Performance Measurement and Management IACT 418 IACT 918 Corporate Network Planning

Overview The performance of information technology is increasing rapidly and the need for transporting large amounts of data through a modern organisation is increasing with it Network managers are faced with the requirement to: Increase bandwidth to allow today's communications needs to be met, and allow for growth in those needs and Keep the costs down to a minimum

Overview This requires an engineering trade-off, which has to be made repeatedly So that we are not completely swamped with the size of the job, we have devised a procedure, which allows us to cope with it

Performance Management "... is a set of activities required to continuously evaluate the principal performance indicators of network operation, to verify how service levels are maintained, to identify actual and potential bottlenecks and to establish and report on trends for management decision making and planning.“ Terplan P 367

Performance Management The performance indicators are measured by the system Typical indicators are Availability Response time Throughput Utilisation Transmission volumes Errors etc

Performance Management Procedure The procedure is iterative, but we may identify four steps. Determining and quantifying current workload Projecting future workload Developing the network capacity plan Implementation

Determining and Quantifying Current Workload The information for this phase will be gathered by the network instrumentation The most important indicators of current workload are Volume of traffic Response time Lost messages Packets Utilisation Queueing theory (as a tool)

Determining and Quantifying Current Workload The number of trouble tickets will highlight areas where there are problems with reliability This information is needed for all elements in the region under consideration

Determining and Quantifying Current Workload We need to know (if we can) the breakdown of traffic between the main software applications This will become important if we intend to install new software which is expected to double the traffic of an existing, similar, application There will always be an overhead which cannot be allocated to any application in particular

Determining and Quantifying Current Workload All practical networks go through busy periods during a normal day Many networks have days of the week which are busier than others and seasonal periods such as the lead-up to Christmas The network needs to be designed to cope with the busiest times. So much of the important data will be the data for "busy hour"

Determining and Quantifying Current Workload Sometimes network connections are setup before Christmas and torn down after Christmas because of the extra traffic encountered at this time is so large as to make this an economic alternative (usually telecommunications carriers don’t like doing this but it happens)

Projecting Future Workload This depends on our ability to talk to others in the organisation The company's business plan may include buying a powerful new software package which will increase the load by 70% between some parts of the network Or it may be that we are about to increase our web usage because we are moving into e-commerce

Projecting Future Workload Other effects that change the amount of traffic on the network would be: Increasing sales Increasing personnel and payroll Opening or closing remote locations New operating systems

Projecting Future Workload It may be that some areas are more sensitive than others for the success of the overall business Most companies dealing with the public or a large number of customers would require that inquiries from potential customers received the best possible reception Companies dealing with a few large customers would already have well established relationships

Projecting Future Workload It has also been observed that the improved performance or attractiveness of a new application results in more traffic being generated, just because workers like it better As we look further into the future it becomes more and more difficult to predict what the demand will be This might lead us to plan for only a year in advance. But, if a little extra expense would give us a large increase in performance, we may be justified in taking a little extra risk

Developing the Network Capacity Plan We start with a knowledge of the present network and its traffic loads etc, and our prediction of the future demands of the organisation We will develop the network capacity plan in three steps, facilities, equipment and evaluation More in next weeks lecture

Response Management Response time at the customer level is a very important issue We need to break the response time up into at least Networking delay System response time Output response time Then we can see where the greatest scope for improvement lies