Fuente: Wipo "digitalization" ABSTRACT A telephone switching system for telephone lines in a telephone network that carry voice and associated super- visory information signals. The voice signals are received through one of a plurality of ports under the control of a port event processor and are transferred through a switching arrangement, under the control of a call pro- cessor, and transmitted through a port again under the control of the port event processor. The received super- visory information is stored in a port data store memory, which also stores call state and command information. The port event processor retrieves the stored supervisory information and commands from the port data store memory, and processes the supervisory information in response to the commands in at least two functional units, and returns processed information for storage in the port data store memory.