Latency (engineering)

About: Latency (engineering) is a research topic. Over the lifetime, 7278 publications have been published within this topic receiving 115409 citations. The topic is also known as: lag.

The effects of latency on online madden NFL football

Abstract: With growth in interactive network games comes increased importance in a better understanding of the effects of latency on game performance. While previous work has measured the effects of latency on first-person shooters and real-time strategy games, there has been no systematic investigation of the effects of latency on sports games. In this work, we study the effects of latency on online Madden NFL football, one of the most popular online sports games, through a series of carefully designed experiments in which we systematically control latency between players. Our experiments illustrate the mechanisms Madden NFL uses to compensate for latency. Our user studies show there is little impact from latency on user performance in Madden NFL over typical low Internet latencies. However, for latencies higher than 500 ms, there is a significant impact on user performance, degrading performance by almost 30%. Our network measurements show periodic data rates during game-play with significant command aggregation at higher latencies.

Dynamic latency-based rerouting

Abstract: A switch creates and dynamically updates a latency map of a network to adjust routing of flows. Further, the network is monitored to detect latency issues and trigger a dynamic adjustment of routing based on the latency map. In this manner, a flow can be routed along a route (i.e., a faster route) that provides less latency than other available routes. The latency map can be generated based on latency probe packets that are issued from and returned to the source switch. By evaluating many such latent probe packets that have traveled along many available routes (e.g., corresponding to various ports of the switch), the switch or associated administrative logic can dynamically adjust the latency map to updated latency information of available routes. Therefore, responsive to a trigger, the source switch can dynamically adjust the routing of a flow based on latency issues discerned from the network.

Cost calculation in load balancing switch protocols

Abstract: A method for computing cost information associated with a port of a switch in a network of switches. Cost information is computed as a port load factor: a ratio of port latency over available throughput. Port latency is determined as the depth of a queue associated with the port divided by the speed of the port. Available throughput is determined as the speed of the slowest port on a given path associated with the port in question. Preferably, the queue depth is measured in bits and the port speed and available throughput are measured in bits per second. Further, in the preferred embodiment, port latency is computed as a weighted average as ((15×previous latency)+current latency)/16. A higher value for the port load factor indicates a port which is more heavily loaded. The load factor is therefore useful in load balancing among the ports of switches and paths associated therewith.