  Ultra-high energy ($E_\nu>10^8 $ GeV) neutrino-nucleon total cross sections
$\sigma^{\nu N}$ are estimated from a soft non-perturbative model complemented
by an approximate QCD evolution, explicitly calculated. The resulting
asymptotic energy behavior of the neutrino-nucleon charged-current total cross
section is derived analytically and predictions concerning the observation of
ultra-high energy neutrinos in future experiments are presented.
