  In this paper, we study heliospheric Ly-$\alpha$ absorption toward nearby
stars in different lines of sight. We use the Baranov-Malama model of the solar
wind interaction with a two-component (charged component and H atoms)
interstellar medium. Interstellar atoms are described kinetically in the model.
The code allows us to separate the heliospheric absorption into two components,
produced by H atoms originating in the hydrogen wall and heliosheath regions,
respectively. We study the sensitivity of the heliospheric absorption to the
assumed interstellar proton and H atom number densities. These theoretical
results are compared with interstellar absorption toward six nearby stars
observed by the Hubble Space Telescope.
