1. Simulation Debugging and Visualization in the Mobius Modeling Framework
Craig Buchanan and Ken Keefe
Information Trust Institute, University of Illinois at Urbana-Champaign
QEST Florence, Italy - September 09, 2014

2. Overview 1. Motivation and Goals 2. Simulator Overview
3. MSDV Features
4. MSDV Implementation
5. Case Study (AMI)
6. Conclusion

3. Motivation Model complexity - Difficult validation/verification
- Model understanding
- Human error
What problems are we facing?
model complexity in both model creation and model analysis
Increased model credibility through validation and verification
Validation - Conforms to modeling formalism and model correctly represents system under consideration
Verification - model executing as expected

4. Goals Highly transparent view of running simulation Subgoals
- Adaptable Modules
- Atomic Model Implementation
- Composed Model Implementation
Why running?
- complex simulation take a long time to complete
- mistakes can cause simulation to not complete
- enabled tweaking model parameters during the simulation

5. Simulator Overview Mobius Discrete Event Simulator - State Variables
- Actions
- Future Event List

6. State Variable Represents state of a model component - M ≈ {SV} SV0 A0
Model state = set of all SVs
SV0 = 2
SV1 = 0

7. Action Represents changes in model state
- Associated with timing distribution (Exponential, Weibull, etc.)
- Enabled/disabled
SV0 A0
SV1

8. Future Event List Sequence of events in simulation
- Event = [action, t]
- FEL = {E}
SV0 A0
SV1

9. MSDV Features Model state analysis Model state modification
Breakpoints
Simulation stepping
Model state visualization

10. Model State Analysis M = { {SV}, FEV} t = 1.00 t = 1.50 t = 0.0
FEL = { {A0, 1.00}, {A2, 1.75} }
FEL = { {A1, 1.50}, {A2, 1.75}, {A0, 2.00} }
FEL = { {A2, 1.75}, {A0, 2.00} }
FEL = { }
Abstract Functional Interface
A2 (1.75)

11. Model State Modification
SV0
A0 (1.00)
SV1
A1 (0.50)
SV2
FEL = { {A0, 1.00}, {A2, 1.75} }
FEL = { {A1, 1.50}, {A2, 1.75}, {A0, 2.00} }
FEL = { {A1, 1.50} }
FEL = { {A1, 2.00} }
FEL = { }
A2 (1.75)

12. Breakpoints - Simulation time breakpoint - Action breakpoint
- State variable breakpoint

13. Simulation Stepping Next-event breakpoint
(Implicit breakpoint on every action)

14. MS Visualization (AFI)

15. MS Visualization (SAN)

16. Implementation

17. Case Study - Attack on AMI
Advanced metering infrastructure (AMI)

18. Case Study - AMI (cont.)

19. Case Study - AMI (cont.)
Deploy dedicated intrusion detection system (IDS)

20. Case Study - AMI (cont.)

21. Case Study - AMI (cont.)
Attack token paths

22. Case Study - AMI (AFI)

23. Case Study - AMI (SAN)

24. Conclusion - Debugging and visualization on running simulations
- Increased model credibility (validation/verification)
- Features
- Analysis
- Modification
- Breakpoints
- Stepping
- Visualization

25. Questions?