Introduction

SS7/C7 is a signaling network and protocol that is used worldwide to bring telecommunications networks, both fixed-line and cellular, to life. Setting up phone calls, providing cellular roaming and messaging, and converged voice/data services, such as Internet Call Waiting, are only a few of the vast number of ways that SS7/C7 is used in the communications network. SS7/C7 is at the very heart of telecommunications, and as voice networks and data networks converge, SS7/C7 will provide the technology to bridge the gap between the two worlds. Anyone who is interested in telecommunications should have a solid understanding of SS7/C7. The convergence of voice and data has extended the need to understand this technology into the realm of those working with data networks.