ATM EXCHANGE

摘要

PROBLEM TO BE SOLVED: To solve a problem that so-called impartial distribution cannot be warranted because of different transmission rates due to difference from input side cell buffers through which cells pass even between ABR connections of the cells passing through a same ATM exchange in an input output buffer type ATM exchange where buffers are placed before and after a switch port in the inside of the ATM exchange. SOLUTION: A congestion state of input side cell buffers is written in an idle field of a backward resource management RM cell as a logic queue length or an explicit rate ER value calculated from the logic queue length and the resulting cell is transferred to an ATM switch section. The ATM switch extracts and collects a state of the input cell buffers to decide the ER value according to a congestion state of the entire witch and calculates the ER value from the logic queue length of output buffers for each output channel to warrant impartial distribution of the band for all input and output channels of the ATM switch.