Publisher Summary This chapter focuses on network architecture, and describes what is contained within the architecture of a network and how to develop this architecture. It discusses the concept of relationships within and among components of the architecture. The component approach to network architecture defines the building blocks of architecture as network functions. By weighting the interactions among components, the network architecture can be tailored to meet the specific needs of a network. The chapter emphasizes on the factors that make up these relationships and how they apply to each architectural component. Component architectures and the resulting reference architecture can be further refined and validated through network modeling and simulation. This supports a logical progression through the architectural process. Implementation of the process reveals numerous interactions among component architectures. Several architectural models are presented to use as a starting point in developing the network architecture. Many terms for addressing and routing, performance, network management, and security are presented.