Traffic Sensitive Active Queue Management Vishal Phirke, Mark Claypool, Robert Kinicki CS Department Worcester Polytechnic Institute Worcester, MA 10609, USA http://perform.wpi.edu/ ftp://ftp.cs.wpi.edu/pub/techreports/02-10.ps.gz

AQM Support for QoS RED-Boston Delay Hint Moving Target Weighted Insert

Using Delay Hints – An Example T1 link H.261 Videoconference

A Moving Target

The RED-Boston Algorithm On receiving packet pkt: target = AdjustTarget(target, pkt.delay) if (qavg >= maxth) then dropPacket(pkt, 1) elseif (qavg >= minth) then p = calcDropP(qavg , minth, maxth, maxp) p’ = p  (delayavg/pkt.delay) if (!dropPacket(pkt,p’)) then weight = arrival_time + pkt.delay insertPacket(pkt, weight) Every interval seconds: if (qavg > target) then maxp +=  elseif (qavg < target) then maxp  = 

Evaluation QoS = T / D  Set 1 Set 2 T is Throughput D is Delay  +  = 1

Evaluation: Set 1 Normalized QoS Throughput (QoS = T 1/D 0) Sensitive Delay

Evaluation: Set 2 Delay Hint   1 0 0.917 0.083 0.834 0.166 0.75 0.25 1 0 0.917 0.083 0.834 0.166 0.75 0.25 0.67 0.33 0.584 0.416 16 0.5 0.5

RED-Boston Summary Select References Per-Flow QoS driven by Application Scalable (No per-flow state required) No monitoring, policing or shaping required Compatible within DiffServ class or with current Best-Effort Internet Select References S. Floyd, R. Gummandi, S. Shenker. “Adapative RED,” http://www.icir.org/floyd/papers/adaptiveRed.pdf, 2001. P. Hurley, M. Kara, J.L. Boudec, P. Thiran. “ABE: Providing Low Delay within Best Effort,” IEEE Network Magazine, May/June 2001. Vishal Phirke, Mark Claypool, Robert Kinicki. “Traffic Sensitive Active Queue Management,” Technical Report WPI-CS-TR-02-10, CS Department, WPI, May 2002. ftp://ftp.cs.wpi.edu/pub/techreports/02-10.ps.gz