Abstract: A large-scale fault tolerant asynchronous transfer mode (ATM) switch and a self-routing method in a 2n×n multiplexing switch.

Abstract: A 2n×n multiplexing switch has 2n VD(valid) extractors for validating the routing tags of the inputted cells and determine if the cell is to be saved or not, and generate VD signals, a FIFO buffer selector for selecting the FIFO buffer to store each cell using the VD signal and for transferring the cell to the selected FIFO buffer, a shared FIFO buffer consisting of 2n shared FIFO buffers and storing cells, an output device for reading cells stored in the FIFO buffers and for transferring n cells to output ports and a cell counter for counting cells currently stored in the shared FIFO buffer using the data from the FIFO buffer selector and the output device.

Abstract: A method and apparatus for making assignment of virtual path and virtual channel identifiers under a "free status" in an asynchronous transfer mode switching system, at high speed, without delaying a call processing speed of a call processing circuit. The method for assigning virtual path and virtual channel identifiers placed in a cell header area includes the step for setting predetermined header values in a memory having a FIFO function; the step for checking a storage state of the memory when a connection requirement of a call occurs; the step for transferring stored header values to interface circuits corresponding to the connection requirement after the stored header values are read from the memory when the memory is not in an empty state; and the step for storing in the memory the header values used for the call required for a release when a releasing requirement of a call occurs.