The invention relates to a method for controlling access to an out-of-band communication channel in an optical communications network comprising a master device and slave devices connected to the master device via optical fiber, the optical communications network being adapted to enable in-band communications, the out-of-band communication channel being intended to enable transmissions of signalling signals with respect to the in-band communications. The master device processes signalling signals transmitted by said slave devices without access restriction to the out-of-band communication channel; and upon detecting a collision between signalling signals transmitted by slave devices concurrently accessing the out-of-band communication channel, the master device initiates a temporary time-slotted access to the out-of-band communication channel, so as to restrict access to the out-of-band communication channel by time slot distribution among slave devices likely to concurrently access the out-of-band communication channel using carrier wavelengths substantially identical as those having involved the detected collision.