1. September 21, 2001 1 Broadband Wireless Network Applications and Performance Carey Williamson Professor/iCORE Senior Research Fellow Department of Computer Science University of Calgary

2. September 21, 2001 2 Background Information r Education: m B.Sc.(Hon.), Computer Science, U.Sask., 1985 m Ph.D., Computer Science, Stanford U., 1992 r Experience: m Dept of Computer Science, U.Sask., 1991-2001 m Adjunct Scientist, TRLabs Saskatoon, 1991-2001 r Research Areas: m Computer Networks, Performance Evaluation r Professional Service/Memberships: m ACM (SIGMETRICS, SIGCOMM), IEEE, SCS

3. September 21, 2001 3 Internet Protocol Stack r Application: supporting network applications and end-user services m FTP, SMTP, HTTP, DNS, NTP r Transport: end to end data transfer m TCP, UDP r Network: routing of datagrams from source to destination m IPv4, IPv6, BGP, RIP, routing protocols r Data Link: hop by hop frames, channel access, flow/error control m PPP, Ethernet, IEEE 802.11b r Physical: raw transmission of bits Application Transport Network Data Link Physical 001101011...

4. September 21, 2001 4 Research Interests r Network Traffic Measurement r Workload Characterization r Traffic Modeling r Network Simulation r Web Performance r Adaptive Network Applications

5. September 21, 2001 5 Network Traffic Measurement r Collect and analyze packet-level traces from a live network

6. September 21, 2001 6 Network Traffic Measurement r Collect and analyze packet-level traces from a live network, using special equipment

7. September 21, 2001 7 Network Traffic Measurement r Collect and analyze packet-level traces from a live network, using special equipment 101101

8. September 21, 2001 8 Network Traffic Measurement r Collect and analyze packet-level traces from a live network, using special equipment r Process traces, statistical analysis r Diagnose performance problems (network, protocol, application) 101101

9. September 21, 2001 9 Workload Characterization r Try to understand the salient features of network, protocol, application, and user behaviour on the Internet r Example: Web server workloads [Arlitt96] m Zipf-like document referencing behaviour m Lots of “one-time” referencing of documents m Heavy-tailed file size distributions m Self-similar network traffic profile

10. September 21, 2001 10 Traffic Modeling r Construct programs and statistical models that capture the empirically-observed network traffic behaviours r Allows flexible, controlled, repeatable generation of workloads for experiments r Examples: m Web client workload model m MPEG compressed video model m Self-similar Ethernet LAN traffic model m Synthetic Web proxy workload generator

11. September 21, 2001 11 Network Simulation r Use computer simulation to study the packet-level behaviour of the Internet, its protocols, its applications, and its users r Examples: m Improving Web performance over ADSL m Understanding the effects of user mobility on Mobile IP routing and protocol performance m Studying the design, scalability, and performance of Web server and Web proxy caching architectures

12. September 21, 2001 12 Web Performance r Explore techniques to improve the performance and scalability of the Web r Examples: m Clustered Web servers m Load balancing policies m Web prefetching strategies m Web proxy caching architectures m Improvements to HTTP and TCP protocols

13. September 21, 2001 13 Adaptive Network Applications r Explore design of Internet-based network applications (or protocols) that can adapt their behaviour (automatically) to make appropriate use of available resources r Examples: m Web content for Java-enabled phones m Multicast support for mobile users m Location-aware routing optimizations m Wireless-aware TCP protocol m File system support for mobile users

14. September 21, 2001 14 Summary of Research Plan r Broadband Wireless Networks Lab (UofC) r Experimental Laboratory for Internet Systems and Applications (UofS/UofC,CFI) r Research Team: m Four full-time research staff (Web, perf. eval., simulation, wireless, traffic modeling, network measurement) plus 6-10 graduate students r Research Collaborations: m UofC, UofA, UofS, TRLabs, CS/ECE m Nortel? HP? Cisco? Agilent? Compaq? Others? r Do cool, “hands on”, industrially-relevant, applied, practical, and exciting stuff!!