Des is correct, because the act of pushing the pole would cause the lattice to compress slightly, from which the reaction force manifests itself as a wave moving along the pole. therefore, the maximum speed of communication attained would be the speed of sound in the medium the pole is constructed from. For example, if the pole was made of iron, the speed of the impulse would travel at 5120m/s, a measly 0.0017% the speed of light.