Capacity management's goal is to ensure that information technology resources are sufficient to meet upcoming business requirements cost-effectively. One common interpretation of capacity management is described in the ITIL framework. ITIL version 3 views capacity management as comprising three sub-processes: business capacity management, service capacity management, and component capacity management. As the usage of IT services change and functionality evolves, the amount of central processing units (CPUs), memory and storage to a physical or virtual server etc. also changes. If there are spikes in, for example, processing power at a particular time of the day, it proposes analyzing what is happening at that time and making changes to maximize the existing IT infrastructure; for example, tuning the application, or moving a batch cycle to a quieter period. This capacity planning identifies any potential capacity related issues likely to arise, and justifies any necessary investment decisions - for example, the server requirements to accommodate future IT resource demand, or a data center consolidation. These activities are intended to optimize performance and efficiency, and to plan for and justify financial investments. Capacity management is concerned with: Monitoring the performance and throughput or load on a server, server farm, or property Performance analysis of measurement data, including analysis of the impact of new releases on capacity Performance tuning of activities to ensure the most efficient use of existing infrastructure Understanding the demands on the service and future plans for workload growth (or shrinkage) Influences on demand for computing resources Capacity planning of storage, computer hardware, software and connection infrastructure resources required over some future period of time. Capacity management interacts with the discipline of Performance Engineering, both during the requirements and design activities of building a system, and when using performance monitoring. Factors affecting network performance Not all networks are the same. As data is broken into component parts (often known frames, packets, or segments) for transmission, several factors can affect their delivery. Delay: It can take a long time for a packet to be delivered across intervening networks. In reliable protocols where a receiver acknowledges delivery of each chunk of data, it is possible to measure this as round-trip time. Jitter: This is the variability of delay. Low jitter is desirable, as it ensures a steady stream of packets being delivered. If this varies above 200ms, buffers may get starved and not have data to process. Reception Order: Some real-time protocols like