  We review recent progress on the theory of dynamics of polymer translocation
through a nanopore based on the iso-flux tension propagation (IFTP) theory. We
investigate both pore-driven translocation of flexible and a semi-flexible
polymers, and the end-pulled case of flexible chains by means of the IFTP
theory and extensive molecular dynamics (MD) simulations. The validity of the
IFTP theory can be quantified by the waiting time distributions of the monomers
which reveal the details of the dynamics of the translocation process. The IFTP
theory allows a parameter-free description of the translocation process and can
be used to derive exact analytic scaling forms in the appropriate limits,
including the influence due to the pore friction that appears as a finite-size
correction to asymptotic scaling. We show that in the case of pore-driven
semi-flexible and end-pulled polymer chains the IFTP theory must be augmented
with an explicit {\it trans} side friction term for a quantitative description
of the translocation process.
