Chapter 1. Introducing Voice Gateways

After reading this chapter, you should be able to perform the following tasks:

• Describe the characteristics and historical evolution of unified communications networks, the three operational modes of gateways, their functions, and the related call leg types.

• Explain how gateways route calls and which configuration elements relate to incoming and outgoing call legs.

• Describe how to connect a gateway to traditional voice circuits using analog and digital interfaces.

• Define DSPs and codecs, and explain different codec complexities and their usage.