Structured shelf

In an optical transmission node, a plurality of shelves, respectively connected to a plurality of optical cables having limitations on bending radius, are stored in one rack of the node. In a shelf body thereof, the first and second opening portions are made in a front surface, and an extra-cable looping device loops an extra portion of the optical cable, further a moving mechanism is provided for moving the extra-cable looping device to avoid a space occupied by the units in a state removed from the second opening portion, this enables extra-cable handling within a limited spatial range and the insertion/removal of the units having various functions from the shelf in a state where the cable is active and further the improvement of a shelf mounting density per rack.