{"title":"Scheduling latency-critical traffic: a measurement study of DRR+ and DRR++","authors":"C. Zhang, M. MacGregor","doi":"10.1109/HPSR.2002.1024247","DOIUrl":null,"url":null,"abstract":"Efficient fair queuing using deficit round-robin, DRR, proposed by Shreedhar and Varghese (1996) is a low-complexity packet scheduler that has several commercial implementations. DRR has also been extended as DRR+ to accommodate latency-critical flows. DRR+, however, assumes that a latency-critical flow exhibits very smooth arrivals whereas most network flows are very bursty in nature, either as the result of source bursts, or as a result of the dynamics of multihop network paths. When DRR+ encounters a burst, it reverts back to the behavior of DRR, providing no preference or latency bound for latency critical traffic. This is a fatal flaw that prevents DRR+ from being useful in scheduling bursty latency-critical flows. We present a different extension to DRR that has much lower delay and delay jitter than DRR+ and is capable of handling bursty latency-critical flows.","PeriodicalId":180090,"journal":{"name":"Workshop on High Performance Switching and Routing, Merging Optical and IP Technologie","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2002-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"6","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Workshop on High Performance Switching and Routing, Merging Optical and IP Technologie","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1109/HPSR.2002.1024247","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 6
Abstract
Efficient fair queuing using deficit round-robin, DRR, proposed by Shreedhar and Varghese (1996) is a low-complexity packet scheduler that has several commercial implementations. DRR has also been extended as DRR+ to accommodate latency-critical flows. DRR+, however, assumes that a latency-critical flow exhibits very smooth arrivals whereas most network flows are very bursty in nature, either as the result of source bursts, or as a result of the dynamics of multihop network paths. When DRR+ encounters a burst, it reverts back to the behavior of DRR, providing no preference or latency bound for latency critical traffic. This is a fatal flaw that prevents DRR+ from being useful in scheduling bursty latency-critical flows. We present a different extension to DRR that has much lower delay and delay jitter than DRR+ and is capable of handling bursty latency-critical flows.