Recently, Mobile Ad-hoc Networks (MANETs) have an increased interest in applications for covering rural areas due to the possibility of usage of low-cost and high-performance mobile terminals, without having to depend on the network infrastructure. Because the terminals are mobile, the routes change dynamically, so routing algorithms are an important issue for operation of MANETs. In this paper, we investigate the behaviour of OLSR Routing Protocol for different ETX algorithms. We conduct experiments in a MANET testbed. We consider different HELLO packets interval of OLSR and compare ETX_ff and ETX_float link quality metrics. We design and implement two experimental scenarios in our academic environment and investigate their performance behaviour for different number of hops.