Network design

Topic 6Testing and documentation

Agenda

• 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

• 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– 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– 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

• 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

– 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• 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

• Testing tasks• Prototyping• Testing plan• Tools • Network design document