  An efficient numerical algorithm is presented for massively parallel
simulations of dispersion-managed wavelength-division-multiplexed optical fiber
systems. The algorithm is based on a weak nonlinearity approximation and
independent parallel calculations of fast Fourier transforms on multiple CPUs.
The algorithm allows one to implement numerical simulations M/2 times faster
than a direct numerical simulation by a split-step method, where M is a number
of CPUs in parallel network.
