Abstract: A switching system for application services is provided with a terminal. At least one application processor stores a plurality of application programs for providing a plurality of the application services. Switching equipment couples the terminal to the application processor. The terminal has a specifying means for specifying one arbitrary application service out of the plurality of application services. When a user specifies the one arbitrary application service using the specifying means of the terminal, this information is transmitted to a common control unit of the switching equipment. The common control unit receives the application service specifying information from the terminal, and transfers this application specifying information to the application processor. The application processor selects the one arbitrary application service based on the application service specifying information which is transferred from the switching equipment.

Abstract: A loop transmission system and a method of controlling the loop-back condition thereof. The loop transmission system comprises a plurality of node stations, a supervisory station, and two duplicate loop transmission lines which transmit signals in opposite directions. In the loop transmission system, the supervisory station first sends out loop-back commands via both of the duplicate loop transmission lines when faults are detected on both of the duplicate loop transmission lines at the same time. Each of the node stations establishes a loop-back path while retaining a connection path to a succeeding node station upon the receipt of a loop-back command. The loop-back path is released only in the node stations which receive signals normally from both of the duplicate loop transmission lines when the supervisory station sends release commands to the node stations after sending the loopback commands.