This study is based on the 2.5D numerical simulations of the large-amplitude oscillations (LAOs) in the flux rope solar prominences. The prominence models with two different values of the initial shear angle and the density contrast were considered. In order to investigate the possible normal modes of the structure, the prominence was perturbed with the horizontal and vertical disturbances. To study the mechanism of the external LAOs triggering, we used the disturbance placed out of the flux rope. The transverse and longitudinal oscillation periods do not show a strong dependence on the shear angle and the density contrast. The external perturbation excites the oscillations of both polarizations, and their properties are a mixture of those excited by purely horizontal and vertical driving.