The principles, guidelines, and procedures for requirements analysis are all part of the process model. This model, shown in Figure 3.1, outlines the major steps to gather, analyze, and develop requirements for your network.
Figure 3.1: Requirements analysis process.
In this chapter you will learn about gathering and managing user, application, device, and network requirements. This includes setting and managing your customer's expectations about the network. You will learn about determining which variables to measure (service metrics) and how to make measurements. We will introduce modeling and simulation and discuss how they and other approximation techniques can be used to describe user and application behavior. You will learn about developing performance requirements for capacity; delay; and reliability, maintainability, and availability (RMA), including developing performance thresholds and limits. These will be useful in distinguishing between low-and high-performance requirements for your network. You will learn about general and environment-specific thresholds and limits and how to determine them. Some general thresholds are presented for your use. We will also discuss predictable and guaranteed performance requirements and their importance. Along with gathering and developing requirements, you will also learn about mapping requirements to geographic locations in preparation for traffic flow analysis.