1. Computer Science 1 Providing QoS through Active Domain Management Liang Guo, Ibrahim Matta Quality-of-Service Networking Lab CS Department Boston University

2. Computer Science 2 System Overview

3. Computer Science 3 Case Study: Fairness Issues  Motivation:  Most TCP flows are short  Short flows are vulnerable to packet losses  Short flows are less responsible to congestion control  Proposal:  Giving high priority to short flows  Approach: Differentiated Services Architecture  Goal: a fair,predictable network

4. Computer Science 4 Simulation Setup  Web Traffic as background  Monitor transmission time of 10 Short + 10 Long flows Web Servers Traffic Controller RIO-PS queue Clients avg short avg total Short flow Long flow

5. Computer Science 5 Simulation Results: Fairness Index

6. Computer Science 6 Simulation Results: Transmission Time Short FlowsLong Flows  New scheme produces less “outliers”

7. Computer Science 7 Experimental Setup

8. Computer Science 8 Future Work  Performance Evaluation of Differentiated Services  Fairness-oriented Active Domain Management  Real-time Scheduling  Traffic Controller Design  Other Layer-7 Switching Techniques FOR MORE INFO... Quality-of-Service Networking Laboratory Computer Science Dept., Boston University Copyright 2001