System Connectivity Merle P Martin MIS Department CSU

System Connectivity Merle P. Martin MIS Department CSU Sacramento

Acknowledgements Dr. Russell Ching (MIS Dept) Source Materiel / Graphics t Edie Schmidt (UMS) - Graphic Design t Prentice Hall Publishing (Permissions) u Martin, Analysis and Design of Business Information Systems, 1995 t

Agenda Basic Concepts t Delivery Systems t Open Systems t Distributed Systems t Overall Architecture t

Basic Concepts Definitions t Media t Topologies t Networks t Lines t

Definitions Channel: link by which data / voice linked t Speed: bits per second (bps) u baud rate u mbps - megabytes per second t

Definitions (cont. ) Bandwith: range of frequencies u difference between lowest / highest frequency accommodated on a single channel at the same time t Broadband: more than one signal track over a comm. media t

Analog Signal Voltage Amplitude Frequency 1 Voltage 0 Time Digital Signal 1 0 1 1 0 0 0 Time

Data Communications Digital Signal Analog Signal Modem Digital Signal Modem Phone Lines

Asynchronous Transmission Start bit Parity Stop bit One byte Synchronous Transmission Header Data Parity Trailer bit Message Packet

Transmission Types Coaxial cable u Fiber optics t Wireless u Microwave u Satellite u Cellular t

Coaxial Cable

Microwave Transmission Repeater Line of Sight

Satellite Transmission

Cellular Communication

Topologies Ring t Bus t Star t Hierarchical t

Network Topologies Ring

Network Topologies Bus

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 t T 1 lines t Network systems t

Network Types Local Area Network (LAN) t Metropolitan Area Network (MAN) t Wide Area Network (WAN) t Internet t

Local Area Network (LAN)

Wide Area Networks (WAN)

Internet t Outgrowth of ARPANET u Connect researchers working in the defense industry

T 1 Lines group of 24 voice grade lines t analog messages t 1. 544 mbps t T 2 through T 4 lines t

T-Carrier Bandwiths T 1 - 1. 544 mbps u 24 voice circuits (vc) t T 2 - 6. 312 mbps; 96 vc t T 3 - 44. 736 mbps; 672 vc t T 4 - 139. 264 mbps; 4032 vc t T 5 - ? ? t

Open Systems Standardized interfaces that allow products to interoperate across multivendor systems

Open System Interconnection t International standard (OSI) Seven layers t Standards for each layer t

Surround Development Tactic UNIX A C B UNIX

Distributed Systems Enterprise-wide network of systems that use products from multiple vendors

Should You t Wetherbe’s three questions Distribute? t Are operations interdependent? u does one operation need to know what another operation is doing? u Walmart?

Should You t Are businesses really Distribute? homogeneous? u Fast Food franchises have same processes u Need to know what others are doing? u Are Depart Store franchises same? t Does corporate culture support decentralization?

Creating Overall Architecture t Factors to consider: u Firm’s policy on decentralization u Current computing environment u Policy on standards v more tendency to standards v cleaner overall architecture

Overall Architecture t Factors (cont. ) u How will it serve the business? v follow business and IT plans v Law of the Hammer u Desired level of computing

Level of Computing Corporate WAN t Region, country, division t Site MAN t Department t Work group LAN t Individual t

Packard Bell Distributed u interdependence u homogeneity u culture t FDDI Ring Topology linking mainframes, servers and PCs t PCs have standard software package (e. g. , Office) t Distributed database t

Applicatio Mainframe Client n Server Printers Mail Server Backup Serv er Campus FDDI Rings Cisco Router s Remot e Acces s Server 12 Modem s Dialup Client SQL Server Wide Area Link Fax Server 12 Modems

USCS Network OC-3 Sonet Cable. Da 128 K IBS, Ring ta UK Fram Rancho 155 mb e Cordov Bandwidth Cable. Da Relay USCS, a 256 K ta Ranch Fram Atlanta o e Cable. Da Cordov Relay Virtual ta a IBS, Cable. Dat Private Arkansa Network s Cable. Da El a, El via ta Dorado Internet Michiga Hills n

USCS Enterprise Application Architecture ALEXIS Oracle Peoplesoft ALEXIS Corporate Customer Financials Data HRMS Mgmt Release 6 Warehous (Internal App) e (DSS)* 10. 7 Oracle 7 RDBMS IBM IBM RS/6000 10 mb Ethernet Network for Servers Typical PC Client running Windows 95

Discussion What are some of the problems with connecting “islands of technology? t How does one go about doing that? t Where is connectivity going in business and the public sector t

Discussion Scott Langdoc, Vice President and Chief Information Officer Raleys Food Stores

Points to t Basic Concepts Remember u Definitions Delivery Systems t Open Systems t Distributed Systems t Creating the architecture t