Telecom : Network Control

Network control is the transmission of signals or messages that perform call control, equipment configuration, or information management functions. Network control can be centralized or distributed. The control of public telecommunications networks is a centralized system as call processing is coordinated through a controlled common channel signaling (CCS) network. The Internet uses distributed control as the switching information dynamically changes in packet switching centers (routers) throughout the Internet network.

Common Channel Signaling (CCS)
Common channel signaling system #7 (“SS7”) is the primary system used for interconnection of telephone systems. SS7 sends packets of control information between switching systems. Figure below shows the basic structure of the SS7 control signaling system. The SS7 network is composed of its own data packet switches, and these switching facilities are called signal transfer points (STPs). In some cases, when advanced intelligent network services are provided, STPs may communicate with signal control points (SCPs) to process advanced telephone services. STPs are the telephone network switching point that route control messages to other switching points. SCPs are databases that allow messages to be processed as they pass through the network (such as calling card information or call forwarding information).


SS7 Common Channel Signaling

Because the public telephone network uses common channel signaling, intelligence in the network can be distributed to databases and information processing points throughout the network. A set of service development tools has been developed to allow companies to offer advanced intelligent network (AIN) services.