Evolution of PC_LANS and Networks

1
Evolution of PC_LANS and Networks

• Prithvi N. Rao
• Carnegie Mellon University

2
Objectives

• Describe the evolution of corporate management
  structures.
• List the characteristics of a centralized network
  system.
• Recognize the challenges of building an
  enterprise-wide network.
• List some of the critical issues facing network
  managers.

3
Introduction

• Communication is fundamental to organizational
  effectiveness.
• Management structure determines structural
  requirements for communication.
• Evolution from function oriented steep
  hierarchies to flatter process focused
  structures.
• Functional structures require hierarchical
  communication based on centralized architectures.
• Process structures require more de-centralized
  communication.

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Steep Functional Hierarchy
Manufacturing Sales
Executive Management Executive Management
Senior Management Senior Management
Middle Management Middle Management
Staff Staff
Line Line
5
Flat Process Orientation
Executive Management
Project Leader
Team Members Sales/Marketing/Mfg./Operations/Customer Svc.
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Introduction

• Effective organizations must have a communication
  system that links all of its resources people,
  information and tools.
• Evolution of roles increases the importance of
  communications.
• Creates new demands on systems for supporting
  complex organizations and communications
  requirements.
• Computers link people, information and tools.
• Meet flat process structural standard.
• Vendors must communicate with each other.
• Software tool compatibility is important.

7
Evolution

• Networks facilitate effective communicate using
  computers.
• Information on networked computers must be
  accessible.
• Vendors work closely with customers and each
  other to ensure that an open communications
  environment is maintained.
• Open environment facilitates the use of
  heterogeneous hardware and software
  infrastructures as well as various types of
  cabling.
• Network operating systems facilitate sharing.
• Database Systems, Electronic mail systems
  facilitate sharing.

8
Computer System Evolution

• Move towards smaller, faster, cheaper hardware.
• PCs are getting cheaper and faster
• Memory speed is increasing.
• Applications are demanding more resources.
• Audio, Video, Speech.
• Operating systems have also evolved.
• Operating systems cannot keep up with hardware
  advances.
• Result over 20 years is inversion of
  cost/performance.
• Vacuum tube -gt high cost, low performance.
• VLSI -gt low cost, high performance.

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Computer System Evolution

• Evolution of computer systems occurred in
  distinct phases

Phase Type of MIS Environment Equipment Justification
Phase 1 Centralized Mainframes Organizational-wide Functional Automation
Phase 2 Distributed/Departmental PCs/Minis Personal/Departmental Effectiveness
Phase 3 Distributed/Enterprise Networks Workgroup Productivity
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Mainframe Architecture

• Mainframe based network systems were centralized.
• Tightly controlled of computer and shared
  peripherals.
• Terminal devices connected (dumb terminals).
• Star networking design.
• Few computer to computer integration
  requirements.

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Mainframe Architecture
Channel-to-Channel
Mainframe
Mainframe
Or Link Attached
Channel-to-Channel
FEP
FEP
Or Link Attached
Dumb Terminals
12
Distributed Networks

• First networks enabled simple file and resource
  sharing (printers).
• PC networks used originally to support
  communication at departmental level.
• PC networks contrasted mainframe phase
• Local area network
• Shared resources data, programs, peripherals
• Distributed processing
• Intelligent workstations
• Bus or ring network topology

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Network Topology Token Ring
Shared Resource (printers)
Server
PC
PC
Token Ring
PC
14
Network Topology Ethernet
WS
WS
Ethernet
Thinnet 185 meters (600 feet)
terminator
terminator
Thicknet 500 meters (1700 feet)
WS
WS
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Enterprise Networking

• Places tremendous demands on the communication
  systems within organization.
• Cause is related to rising importance of
  networking multiple systems
• New demands that must be addressed are
• Increasing importance of wide are networking
• Combining LAN and WAN technologies
• Support for multi-protocol based networks
• Multiple topology networks
• Application interface requirements

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Enterprise Networking

• Networking technology plays a major role in
  corporate communication
• Information technology managers faced with
  numerous issues
• Continued expansion of current networks
• Increased interconnectivity requirements
• Distributed applications
• Client Server based computing
• Importance of open systems standards
• Managing the network

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Enterprise Networking
Remote
WAN
Remote Bus
Local Bus
Local Ring
Mainframe
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Current Network Management
Network Manager Support System
SERVER
Database
Application
Communication
database
application
printing
email