Using an emulation testbed to measure OSPF routing overhead due to mobility in wireless ad hoc networks

Abstract

In mobile wireless IP networking domains (i.e., MANETs), the network topology may be frequently changing due to node mobility. Under such network dynamics, simulation has shown that the OSPF routing protocol performs poorly (e.g., increased overhead and data loss), but can be modified with dasiaMANET extensionspsila to better its performance. To provide complementary validation of these observations, this paper separately measures the routing protocol overhead generated by OSPF and its MANET extensions due to node mobility using an emulation testbed. The networking experiments were constructed using several off-the-shelf Linux workstations interconnected by Ethernet. Several modeling efforts were necessary to represent the network under testpsilas partial mesh connectivity, wireless interfaces, and node mobility on the immobile, non-wireless testbed. To validate these modeling efforts, the experimental results from the emulation testbed were cross-validated against OPNET simulation. For networks under test of increasing size, our emulation (and simulation) testing showed that the MANET extensions to OSPF consistently exhibited lower amounts of routing protocol overhead, and lower growth trends, when compared to OSPF. Our emulated results reaffirm previous simulation efforts.