform employees that their Web behavior is being monitored? Or should managers monitor secretly? Why or why not?

The World Wide Web HTML (Hypertext Markup Language): Formats documents for display on Web Hypertext Transfer Protocol (HTTP): Communications standard used for transferring Web pages Uniform resource locators (URLs): Addresses of Web pages E.g. http://www.megacorp.com/content/features/082602.ht ml Web servers Software for locating and managing Web pages

The World Wide Web (cont.) Search engines Started in early 1990s as relatively simple software programs using keyword indexes Today, major source of Internet advertising revenue via search engine marketing, using complex algorithms and page ranking techniques to locate results Shopping bots Use intelligent agent software for searching Internet for shopping information

HOW GOOGLE WORKS The Google search engine is continuously crawling the Web, indexing the content of each page, calculating its popularity, and storing the pages so that it can respond quickly to user requests to see a page. The entire process takes about one half second.

TOP U.S. WEB SEARCH ENGINES Google is the most popular search engine on the Web, handling 72 percent of all Web searches

Web 2.0 Four defining features 1. Interactivity 2. Real time user control 3. Social participation 4. User generated content Technologies and services behind these features Cloud computing Blogs/RSS Mashups & widgets Wikis Social networks

Web 3.0 the Seman c Web Effort of W3C to add meaning to existing Web Make searching more relevant to user Other visions More intelligent computing 3D Web Pervasive Web Increase in cloud computing, SaaS Ubiquitous connectivity between mobile and other access devices Make Web a more seamless experience

Cellular systems Competing standards for cellular service CDMA: United States GSM: Rest of world, plus AT&T and T Mobile Third generation (3G) networks Suitable for broadband Internet access 144 Kbps 2Mbps 4G networks Entirely packet switched 100 Mbps 1Gbps

Wireless computer networks and Internet access Bluetooth (802.15) Links up to 8 devices in 10 m area Useful for personal networking (PANs) and in business to transmit data from handheld devices to other transmitters Wi Fi (802.11) Set of standards: 802.11a, 802.11b, 802.11g, 802.11n Used for wireless LAN and wireless Internet access Use access points: Device with radio receiver/transmitter for connecting wireless devices to a wired LAN

The Wireless Revolution A BLUETOOTH NETWORK (PAN) Bluetooth enables a variety of devices, including cell phones, PDAs, wireless keyboards and mice, PCs, and printers, to interact wirelessly with each other within a small 30 foot (10 meter) area. In addition to the links shown, Bluetooth can be used to network similar devices to send data from one PC to another, for example.

AN 802.11 WIRELESS LAN The Wireless Revolution Mobile laptop computers equipped with network interface cards link to the wired LAN by communicating with the access point. The access point uses radio waves to transmit network signals from the wired network to the client adapters, which convert them into data that the mobile device can understand. The client adapter then transmits the data from the mobile device back to the access point, which forwards the data to the wired network.

Wireless computer networks and Internet access Wi Fi (cont.) Hotspots: Access points in public place to provide maximum wireless coverage for a specific area Weak security features WiMax (802.16) Wireless access range of 31 miles Require WiMax antennas Sprint Nextel building WiMax network as foundation for 4G networks

Radio frequency identification (RFID) Use tiny tags with embedded microchips containing data about an item and location, and antenna Tags transmit radio signals over short distances to special RFID readers, which send data over network to computer for processing Active RFID: Tags have batteries, data can be rewritten, range is hundreds of feet, more expensive Passive RFID: Range is shorter, also smaller, less expensive, powered by radio frequency energy

Radio frequency identification (RFID) (cont.) Common uses: Automated toll collection Tracking goods in a supply chain Requires companies to have special hardware and software Reduction in cost of tags making RFID viable for many firms

HOW RFID WORKS RFID uses low powered radio transmitters to read data stored in a tag at distances ranging from 1 inch to 100 feet. The reader captures the data from the tag and sends them over a network to a host computer for processing.

Wireless sensor networks (WSNs) Networks of hundreds or thousands of interconnected wireless devices embedded into physical environment to provide measurements of many points over large spaces Devices have built in processing, storage, and radio frequency sensors and antennas Require low power, long lasting batteries and ability to endure in the field without maintenance Used to monitor building security, detect hazardous substances in air, monitor environmental changes, traffic, or military activity

A WIRELESS SENSOR NETWORK The small circles represent lower level nodes and the larger circles represent highend nodes. Lower level nodes forward data to each other or to higherlevel nodes, which transmit data more rapidly and speed up network performance.

Radio Frequency Identification RFID tags are tiny and need little power Objects are embedded with tags that contain a transponder (a radio transceiver activated by a signal transmitted to it) Tags are encoded with electronic product code Readers decode data stored in tag s memory and pass the data to a host computer Efficient for large companies, but expensive for smaller companies Management Information Systems, Sixth Edition 159

Management Information Systems, Sixth Edition 160

Management Information Systems, Sixth Edition 161

Converging Technologies Convergence occurs in networking technology Cell phones can act as Web phones using VoIP Television sets will connect to Internet, cable, and satellites concurrently PDAs function as televisions sets and phones Portable music/video players will communicate with PCs to download files and transmit to wireless earphones Cell phones will read RFID on products to compare prices and make purchases Management Information Systems, Sixth Edition 162

Summary Telecommunications is communication over distance Telecommunications technology has changed the business environment Different media have different bandwidths Networks are classified according to reach and complexity Public network can be turned into a virtual private network (VPN) Management Information Systems, Sixth Edition 163

Summary (continued) Two ways to switch a communication line: packet switching and circuit switching Network protocols are sets of rules to which all devices on a network must adhere The Internet adheres to the TCP/IP protocol Wireless technologies make it easy and affordable to create wireless LANs and hotspots Organizations and individuals have variety of choices when subscribing to networking services Management Information Systems, Sixth Edition 164

Summary (continued) As Internet links become faster, Internet telephony (VoIP) is gaining in popularity Wireless technologies support the increasingly popular RFID technologies Much like hardware, telecommunications technologies are merging Increasing numbers of employees now telecommute Management Information Systems, Sixth Edition 165

Telecommunications and Networking in today s Business World Networking and Communication Trends What is a Computer Network? Key Digital Networking Technologies Communications Networks Signals Digital VS. Analog Types of Networks Physical Transmission Media The Global Internet What is the Internet? Internet Addressing and Architecture Internet Services and Communication Tools The Wireless Revolution Cellular Systems Wireless computer Networks and internet Access RIFID and Wireless Sensor Networks