Models of ionic conductivity in disordered glass structures are reviewed and discussed, using data for 0.35Li(2)S + 0.65GeS(2) with mobile Li+ ions as an example. The basic mechanism for conductivity and NMR spin-lattice relaxation is random ionic hops over a distribution of barriers, which gives complex ac and de conductivities as Debye responses to the microscopic thermal motion and the macroscopic ion drift. The macroscopic sigma(dc) can be calculated from random walk percolation over the lowest barriers in a distribution determined by NMR.