1. 1 Internet Protocols and Network Performance Issues Carey Williamson iCORE Professor Department of Computer Science University of Calgary

2. 2 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...

3. 3 My Research Interests r Network Traffic Measurement r Workload Characterization r Traffic Modeling r Network Simulation r Web Performance r Adaptive Network Applications

4. 4 Network Traffic Measurement r Collect and analyze packet-level traces from a live network, using special equipment

5. 5 Network Traffic Measurement r Collect and analyze packet-level traces from a live network, using special equipment 101101

6. 6 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

7. 7 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

8. 8 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

9. 9 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

10. 10 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

11. 11 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

12. 12 Summary r Explore network performance issues r Understand current networking literature r Experiment with current and emerging Internet protocols, applications, services r Wireless Internet Performance Lab (UofC) r Experimental Laboratory for Internet Systems and Applications (UofS/UofC,CFI) r Do cool, “hands on”, industrially-relevant, applied, practical, and exciting stuff!!