Abstract: A system and data transfer method capable of reducing the influence of data transfer upon processing of the software is disclosed. Access to the memory by each of the processor and the communication interfaces is managed by a scheduler. When storing data received from a communication interface into the memory, a message converter receives a reception completion message from the communication interface and converts it to a transmission request message when determining that the data having stored in the memory is data to be sent to another communication interface. When receiving the transmission request message, the other communication interface reads the data from the memory.

Abstract: The server device comprises a database for storing identification information for identifying the client in correspondence with an individual password assigned to the client, obtaining means for obtaining the telephone number information of the client transmitted via the communications line, and retrieving means for retrieving the identification information from the database based on the telephone number information obtained by the obtaining means. And when the telephone number information is authenticated as the information of the client according to the identification information retrieved by retrieving means, an image for returning the password is transmitted with respect to the client. And in the event the password returned from the client matches the password stored in the database, the services are provided from the server device to the client.

Abstract: In a protection switching system for N working transmission systems and a spare transmission system, first to Nth protection switches (11-1.about.11-n) am provided corresponding respectively to the N working transmission systems (21-1.about.21-n). Each protection switch includes a forward/backward impedance matching circuit (30, 31) and first, second and third pairs of terminals (c, d; h, i; g, j), the first pair terminals (c, b) of each protection switch (11) being connected to the corresponding working transmission system. The second pair terminals (h, i) of each of the first to (N-1)th protection switches are connected respectively to the third pair terminals (g, J) of the second to Nth protection switches, the second pair terminals (h, 1) of the first protection switch being connected to the spare transmission system (20), and the third Fair terminals (g, j) of the Nth protection switch being connected together.