Feedforward control of optical amplifiers is mandatory in wavelength routed networks to avoid traffic interruption resulting from fast input power variations. Effects limiting the efficiency of this control technique are discussed and an overview over techniques compensating for the most important ones is presented. Detailed insight into the wavelength dependence of the optimum pump power setting is provided by a mathematical model. Taking this dependence into account requires to filter the input signal. Three different techniques are explained that make use either of an additional filter placed in front of the input monitor, an embedded gain–flattening filter, or even the erbium–doped fiber itself. Timing is another important issue. Besides introducing a delay in front of the first doped fiber, sophisticated control schemes working without additional optical components by modifying the waveform of the pump signal are analyzed. Different setups such as cascaded amplifier stages with intermediate dispersion compensating fiber are considered. The stages are either controlled individually or are coupled via a pump splitter. Finally, solutions complementing the pump power control by fast adaptation of the attenuation of a variable attenuator are contemplated.