Design and Analysis of Replicated Servers to Support IP-Host Mobility in Enterprise Networks

Mobility support in IP networks requires the use of servers to forward packets to mobile hosts and to maintain information pertaining to a mobile host’s location in the network. In one proposed protocol, the mobile-IP protocol, location and packet forwarding functions are provided by servers referred to as home agents. These home agents may become the bottleneck when there are a large number of mobile hosts in the network. In this paper, we consider the design and analysis of load balancing mechanisms for multiple home agents in the mobile-IP protocol. We propose a load balancing scheme in which a home agent may periodically transfer the control of a mobile host to another home agent in the same network through the use of functions supported in mobile-IP. The periodicity with which this transfer is performed affects the load balancing gain as well as the associated overhead. We analyze our load balancing mechanism under bursty traffic arrival conditions using a Markov Modulated Poisson Process. The results show that the proposed load balancing scheme can yield modest gains over alternative load balancing strategies.