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System Connectivity. Merle P. Martin MIS Department CSU Sacramento. Acknowledgements. Dr. Russell Ching ( MIS Dept ) Source Materiel / Graphics Edie Schmidt ( UMS ) - Graphic Design Prentice Hall Publishing (Permissions)
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System Connectivity Merle P. Martin MIS Department CSU Sacramento
Acknowledgements • Dr. Russell Ching (MIS Dept) Source Materiel / Graphics • Edie Schmidt (UMS) - Graphic Design • Prentice Hall Publishing (Permissions) • Martin, Analysis and Design ofBusiness Information Systems, 1995
Agenda • Basic Concepts • Delivery Systems • Open Systems • Distributed Systems • Overall Architecture
Basic Concepts • Definitions • Media • Topologies • Networks • Lines
Definitions • Channel: link by which data / voice linked • Speed: bits per second (bps) • baud rate • mbps - megabytes per second
Definitions (cont.) • Bandwith: range of frequencies • difference between lowest / highest frequency accommodated on a single channel at the same time • Broadband: more than one signal track over a comm. media at the same time
Analog Signal Voltage Amplitude Time Frequency Digital Signal 1 Voltage 0 Time 1 0 1 1 0 0 0
Data Communications Digital Signal Analog Signal Digital Signal Modem Modem Phone Lines
Asynchronous Transmission Start Parity Stop bit bit bit One byte Synchronous Transmission Parity Header Data Trailer bit Message Packet
Transmission Types • Coaxial cable • Fiber optics • Wireless • Microwave • Satellite • Cellular
Microwave Transmission Repeater Line of Sight Line of Sight
Topologies • Ring • Bus • Star • Hierarchical
Network Topologies Ring
Network Topologies Star
Network Topologies Hierarchical
Issue Should a firm: stay at the forefront of telecomm technology lest it fall seriously behind OR let other firms go first and learn from their mistakes?
Delivery Systems • Network types • T1 lines • Network systems
Network Types • Local Area Network (LAN) • Metropolitan Area Network (MAN) • Wide Area Network (WAN) • Internet
Internet • Outgrowth of ARPANET • Connect researchers working in the defense industry
T1 Lines • group of 24 voice grade lines • analog messages • 1.544 mbps • T2 through T4 lines
T-Carrier Bandwiths • T1 - 1.544 mbps • 24 voice circuits (vc) • T2 - 6.312 mbps; 96 vc • T3 - 44.736 mbps; 672 vc • T4 - 139.264 mbps; 4032 vc • T5 - ????
Open Systems Standardized interfaces that allow products to interoperate across multivendor systems
Open System Interconnection (OSI) • International standard • Seven layers • Standards for each layer
Surround Development Tactic UNIX A C B UNIX
Distributed Systems Enterprise-wide network of systems that use products from multiple vendors
Should You Distribute? • Wetherbe’s three questions • Are operations interdependent? • does one operation need to know what another operation is doing? • Walmart?
Should You Distribute? • Are businesses really homogeneous? • Fast Food franchises have same processes • Need to know what others are doing? • Are Depart Store franchises same? • Does corporate culture support decentralization? • Aerospace Industry
Creating Overall Architecture • Factors to consider: • Firm’s policy on decentralization • Current computing environment • Policy on standards • more tendency to standards • cleaner overall architecture
Overall Architecture • Factors (cont.) • How will it serve the business? • follow business and IT plans • Law of the Hammer • Desired level of computing
Level of Computing • Corporate • Region, country, division • Site • Department • Work group • Individual WAN MAN LAN
Packard Bell • Distributed • interdependence • homogeneity • culture • FDDI Ring Topology linking mainframes, servers and PCs • PCs have standard software package (e.g., Office) • Distributed database
Application Server Mainframe Remote Access Server Client 12 Modems Printers Dial- up Client Campus FDDI Rings MailServer Cisco Routers Fax Server Backup Server SQL Server Wide Area Link 12 Modems
USCS Network IBS, Rancho Cordova OC-3 Sonet Ring 155mb Bandwidth CableData UK 128KFrame Relay CableData Atlanta USCS, Rancho Cordova 256K Frame Relay CableData Arkansas Virtual Private Network via Internet IBS, El Dorado Hills CableData, El Dorado Hills CableData Michigan
USCS Enterprise Application Architecture ALEXIS Customer Mgmt (Internal App) Corporate Data Warehouse (DSS)* Peoplesoft HRMS Release 6 Oracle Financials Release 10.7 Oracle 7 RDBMS Oracle 7 RDBMS Oracle 7 RDBMS Oracle 7 RDBMS IBM RS/6000 IBM RS/6000 IBM RS/6000 IBM RS/6000 10mb Ethernet Network for Servers Typical PC Client running Windows 95
Discussion • What are some of the problems with connecting “islands of technology? • How does one go about doing that? • Where is connectivity going in business and the public sector
Discussion Scott Langdoc, Vice President and Chief Information Officer Raleys Food Stores
Points to Remember • Basic Concepts • Definitions • Delivery Systems • Open Systems • Distributed Systems • Creating the architecture