Title: Wireless Internet Performance Research
1Wireless InternetPerformance Research
- Carey Williamson
- iCORE Professor
- Department of Computer Science
- University of Calgary
2Internet Protocol Stack
- Application supporting network applications and
end-user services - FTP, SMTP, HTTP, DNS, NTP
- Transport end to end data transfer
- TCP, UDP
- Network routing of datagrams from source to
destination - IPv4, IPv6, BGP, RIP, routing protocols
- Data Link hop by hop frames, channel access,
flow/error control - PPP, Ethernet, IEEE 802.11b
- Physical raw transmission of bits
001101011...
3The Wireless Web
- The emergence and convergence of these
technologies enable the wireless Web - the wireless classroom
- the wireless workplace
- the wireless home
- My iCORE mandate design, build, test, and
evaluate wireless Web infrastructures - Holy grail anything, anytime, anywhere access
to information (when
we want it, of course!)
4Research Interests
- Wireless Internet Technologies
- Web Performance
- Network Traffic Measurement
- Workload Characterization
- Traffic Modeling
- Network Simulation
- Network Emulation
5Wireless Internet Technologies
- Mobile devices (e.g., notebooks, laptops, PDAs,
cell phones, wearable computers) - Wireless network access
- Bluetooth (1 Mbps, up to 3 meters)
- IEEE 802.11b (11 Mbps, up to 100 meters)
- IEEE 802.11a (55 Mbps, up to 20 meters)
- Operating modes
- Infrastructure mode (access point)
- Ad hoc mode
- Classroom area networks (CRAN)
6Example
- Multi-hop ad hoc networking
Gwen
Carey
7Example
- Multi-hop ad hoc networking
Gwen
Carey
8Example
- Multi-hop ad hoc networking
Gwen
Carey
9Example
- Multi-hop ad hoc networking
Gwen
Carey
10Example
- Multi-hop ad hoc networking
Gwen
Carey
11Example
- Multi-hop ad hoc networking
Gwen
Carey
12Example
- Multi-hop ad hoc networking
Gwen
Carey
13Example
- Multi-hop ad hoc networking
Gwen
Carey
14Example
- Multi-hop ad hoc networking
Gwen
Carey
15Example
- Multi-hop ad hoc networking
Gwen
Carey
16Web Performance
- Explore techniques to improve the performance and
scalability of the Web - Examples
- Clustered Web servers
- Load balancing policies
- Web prefetching strategies
- Web proxy caching architectures
- Improvements to HTTP and TCP protocols
17Network Traffic Measurement
- Collect and analyze packet-level traces from a
live network
18Network Traffic Measurement
- Collect and analyze packet-level traces from a
live network, using special equipment
101101
19Network Traffic Measurement
- Collect and analyze packet-level traces from a
live network, using special equipment - Process traces, statistical analysis
- Diagnose performance problems (network,
protocol, application)
101101
20Example Trace
0.000000 192.168.1.201 -gt 192.168.1.200 60 TCP
4105 80 1315338075 1315338075 0 win 5840
S 0.003362 192.168.1.200 -gt 192.168.1.201 60 TCP
80 4105 1417888236 1417888236 1315338076 win
5792 SA 0.009183 192.168.1.201 -gt 192.168.1.200
52 TCP 4105 80 1315338076 1315338076 1417888237
win 5840 A 0.010854 192.168.1.201 -gt
192.168.1.200 127 TCP 4105 80 1315338076
1315338151 1417888237 win 5840 PA 0.014309
192.168.1.200 -gt 192.168.1.201 52 TCP 80 4105
1417888237 1417888237 1315338151 win 5792
A 0.049848 192.168.1.200 -gt 192.168.1.201 1500
TCP 80 4105 1417888237 1417889685 1315338151
win 5792 A 0.056902 192.168.1.200 -gt
192.168.1.201 1500 TCP 80 4105 1417889685
1417891133 1315338151 win 5792 A 0.057284
192.168.1.201 -gt 192.168.1.200 52 TCP 4105 80
1315338151 1315338151 1417889685 win 8688
A 0.060120 192.168.1.201 -gt 192.168.1.200 52 TCP
4105 80 1315338151 1315338151 1417891133 win
11584 A 0.068579 192.168.1.200 -gt 192.168.1.201
1500 TCP 80 4105 1417891133 1417892581
1315338151 win 5792 PA 0.075673 192.168.1.200 -gt
192.168.1.201 1500 TCP 80 4105 1417892581
1417894029 1315338151 win 5792 A 0.076055
192.168.1.201 -gt 192.168.1.200 52 TCP 4105 80
1315338151 1315338151 1417892581 win 14480
A 0.083233 192.168.1.200 -gt 192.168.1.201 1500
TCP 80 4105 1417894029 1417895477 1315338151
win 5792 A 0.096728 192.168.1.200 -gt
192.168.1.201 1500 TCP 80 4105 1417896925
1417898373 1315338151 win 5792 A 0.103439
192.168.1.200 -gt 192.168.1.201 1500 TCP 80 4105
1417898373 1417899821 1315338151 win 5792
A 0.103780 192.168.1.201 -gt 192.168.1.200 52 TCP
4105 80 1315338151 1315338151 1417894029 win
17376 A 0.106534 192.168.1.201 -gt 192.168.1.200
52 TCP 4105 80 1315338151 1315338151 1417898373
win 21720 A 0.133408 192.168.1.200 -gt
192.168.1.201 776 TCP 80 4105 1417904165
1417904889 1315338151 win 5792 FPA 0.139200
192.168.1.201 -gt 192.168.1.200 52 TCP 4105 80
1315338151 1315338151 1417904165 win 21720
A 0.140447 192.168.1.201 -gt 192.168.1.200 52 TCP
4105 80 1315338151 1315338151 1417904890 win
21720 FA 0.144254 192.168.1.200 -gt 192.168.1.201
52 TCP 80 4105 1417904890 1417904890 1315338152
win 5792 A
21Key X Data Packet Ack Packet
X
X
X
X
X
SeqNum
X
X
X
X
X
X
X
X
X
Time
22Workload Characterization
- Try to understand the salient features of
network, protocol, application, and user
behaviour on the Internet - Example Web server workloads Arlitt96
- Zipf-like document referencing behaviour
- Lots of one-time referencing of documents
- Heavy-tailed file size distributions
- Self-similar network traffic profile
23Traffic Modeling
- Construct programs and statistical models that
capture the empirically-observed network traffic
behaviours - Allows flexible, controlled, repeatable
generation of workloads for experiments - Examples
- Web client workload model
- MPEG compressed video model
- Self-similar Ethernet LAN traffic model
- WebTraff GUI Web proxy workload generator
24Network Simulation
- Use computer simulation to study the packet-level
behaviour of the Internet, its protocols, its
applications, and its users - Examples
- 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
25Network Emulation
- A hybrid performance evaluation methodology that
combines simulation and experimental
implementation - A simulator that talks back (IP packets)
- Examples
- Web server benchmarking
- Wide Area Network (WAN) emulation
- Web proxy cache performance
- Distributed applications (Internet games)
26Summary
- Wireless Internet Performance Lab (UofC)
- Experimental Laboratory for Internet Systems and
Applications (UofS/UofC,CFI) - iCORE Research Team
- Five full-time research staff (Web, perf. eval.,
simulation, wireless, traffic modeling, network
measurement) plus 7 graduate students - Research Collaborations
- UofC, UofA, UofS, TRLabs, CS/ECE
- HP, Telus Mobility, SaskTel, Sun, Nortel
- Do cool, hands on, industrially-relevant,
applied, practical, and exciting stuff!!