Internet Protocols and Network Performance Issues Carey Williamson

Internet Protocols and Network Performance Issues Carey Williamson Professor/i. CORE Senior Research Fellow Department of Computer Science University of Calgary 1

Internet Protocol Stack r Application: supporting network applications and end-user services m FTP, SMTP, HTTP, DNS, NTP Application r Transport: end to end data transfer m TCP, UDP Transport r Network: routing of datagrams from Network source to destination m IPv 4, IPv 6, BGP, RIP, routing protocols r Data Link: hop by hop frames, channel access, flow/error control m PPP, Ethernet, IEEE 802. 11 b Data Link Physical 001101011. . . r Physical: raw transmission of bits 2

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

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

Network Traffic Measurement r Collect and analyze packet-level traces from a live network, using special equipment 101 5

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) 101 6

Workload Characterization r Try to understand the salient features of network, protocol, application, and user behaviour on the Internet r Example: Web server workloads [Arlitt 96] m m Zipf-like document referencing behaviour Lots of “one-time” referencing of documents Heavy-tailed file size distributions Self-similar network traffic profile 7

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 m Web client workload model MPEG compressed video model Self-similar Ethernet LAN traffic model Synthetic Web proxy workload generator 8

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 m m Improving Web performance over ADSL Understanding the effects of user mobility on Mobile IP routing and protocol performance Studying the design, scalability, and performance of Web server and Web proxy caching architectures 9

Web Performance r Explore techniques to improve the performance and scalability of the Web r Examples: m m m Clustered Web servers Load balancing policies Web prefetching strategies Web proxy caching architectures Improvements to HTTP and TCP protocols 10

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 m m Web content for Java-enabled phones Multicast support for mobile users Location-aware routing optimizations Wireless-aware TCP protocol File system support for mobile users 11

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