  Mobile ip (mip) is an internet protocol that allows mobile nodes to have
continuous network connectivity to the internet without changing their ip
addresses while moving to other networks. The packets sent from correspondent
node (cn) to a mobile node (mn) go first through the mobile node's home agent
(ha), then the ha tunnels them to the mn's foreign network. One of the main
problems in the original mip is the triangle routing problem. Triangle routing
problem appears when the indirect path between cn and mn through the ha is
longer than the direct path. This paper proposes a new technique to improve the
performance of the original mip during the handoff. The proposed technique
reduces the delay, the packet loss and the registration time for all the
packets transferred between the cn and the mn. In this technique, tunneling
occurs at two levels above the ha in a hierarchical network. To show the
effectiveness of the proposed technique, it is compared with the original mip
and another technique for solving the same problem in which tunneling occurs at
one level above the ha. Simulation results presented in this paper are based on
the ns2 mobility software on linux platform. The simulations results show that
our proposed technique achieves better performance than the others, considering
the packet delay, the packet losses during handoffs and the registration time,
in different scenarios for the location of the mn with respect to the ha and
fas.

Networking and Internet Architecture