Network design
Topic 6
Testing and documentation
Agenda
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Testing tasks
Prototyping
Testing plan
Tools
Network Design Document
Testing
• Ensure that the design has met the business and
technical goals
• Provide assurance and demonstrate to the
customer that the solution meets business and
technical goals
• Identify problems
• Acceptance testing
– To demonstrate how the solution meets the goals to
the customer's satisfaction
– To obtain signoff and approval to move to
implementation stage
Testing tasks
• Verify that the design meets business and
technical goals
• Validate LAN and WAN technology and device
selections
• Verify the Service Provider plan
• Identify bottlenecks or connectivity problems
• Test redundancy and effect of link failure
• Determine optimisations
• Acceptance testing
• Identifying risks and planning for the
implementation process
Industry testing
• Vendors, independent test labs and trade
journals publish testing information
• Generally, most tests are component tests and
not whole system tests
– Testing results made not be relevant to the design
and configuration
– How valid are the test results?
• For complex networks, design your own tests
Prototyping
• Prototype is a model of a system which can
validate the operation and performance of the
system
– It is not the complete system
– Should include the most important functions and
risky functions
– Should demonstrate elements of the design to the
customer
– Use resources effectively: people, equipment,
money and time
Prototyping
• Test network in a lab
– Work out the bugs without impacting users
– Initial configurations, evaluate products
– Model predicted performance and QoS
• Integrated into production network but tested
off hours
• Integrated into a production network and
tested in business hours
Planning a ‘live’ test
• Advise users in advance and ask them to
continue with normal work tasks
• Advise administrators and managers in
advance
• Run multiple short tests to minimise user
impact
• Run tests with small traffic and configuration
changes first and move up to larger impact
tests
Test plan
• Test objectives and acceptance criteria
• Types of test to run
• Network equipment and other resources
required
• Test scripts
• Timeline and milestones for testing the
project
Objectives and acceptance criteria
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Based on the business and technical goals
Objectives should be specific and concrete
Stated so that a pass or fail can be recorded
Test should measure results without industry
bias and be based on industry standards
where possible
• Use baselines as reference point for
comparison tests, eg 20% less CRC error rate
Types of test to run
• Performance tests
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Throughput
Delay
Delay variation
Response time
Efficiency
• Stress tests
– Decreased service when the load increases
• Failure analysis
– Network availability and accuracy
– Causes of outages
• Other tests
– Manageability, useability, adaptability, security, regression
Documenting network equipment
• Network topology drawing
– Major devices, addresses, names, WAN and LAN links and link
capacity
• List of devices that will be required
– Names, version numbers, availability
• Testing tools
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Network management and monitoring tools
Traffic generation tools
Modelling and simulation tools
QoS and service-level management tools
• Other resources needed
– Time in lab
– Power, air conditioning, rack space
– Staff and users required
Test scripts
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Test objective
Acceptance criteria
Topology
Testing steps
– What tools is used for each step
– What measurements will be taken
– Initial values and testing parameters
– What information will be logged
Timeline and milestones
• List major tasks and the person assigned to those tasks
– Writing test objectives and acceptance criteria
– Design the network topology
– Determine hardware and software
• Order hardware and software
• Confirm availability
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Write test scripts
Install and configure hardware and software
Conduct tests
Log results
Analyse results
• Create test report
– Present results to customer
Testing tools
• Network-management and monitoring tools
– Cisco Works
– HP OpenView
– IOS commands and OS tools
• Traffic-generation tools
– Protocol analyser
– Multiport traffic generators
• Modelling and simulation tools
• QoS and service-level-management tools
– NetPredictor
Network design document
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Executive summary
Project goal
Project scope
Design requirements
– Business goals
– Technical goals
– User communities and data
stores
– Network applications
• Current state of the network
– High level map
– Health and performance
analysis
• Logical design
• Physical design
• Results of network design testing
• Implementation plan
– Project schedule
– Project budget
• Design document appendix
Agenda
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Testing tasks
Prototyping
Testing plan
Tools
Network design document