Ion transport through a Ca30 glass, a sodium ion (Na + ) conductor, has been induced by bombardment with a potassium ion (K + ) beam. The measurement of back side ion currents as a function of the ion beam kinetic energy by means of the recently developed BIIT (bombardment induced ion transport) approach allows determining the conductivity of the material. Measurement of this conductivity as a function of the temperature allows deriving the activation energy for ion transport as 0.99 eV ± 0.01 eV in perfect agreement with impedance spectroscopy. While the conductivity as well as the activation energy clearly correspond to the bulk property, i.e. the transport of Na + , depth profiling of the glass sample after the BIIT experiment exhibits K + profiles reaching up to 100 nm into the glass. Ultimately, modeling of the experimental data by means of the Nernst–Planck–Poisson theory provides access to a quantitative understanding of the conductivities and the diffusion profiles under the condition of competing Na + /K + ion transport.