Traffic Sensitive Active Queue Management

1
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

2
AQM Support for QoS

• RED-Boston
• Delay Hint
• Moving Target
• Weighted Insert

3
Using Delay Hints An Example

• T1 link
• H.261 Videoconference

4
A Moving Target
5
The RED-Boston Algorithm

• On receiving packet pkt
• target AdjustTarget(target, pkt.delay)
• if (qavg gt maxth) then
• dropPacket(pkt, 1)
• elseif (qavg gt 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 gt target) then
• maxp ?
• elseif (qavg lt target) then
• maxp ? ?

6
Evaluation
Set 1
Set 2
QoS T ?/ D ? T is Throughput D is Delay ? ?
1
7
Evaluation Set 1
Throughput Sensitive
Normalized QoS (QoS T 1/D 0)
Delay Sensitive
Normalized QoS (QoS T 0.5/D 0.5)
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Evaluation Set 2

• Delay Hint ? ?
• 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

9
RED-Boston Summary

• 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/techreport
  s/02-10.ps.gz