An ATM Interface with Facilities for Traffic Generation and Monitoring

This paper describes an ATM interface with additional facilities to also allow it to act as both a traffic monitor and traffic source. High resolution timing is provided to enable all received cells to be time stamped on arrival and the information passed back to the user. For transmission, a cell has an associated target transmission time and the transmit hardware will block the head of the transmit queue until the target transmit time is reached. This interface is intended to serve two purposes: as a conventional interface for ATM based projects and also as a piece of test equipment to act as a traffic source or monitor (or both) for use in experiments on ATM network performance. As a conventional interface, the control over transmit time for individual cells gives facilities for implementation of traffic shaping schemes. As a piece of test equipment, the control over precise transmit times and the recording of cell receive times allow accurate measurements to be made on network performance which would not be possible with a conventional interface.