The attached nam file (adc.nam) shows a simple comparison between a comparison between measurement-based admission control and parameter-based admission control. The measurement-based algorithm is the Measured Sum algorithm given in "Comparison of Measurement-Based Admission Control Algorithms for Controlled-Load Service", by Jamin, Shenker and Danzig in Infocomm '97. The parameter-based algorithm makes admission control decisions based on reserved rates. In the animation, there are two bottleneck links with capacity 1Mbps. Link 6-7 uses the parameter-based algorithm, and Link 0-1 uses the measurement based algorithm. The remaining links in the topology have 5Mbps capacity and are never congested. The key point to notice is that when presented with equal average offered load (in terms of the number of flows requesting reservations) the measurement-based algorithm, which makes admission decisions based on the token bucket parameters of the flow requesting service and on the measurements of traffic sent by flows with existing reservations, admits more flows and achieves a higher measured utilization on the bottleneck link than the parameter-based algorithm, which makes admission decisions using the token bucket parameters of the new flow and the reserved rate of existing flows. The 3 magenta nodes on the left are the sources of traffic and the 3 orange nodes on the right are destinations. Flows are started randomly between pairs of source and destination nodes. When a flow is started, a reservation request (white packets in the animation) is sent from the source (Node 8, 2 or 3) to the destination (Node 9, 5 or 4). The token bucket parameters in the reservation packet are r = 64kbps are b = 1. Admission control decisions are made at either node 0 or node 6. Based on the admission control decision, the destination returns either an Accept packet (green) or Reject packet (red) to the source. A source that receives an Accept then transmits data (the data packets are not shown in the animation). After sending its data, the source transmits a Teardown packet (black) to signal the network it no longer needs its reservation. The bottleneck links change color to reflect the last admission control decision made on the link. When reservation requests are accepted, the link turns (or remains) green. When a reservation request is rejected, the link turns (or remains) red. Monitors associated with the admission control agents at Nodes 0 and 6 display relevant information about the state of the admission control process and link utilization. Each monitor shows the number of flows with reservations in place on the adjacent link, and the measured utilization on the adjacent link (utilization measures are averaged over 2 second intervals). For the parameter-based admission control algorithm, the total amount of reserved bandwidth is shown. For the measurement-based algorithm, the estimated link utilization, which is an input parameter to the decision process, is shown. (See the above-reference paper for an explanation of how this estimate is computed and used.) Other relevant parameters to the simulation that created this animation: Flow inter-arrival times are exponentially distributed with average of 400 ms on each link. Average flow lifetime is 30 seconds (again exponentially distributed). Flows transmit data according to the Exponential On/Off source model in the ns-2 simulator. Relevant parameters are: packet size = 125 bytes, on time = 312.5 msec, off time = 325 msec, and rate = 64 kbps.