Measurement of ATM Frame Latency

This paper addresses the problem of measuring frame latency in ATM switches. The frames consisting of several ATM cells may arrive with numerous gaps between cells. It is important that the gaps present in the input stream be not counted towards the switch's contribution to the frame delay. The proposed solution called "MIMO" (Message-In Message-Out) latency improves upon other latency metrics commonly used for continuous frame technologies such as frame relay. MIMO latency is defined as the difference between LILO latency through the switch and that through an ideal switch. The definition and the discussion also apply to any network of switches as well. We show that the formulation of MIMO aggregation is very useful in understanding the contribution of each network element and their interconnections in the total frame latency.