An Efficient Cyclic-Quorum-Based Fault-Tolerant Approach for Mobility Agents in Mobile IP Networks

Abstract

In mobile IP protocol, if a Home Agent (HA) fails, the Mobile nodes (MNs) served by it will not be able to communicate with others. Although some researches have proposed different mechanisms to solve the fault-tolerance problem, this study has proposed an efficient cyclic-quorum-based fault-tolerant protocol to solve it. In a network with N HAs, all the HAs are grouped into N quorums with logical circular structure. A HA has 「√N」 backup quorums and divides the network that it manages into 「√N」equal segments, each of which is associated with one of its backup quorums. Thus, for a MN, according to its home address, its binding is stored in 「√N」-1 backup HAs of the associated backup quorum. When a HA fails, the system will select the HA with minimum load from each backup quorum to take over the faulty HA. In comparison with previous related works, the simulation results showed that the proposed fault-tolerant protocol has many advantages, including better system load balance, less latency for registration process, less backup bindings, and no extra hardware cost.