1. RealProct: Reliable Protocol Conformance Testing with Real Nodes for Wireless Sensor Networks
Junjie Xiong

2. Outline
Motivation
RealProct Design
Evaluation
Conclusion

3. Motivation
Wireless sensor networks (WSNs) are vulnerable to software bugs.
Simulation is different from real execution.
Testbeds are designed for network performance evaluation rather than software bug detection.
Large-scale real deployment is expensive.
RealProct uses a small number of real sensor nodes to mimic large-scale WSNs and test the protocol against the specification.

4. Outline
Motivation
RealProct Design
Evaluation
Conclusion

5. Challenges Sensor nodes are resource-constrained devices.
Sensor node is difficult to control than a computer.
Volatile wireless environment in WSNs will result in random packet loss.
How to test the protocol with various topologies and events when RealProct only employs a few real sensor nodes.
Emphasis on my own work

6. Protocol Conformance Testing Process
PCT process
IUT (Implementation Under Test)
Emphasis on my own work 6 6

7. RealProct Architecture
Point of Control & Observation
SUT (System Under Test)
Upper Tester
Lower Tester
Emphasis on my own work 7 7

8. Topology Virtualization
Emphasis on my own work 8 8

9. Event Virtualization
Packet disorder
Emphasis on my own work 9 9

10. Test Execution and Verdict
Suppose packet loss probability is L0, a test case is executed n times, and it passes n1 times and fails n2 times.
If n1 > n2, declare as pass, the false negative probability is
Let the FN error rate be lower than Th, then the minimum n is
Emphasis on my own work 10 10

11. Outline
Motivation
RealProct Design
Evaluation
Conclusion

12. Performance Evaluation
Two real TelosB sensor nodes and a PC.
Contiki 2.4: μIP TCP/IP protocol.
Two new bugs and previous bug repetition.
Bug 1 & 2 – Connect to opened & unopened TCP ports.
Bug 3 – An SYN/ACK packet loss.
Bug 4 – SYN packet duplication.

13. Performance Evaluation
Bug 1 – Connect to opened TCP ports.
Test opened port 0 & 80 (within 0 to 65535).
TCP connection are from 0 to 65535: test opened port 0 & 80.

14. Performance Evaluation
Bug 1 – Connect to opened TCP ports.
Test opened port 0 & 80 (within 0 to 65535).
TCP connection are from 0 to 65535: test opened port 0 & 80.

15. Performance Evaluation
Bug 2 – Connect to unopened TCP ports.

16. Outline
Motivation
RealProct Design
Evaluation
Conclusion

17. Conclusion
As a protocol testing tool, RealProct finds two new bugs, discovers all the previously detected bugs in the TCP/IP stack, and validates the Rime mesh routing protocol.
Propose two techniques, topology virtualization and event virtualization, for testing.
Design an algorithm to tackle the inaccuracy problem caused by non-deterministic events in test execution.

18. Q & A Thank you!