Patent ID: 6118759
Filing Date: 2000-09-12
Classification: H04L

Abstract:
A network system comprising an ATM (Asynchronous Transfer Mode) network, plural IWFs (Inter Work Function) respectively connected to the ATM network, plural frame relay networks respectively connected to the plural IWFs, and plural terminals respectively connected to the plural frame relay networks; wherein,each of said plural frame relay networks including:addition means, when a frame is transmitted to one of the plural IWFs, for adding a quality information header in which quality information of the ATM network is stored to the frame;reading means, when a frame is received from one of the plural IWFs, for reading the quality information from the quality information header of the frame; and,memory means for memorizing the quality information read by the reading means,wherein each of the plural frame relay networks further including:reception frequency storage means for memorizing a reception frequency of frames received from one of the plural IWFs;transmission number storage means, when the frame is transmitted to one of the plural IWFs, for storing a transmission number in the quality information header of the frame; and,obtainment means, when the frame is received from one of the plural IWFs, for reading the transmisison number from the quality information header and reading the reception frequency of the frame from the reception frequency storage means, and for obtaining a difference between the transmission number and the reception frequency of the frame as a number of discarded frames in the ATM network.