CONGESTION CONTROL SYSTEM FOR ATM NETWORK

摘要

PROBLEM TO BE SOLVED: To operate the network efficiently by allowing a receiver side to easily confirm occurrence of an aborted packet due to congestion of the network. SOLUTION: An input cell of an asynchronous transfer mode adaptation layer AAL-type 5 is received from an input terminal A and written in a cell buffer 106 via a selector 104. A final cell extract circuit 102 detects a final cell of the AAL type 5 with VCI=N from the received cell 1 and provides an output of a final cell selection signal 4 with respect to the final cell only with VCI=N. A VCI extract circuit 101 extracts the VCI from the input cell 1 and provides an output of a VCI selection signal 3 with respect to a cell with VCI=N only. A congestion cell generating circuit 103 generates a congestion cell 5 in a timing of the final cell selection signal 4. A congestion cell insert control circuit 105 outputs a congestion cell insert selection signal 10 when a buffer threshold level exceed signal 6 in a timing of the final cell selection signal 4 to throw the input of the selector 104 to a position D so as to select a congestion cell 5 as a cell buffer write cell 2.