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 of
Business 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
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
bit
One byte
Synchronous Transmission
Header
Data
Message Packet
Parity Trailer
bit
Transmission Types
Coaxial cable
 Fiber optics
 Wireless
 Microwave
 Satellite
 Cellular

Coaxial
Cable
Microwave Transmission
Repeater
Line of Sight
Line of Sight
Satellite
Transmission
Cellular Communication
Topologies
Ring
 Bus
 Star
 Hierarchical

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
 T1 lines
 Network systems

Network Types
Local Area
Network (LAN)
 Metropolitan Area
Network (MAN)
 Wide Area Network (WAN)
 Internet

Local Area Network
(LAN)
Wide Area Networks (WAN)
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

Mainframe
Application
Client Server
Remote
Access
Server
12 Modems
Printers
Campus FDDI Rings
Mail
Server
Backup
Server SQL
Server
Cisco
Routers
Dial- up
Client
Fax
Server
Wide Area Link 12 Modems
USCS Network
IBS,
Rancho
Cordova
OC-3 Sonet Ring
155mb Bandwidth
IBS,
El Dorado
Hills
USCS,
Rancho
Cordova
128K
Frame
Relay
256K
Frame
Relay
CableData
UK
CableData
Atlanta
CableData
Arkansas
Virtual
Private
CableData,
Network CableData
El Dorado
via Internet Michigan
Hills
USCS Enterprise
Application Architecture
Oracle
Financials
Release 10.7
Oracle 7
RDBMS
IBM
RS/6000
ALEXIS
Corporate
Peoplesoft
Customer
Data
HRMS
Mgmt
Warehouse
Release 6 (Internal App)
(DSS)*
Oracle 7
Oracle 7
Oracle 7
RDBMS
RDBMS
RDBMS
IBM
IBM
IBM
RS/6000
RS/6000
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
