1. The Changing Usage of a Mature Campus-wide Wireless Network CS525m – Mobile and Ubiquitous Computing Andrew Stone

2. Worcester Polytechnic Institute 2 Overview Project Goal Data Collection Methods Findings and Data Analysis Conclusions and Recommendations

3. Worcester Polytechnic Institute 3 Project Goal Compare WLAN network usage statistics at Dartmouth college from fall 2001 and 2003/2004 –Number and type of devices –Applications in use Better understand user behavior

4. Worcester Polytechnic Institute 4 Networked Devices Voice over IP –PBX converted to VoIP in 2003 –Softphones and VoIP phones Client Devices –Laptops, PDAs, phones, etc identified by using tcpdump traces and an OS fingerprinting tool (p0f)

5. Worcester Polytechnic Institute 5 Networked Devices

6. Worcester Polytechnic Institute 6 Data Collection (2001) Analysis of a Campus-wide Wireless Network (2001) http://users.wpi.edu/~astone/mobilecomputing/kotzwlananalysis.pdf http://users.wpi.edu/~astone/mobilecomputing/kotzwlananalysis.pdf 476 802.11b APs over 161 buildings –430 were tracked 115 Subnets Syslog tracking started before –Contains authentication, association, and roaming information AP SNMP Polling for Client specific counters –MAC, IP, Signal Strength, traffic info

7. Worcester Polytechnic Institute 7 Data Collection (2003) 566 APs over 188 buildings <115 Subnets (started using VLANs) >75% of undergrads own laptops VOIP phone records 18 sniffers covering 121 APs (most popular areas from 2001)

8. Worcester Polytechnic Institute 8 Data Collection 2001 –Over 1700 different wireless cards –11 week period 2003 –Over 7000 different wireless cards –17 week period

9. Worcester Polytechnic Institute 9 Definitions Card, Session, Active card, Active AP, Roam, Roaming Session, Roamer Card, Inbound, Outbound Mobile session, Mobile card

10. Worcester Polytechnic Institute 10 Mobile Session Distance between any two APs in a session > ab, bc, cd, da, ac, or bd

11. Worcester Polytechnic Institute 11 Questions asked Has the population grown? Have usage patterns changed? Where do users visit?

12. Worcester Polytechnic Institute 12 Has the population grown?

13. Worcester Polytechnic Institute 13 Active cards per day (2001)

14. Worcester Polytechnic Institute 14 Active cards per day (2003)

15. Worcester Polytechnic Institute 15 Active cards per hour (2001)

16. Worcester Polytechnic Institute 16 Active cards per hour (2003)

17. Worcester Polytechnic Institute 17 Heavy User Distribution

18. Worcester Polytechnic Institute 18 Average active days per week per user

19. Worcester Polytechnic Institute 19 Average active days per week per user

20. Worcester Polytechnic Institute 20 Active APs per day

21. Worcester Polytechnic Institute 21 Active APs per day

22. Worcester Polytechnic Institute 22 Average Active cards per active AP per day

23. Worcester Polytechnic Institute 23 Average Active cards per active AP per day

24. Worcester Polytechnic Institute 24 Max cards per hour, for busiest buildings

25. Worcester Polytechnic Institute 25 Max cards per hour, for busiest buildings

26. Worcester Polytechnic Institute 26 Daily Traffic (GB)

27. Worcester Polytechnic Institute 27 Daily Traffic (GB)

28. Worcester Polytechnic Institute 28

29. Worcester Polytechnic Institute 29 Total traffic

30. Worcester Polytechnic Institute 30 Total Traffic

31. Worcester Polytechnic Institute 31 Near/Far Traffic

32. Worcester Polytechnic Institute 32 Near/Far Traffic

33. Worcester Polytechnic Institute 33 Average daily traffic per AP, by AP category

34. Worcester Polytechnic Institute 34 Average daily traffic per AP, by AP category

35. Worcester Polytechnic Institute 35 VoIP calls by hour

36. Worcester Polytechnic Institute 36 VoIP CCDF of call duration

37. Worcester Polytechnic Institute 37 P2P Total Traffic

38. Worcester Polytechnic Institute 38 P2P Near/Far Traffic

39. Worcester Polytechnic Institute 39 Streaming Media Total Traffic

40. Worcester Polytechnic Institute 40 Streaming Media Near/Far Traffic

41. Worcester Polytechnic Institute 41 Mobility Time spent at home location

42. Worcester Polytechnic Institute 42 Mobile Session duration

43. Worcester Polytechnic Institute 43 Mobility Session diameter, distribution across sessions, by application

44. Worcester Polytechnic Institute 44 Conclusions and Recommendations Found dramatic increase in usage and change in applications Because the majority of users stay in their home location network caching and prediction-based schemes may be beneficial Device profiling: single VLAN campus wide for VoIP and PDA devices and building subnets for laptops Compare wireless usage against wired usage

45. Worcester Polytechnic Institute 45 Future Work WLAN moving to 802.11a/b/g Campus Cable TV network migrating to IP-based streaming video Wireless sniffers

46. Worcester Polytechnic Institute 46 Thoughts and Questions?