Summary
This chapter has shown that, although it is transparent, SS7/C7 plays a role in the lives of virtually every individual in developed countries. It is also the key to new, revenue-generating services and is crucial to the QoS as perceived by subscribersboth of which lie at the very heart of success in a fiercely competitive telecommunications market. Furthermore SS7/C7 is a common thread that ties fixed-line, cellular, and IP networks together, and it is a key enabler for the convergence of the telecommunications and data communications industries.