All-optical gate control signal generation is demonstrated from flag pulses, using a Fabry–Pérot filter followed by a semiconductor optical amplifier. Ten control pulses are generated from a single flag pulse having less than 0.45-dB amplitude modulation. By doubling or tripling the number of flag pulses, the number of control pulses increases approximately by a factor of two or three. The circuit can control the switching state of all-optical switches, on a packet-by-packet basis, and can be used for nontrivial network functionalities such us self-routing.