1. Traffic Sensitive Active Queue Management
Vishal Phirke, Mark Claypool, Robert Kinicki
CS Department
Worcester Polytechnic Institute
Worcester, MA 10609, USA
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 >= 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  = 

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

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

8. Evaluation: Set 2 Delay Hint   1 0 0.917 0.083 0.834 0.166 0.75 0.25
1 0

9. 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,”
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 ftp://ftp.cs.wpi.edu/pub/techreports/02-10.ps.gz