ATM switching system

摘要

In the ATM switching system, an ATM speech path is divided into a plurality of functional blocks (101 - 10n, 120; 130, 110). A routing function for distributing cells (packets) each of a fixed length to address outgoing lines and a logical multiplexing function are imparted to a switch (110), while other functions associated with a line typified by a phase synchronizing function and a flow control function are incorporated en bloc in ATM line terminating units (101, 10n) and functions capable of being processed by hardware in common to the lines are assembled in a line common unit (120, 130). The ATM line terminating unit physically terminates transmission lines and performs the processing relevant to header information of the cells each of a fixed length (ATM terminating processing) and includes a cell phase synchronizing circuit (202) for matching the temporal positions of the cells among the lines and a flow control circuit (205) for avoiding overload exceeding the load declared by subscriber terminal. The line common unit serves for processings of call control signals and the calls and includes a signal processing circuit (120) and a control circuit (130). The switch performs cell multiplexing and switching and is constituted by a self-routing switch.