All-in-interworking technology, based on IEEE 802.3 standard, was mainly developed for the separable media cabling and transmission speed increase. Although the high speed networking is already provided by a fiber optic cable, coaxial guides are in demand for similar applications. Time-domain analysis is undertaken to estimate electrodynamic states of inner and outer guiding conductors at periodic bipolar pulses propagation on a coaxial cable. An electric current density distribution on the cross-section of the inner conductor is obtained from a solution of Maxwell’s equations under periodic boundary conditions that are prescribed by a product of two function such as the first of them is introduced implicitly for a profile of surface current density in the axial direction, while the other determines this profile transient states. As for shielding braid, which is the cable outer conductor, its current density distribution is derived from an analysis of field harmonics penetrating into conductive subsurface layers under similar boundary conditions. It is also shown that prescribed implicative boundary conditions for both conductors allow to obtain, at least under auxiliary assumption, some completed formulae useful to the pulses duration admissible decrease estimation at their transmission on the coaxial cable. The paper contains some comparative and numerical results as well.