Abstract: A method for monitoring and controlling traffic in real time at an asynchronous transfer mode (ATM) switching node, comprising the steps of retrieving the virtual path identifier (VPI)/virtual channel identifier (VCI) field and cell loss priority (CLP) field from the header of a received ATM cell to determine the validity of the cell by checking the effective value of the header for VPI/VCI field, comparing cell monitoring counter value (Cm) with cell control counter value (Cc) to detect violation of traffic parameter when the cell is determined to be valid, determining whether the present user's connection violates the negotiated parameter by means of traffic control data (Active_Idle) and CLP when the cell violates the traffic parameter, holding, tagging and discarding the cell according as the cell violates the negotiated parameter, transferring the result of controlling the valid cell to the physical layer to process the cell, and reporting the cell monitoring counter value to a control panel of uppe