Abstract: An add/drop node of an optical WDN-network which has two fiber paths for light of a plurality of channels propagating in opposite directions comprises two add/drop modules (231, 23r) for each of the channels. All the modules are identically constructed. Each module comprises an add device (251, 25r) for adding light to one of the paths and a drop device (27r, 271) for deflecting a portion of light from a second one of the paths. A module comprises a house (41) enclosing the add device and the drop device. A first fixed connector (53, 73) is attached to the house for connection in the first path and to a an optical fiber (45, 65) which extends freely from the house and has a first free connector (43, 63) at its free end to be attached to the fixed connector of a neighbouring add/drop module for continuing the first path through the considered add/drop module to the neighbouring module.