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CHAPTER An Evolution of Physical Network Architectures. 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.
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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
Chapter Modules • Small Computer Networks • Medium Sized Computer Networks • Large Scale Computer Networks • Enterprise Computer Networks • Wide Area Networks
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
MODULE Small Computer Networks
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
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
Suns Computer Network Sun Enterprise Server Pentium Pentium
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
MODULE Medium Sized Computer Networks
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
Centralized Architecture: Medium Sized Computer Network AS 400 OS 400 Micro Micro Token Ring Micro OS2 / Warp
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
Decentralized Architecture: A Switched LAN Ethernet Switch Hub Hub Client Client Client Client Client Client Ethernet LAN Segments
MODULE Large-Scale Computer Networks
Types • Centralized Architecture • Decentralized Architecture • Combination of both
Examples • Mainframe computer • Centralized • Heterogeneous LAN • Distributed
Large Scale Centralized Computer Network Modem Server DASD Hard Disk Term. PC Front-end Processor Concentrator Mainframe Pc
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
LAN Reference Terminology for Equipment • Internetworking devices • Switches, Routers etc. • Clients or Workstations • PCs
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
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
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
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
MODULE Enterprise Computer Networks
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
Enterprise Systems Network: Centralized Architecture External Lines Mainframe Ter. Ter. Front End Processor Mini- Computer Modem Server Gateway Concentrator LAN Term. Term. PC PC
Enterprise Systems/Campus Network Bus LAN Mainframe Systems Modem Gateway Fiber Optic Backbone (FDDI) Ring LAN WAN Connection Star LAN
MODULE Wide Area Networks
Types • By virtue of its definition, it is a decentralized network
Wide Area Network Overview Terminal or Microcomputer Public Network (Frame Relay ATM, X.25) Mainframe Systems LANs Enterprise Systems Network Campus Network
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