An Efficient Quorum-based Fault-Tolerant Approach for Mobility Agents in Wireless Mobile Networks

1. An Efficient Quorum-based Fault-Tolerant Approach for Mobility Agents in Wireless Mobile Networks Yeong-Sheng Chen Chien-Hsun Chen Hua-Yin Fang Department of Computer Science, National Taipei University of Education

2. Outline • Introduction • Related Work • Cyclic Quorum-based Replication Mechanism • Performance Evaluation • Conclusion

3. Introduction • Mobile IP Protocol is a protocol to support Hosts mobility. • The architecture of mobile IP • Mobile Host (Mobile Node) • Mobility Agent • Home Agent • Foreign Agent

4. Introduction HA RAN Router MN Home Agent Radio Access Network

5. Introduction FA FA RAN HA Router Router Internet Router Router Router MN FA FA

6. Register HA allocates an address and maintains the MN Introduction FA FA RAN HA Router Router Internet Router Router Router Send data to A through HA and FA1 Router MN FA FA1 A

7. Allocate CoA or DHCP Request Care-of Address Tell HA stores MN’s CoA MN Introduction FA FA RAN HA Router FA FA

8. MN Introduction FA FA RAN HA A wants to send data to MN Router FA A FA

9. Introduction • In multiple mobility agents environment, data will be distributed stored in the different agent. • Distributed data processing will cause some problem • Fault tolerance • Registration delay • Load balance

10. Introduction • HA crashed FA FA HA MN FA FA

11. Introduction • To offer solutions to these problems, many fault-tolerant approaches have been proposed.

12. Registration request Related Work- FTMIPP Update HA’s bindings R. Ghosh and G. Varghese, “Fault-Tolerant Mobile IP,”Technical Report WUCS-98-11, Washington Univ., Apr. 1998. FA RAN HA Router Router Acquire Home Address under HA Router A Update HA’s bindings FA

13. Related Work- FTMIPP • The drawback of FTMIPP • Long registration time • Low resource utilization • Conclusion • Use fully redundant mobile agent to solve fault tolerant problem

14. Manage the region belong to HA Related Work Response Search MNs Request to store the bindings FA HA FA Detect failed OA&M (Operation Administration and Maintenance) A FA J. W. Lin and J. Arul, “An Efficient Fault-Tolerant Approach for Mobile IP in Wireless Systems,” IEEE Transactions on Mobile Computing, VOL. 2, NO. 3, Jul.-Sep. 2003. .

15. Related Work Request to Restore FA HA FA HA recovered OA&M A FA

16. Related Work • The drawback of the scheme • Spend extra time on • Searching MNs • Delivering bindings • Extra hardware cost

17. Goal • The backup mechanism • should maintain and backup bindings efficiently • should not bring heavy system load • should balance • Many researches use quorum-based mechanisms to backup data in distributed systems.

18. Cyclic Quorum-based Replication Mechanism • Assumption • Not all HAs of a quorum in a home network will fail at the same time. • Whenever a HA crashes, any data in the volatile media of the HA will be gone • The failure occurs in the network only by reason of the faulty HA • The home network will divide into several network segments and each HA will take charge of one of the segments.

19. Cyclic Quorum-based Replication Mechanism • To balance the backup load, the author uses quorum to achieve the goal • Per-allocate the storage place with location by using quorum

20. Cyclic Quorum-based Replication Mechanism • Cyclic Quorum-based could balance the load 3 ….. 4 N-1 N 2 1

21. Cyclic Quorum-based Replication Mechanism • M. J. Yang, Y. M. Yeh, and Y. M. Chang, “Legion Structure for Quorum-Based Location Management in Mobile Computing,”Journal of Information Science and Engineering, Vol. 20, pp. 191-202, 2004.

22. Cyclic Quorum-based Replication Mechanism • There are N HAs in the networks and N distinct quorum • According to Cyclic Quorum, each HAs need backup bindings of other HAs 3 ….. 4 N-1 N 2 1

23. 8 1 7 2 3 6 4 5 Cyclic Quorum-based Replication Mechanism • Example: • There are 8 MAs in the network • The Quorum sets ={Q1,Q2,Q3….,Q8} • Ex. Q1={HA1,HA2,HA3}, Q2={HA2,HA3,HA4}, Q3={HA3,HA4,HA5},……Q8={HA8,HA1,HA2} • HA1 selects Q1, HA2 selects Q2 …………,HAN selects QN

24. 8 8 8 8 8 8 8 8 1 1 1 1 1 1 1 1 7 7 7 7 7 7 7 7 2 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 6 6 6 6 6 6 6 6 4 4 4 4 4 4 4 4 5 5 5 5 5 5 5 5 Cyclic Quorum-based Replication Mechanism Q2 Q1 Q3 Q4 Q5 Q6 Q7 Q8

25. 8 8 8 1 1 1 7 7 7 2 2 2 3 3 3 6 6 6 4 4 4 5 5 5 Cyclic Quorum-based Replication Mechanism • HA1 stores in 3 quorums • EX. HA1 stores in {Q1,Q7,Q8} for backup Q7 Q1 Q8

26. Cyclic Quorum-based Replication Mechanism • HA1 will sends the bindings to HA7 and HA8 periodly HA1 RAN Router Router Router MN HA8 HA7

27. 8 8 8 1 1 1 7 7 7 2 2 2 3 3 3 6 6 6 4 4 4 5 5 5 Cyclic Quorum-based Replication Mechanism • If HA1 failed, HA7 and HA8 will takeover the member of HA1 Q7 Q1 Q8

28. 8 8 8 1 1 1 7 7 7 2 2 2 3 3 3 6 6 6 4 4 4 5 5 5 Cyclic Quorum-based Replication Mechanism • If HA1recovers, HA7 and HA8 will sends the bindings to HA1 Q7 Q1 Q8

29. Performance Evaluation • Simulator :QualNet • Compare with FTMIPP

30. Performance Evaluation FTMIPP CQFTP Bindings per backup HA Number of MNs

31. Performance Evaluation FTMIPP CQFTP Extra Backup Message Number of MNs

32. Performance Evaluation FTMIPP CQFTP Number of registered MN per Backup HA 9 16 25 36 49 64 81 Number of Multiple HAs

33. Performance Evaluation FTMIPP CQFTP Average Registration Delay (Sec) 2 4 6 8 10 12 14 16 18 20 Number of Multiple HAs

34. Performance Evaluation FTMIPP CQFTP Average Registration Delay (Sec) Mobility Rate

35. Conclusion • The authors proposed a mechanism • Don’t need any extra hardware cost • Reduce backup bindings by using the small quorum size • Balance the load of take over process • Low registration overhead