We investigate the nonlinear dynamics of dual-frequency-pumped four-wa
ve mixing in both the normal- and the anomalous-dispersion regime of o
ptical fibers. We compare the exactly integrable dynamics of a truncat
ed system of nonlinear ordinary differential equations for the first f
our modes of the multiwave mixing interaction with the phase-plane pro
jections of the numerical solutions of the nonlinear Schrodinger equat
ion.