  The study of the electromagnetic form factors of the nucleon in both the
space-like and time-like domains plays a key role for the understanding of the
internal structure and dynamics of this basic building block of the matter.
Form factors are also necessary for the interpretation of many other
measurements in reactions involving nucleons. In spite of being under
investigation by more than fifty years, they are far from being fully exploited
and more efforts devoted to their experimental determination are needed. Here,
we discuss the possibility of a complete measurement of the nucleon form
factors, both moduli and phases, in the time-like region at Frascati with the
DA$\Phi$NE electron-positron storage ring upgraded in energy.
