CHAPTER An Evolution of Physical Network Architectures

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CHAPTER An Evolution of Physical Network
Architectures
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Chapter Objectives

• Discuss the different network hardware
  architectures that span varying sizes of business
  enterprises
• Provide an insight into LAN architectural
  evolution
• Centralized, decentralized, mixed etc.
• Introduce the WAN architecture that is becoming
  increasingly relevant to the Internet

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Chapter Modules

• Small Computer Networks
• Medium Sized Computer Networks
• Large Scale Computer Networks
• Enterprise Computer Networks
• Wide Area Networks

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Chapter Focus on Functional Types

• Distributed
• LAN driven
• Current trend
• Centralized
• Mini/Mainframe derived
• Past trend and probably the future trend
• Combination
• Distributed/ Centralized
• Emerging trend

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MODULE

• Small Computer Networks

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Major Types

• Distributed
• Resources and executions are distributed over the
  network
• LAN
• Centralized
• Resources and execution are confined to a central
  unit
• Multi-user Micro
• A Unix multi-user computer operating under the
  Unix operating system
• Entry-level minicomputers also known as
  departmental computers

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LAN Evolution
Past Present
Future
Application Server (Client-Server Technology)
File Server
Thin-Clients Terminal Servers
Distributed execution
Cooperative execution
Centralized execution
Mainframe architecture of the past
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IBM 9370 Virtual Machine Example
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END OF MODULE
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Suns Computer Network
Sun Enterprise Server
Pentium
Pentium
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Web Research

• Visit www.sun.com and obtain information about
  their Sun Enterprise servers
• How are they networked together?
• Choose a server to serve 25 workstations
• Sun Enterprise Server 220R

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MODULE

• Medium Sized Computer Networks

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Major Types

• Centralized architecture
• Past, present and possible future
• Minicomputers
• Decentralized architecture
• Present
• Very large LANs with Multiple segments
• Mixed architecture
• Combination of both of the above
• Large LAN with different network segments

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Centralized Architecture Medium Sized Computer
Network
AS 400
OS 400
Micro
Micro
Token Ring
Micro
OS2 / Warp
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Web Research

• Visit www.ibm.com to obtain more information
  about the configuration of an AS 400 computer
  for
• Running OS/400
• Functioning as a file server for a Windows net
  work
• Name the different IBM server families
• Visit www.search400.com for additional
  information on AS/400

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Decentralized Architecture A Switched LAN
Ethernet Switch
Hub
Hub
Client
Client
Client
Client
Client
Client
Ethernet LAN Segments
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END OF MODULE
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MODULE

• Large-Scale Computer Networks

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Types

• Centralized Architecture
• Decentralized Architecture
• Combination of both

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Examples

• Mainframe computer
• Centralized
• Heterogeneous LAN
• Distributed

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Large Scale Centralized Computer Network
Modem Server
DASD
Hard Disk
Term.
PC
Front-end Processor
Concentrator
Mainframe
Pc
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Mainframe Reference Terminology for Equipment

• DCE (Data Communication Equipment)
• Front-end Processor, Modem Server and
  Concentrator for example
• DTE (Data Terminal Equipment)
• Terminals, PCs and Printers for example

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LAN Reference Terminology for Equipment

• Internetworking devices
• Switches, Routers etc.
• Clients or Workstations
• PCs

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Heterogeneous LAN Architecture
LANs With Servers/Minicomputers
Router
Switch
Server 1
Hub
Server 2
WS
Hub
WS
WS
WS
WS
WS
WS
WS
WS
Server 4
Server 3
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Switch

• Switch network traffic between the LAN segments
• Allows crossover traffic from one segment to
  another segment
• Otherwise, the network traffic is confined to the
  individual segments
• Used for connecting LAN segments that operate
  under the same protocol
• Performs Layer 2 functions
• Newer switches may also perform some routing
  which is a Layer 3 functions
• Such switches are called Layer 3 switches

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Router

• Used for connecting LAN segments that operate
  under different protocols
• A more advanced device compared to the switch
• Routes traffic between different LANs
• Performs Layer 3 functions

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Web Research

• Visit www.whatis.com and get the definition for
  switches and gateways
• Access www.cisco.com to obtain further
  information on the following
• Switch
• Router

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END OF MODULE
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MODULE

• Enterprise Computer Networks

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Major Types

• Centralized
• Based on mainframes
• Mainframe derived architecture
• Decentralized
• Based on a backbone used of connecting LANs and
  other computer systems
• LAN driven architecture

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Enterprise Systems Network Centralized
Architecture
External Lines
Mainframe
Ter.
Ter.
Front End Processor
Mini- Computer
Modem Server
Gateway
Concentrator
LAN
Term.
Term.
PC
PC
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Enterprise Systems/Campus Network
Bus LAN
Mainframe Systems
Modem Gateway
Fiber Optic Backbone (FDDI)
Ring LAN
WAN Connection
Star LAN
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END OF MODULE
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MODULE

• Wide Area Networks

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Types

• By virtue of its definition, it is a
  decentralized network

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Wide Area Network Overview
Terminal or Microcomputer
Public Network (Frame Relay ATM, X.25)
Mainframe Systems
LANs
Enterprise Systems Network
Campus Network
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Web Research

• Access a reference website such as www.whatis.com
  to obtain information on the following
• ATM, Frame Relay, X.25
• DS1, DS3 etc.
• T1, T3 etc.
• OC1, OC3 etc.
• Switches and Routers

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END OF MODULE
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END OF MODULE END OF CHAPTER