The paper investigates the dielectric properties of the (Ag_2SO_4)_x(AgPO_3)_1_-_x and (Ag_2SO)_x(AgPO_3)_1_-_x glasses by impedance measurements at low frequencies (l Hz to l0 MHz)and at high frequencies (8.2 GHz to l8 GHz) by waveguide measurements. The frequency dependence of a.c. conductivity has been interpreted in terms of translational and reorientational ionic hopping motion. The activation energies values extracted from the temperature dependence of fixed frequency a.c. conductivity agree with the values of the acoustic attenuation