Practical Network Design LFTSP 1999 IS 4'2

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Practical Network DesignLFTSP 1999 IS 4.2

• Major Greg Phillips
• Royal Military College of Canada
• Electrical and Computer Engineering
• greg.phillips_at_rmc.ca
• 01-613-541-6000 ext. 6190

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Network Design Process
Assess needs and costs
Select topologies and technologies to meet needs
Model network load
Implement
Simulate behaviour under expected load
Perform sensitivity tests
Rework design as needed
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Assessing User Requirements

• Key issue for users is typically application
  availability
• Key parameters of application availability are
• response time
• throughput
• reliability

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Assessing Costs

• Equipment hardware and software costs
• Performance trade-off costs
• Installation costs
• Expansion costs
• Support costs
• Cost of downtime
• Opportunity costs
• Sunken costs

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User Equipment
Workstation (PC)
Printer
Printer (laser, colour laser, etc.)
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LAN Topologies
Ethernet logical bus physical star CSMA/CD 10
Mbps 100 Mbps
Token Ring logical ring physical star token
passing 4 Mbps, 16 Mbps 100 Mbps
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Infrastructure Equipment
Server (file, disk, mail, web, firewall,
authentication, etc.)
Server
Hub
LAN switch
ATM switch
Router
Modem
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Network Operating Systems

• Typically provide
• network level authentication
• file sharing
• print services
• mail
• directory services
• Examples
• Banyan Vines
• Novell Netware
• Microsoft NT Networking
• Internet protocols (require TCP/IP)
• NIS, NFS, lpr, SMTP/sendmail, DNS, HTTP

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Small Administrative Office
Printer
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Hub Function
approximates
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Small Engineering Office
Printer
File Server
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LAN Switch Function
File Server
approximates
File Server
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Small Office Internet Access
The Internet
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Small Office Internet Presence
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Larger Office or Campus
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The World
?
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Practical NetworkingLFTSP 1999 IS 4.2

• http//www.cisco.com/univercd/data/doc/cisintwk.ht
  m

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Bits n Pieces
Server
Hub
LAN switch
ATM switch
Router
Modem