Systems and methods are provided for flexible wavelength assignments in a communication network. An optical adapter is provided for the systems and methods. The optical adapter has a first interface connected to an optical switch via a first optical cable, a second interface connected to a plurality of server ports via a plurality of second optical cables, and a controller coupled to a switch controller of the optical switch. The controller is configured to perform: obtaining instructions from the switch controller; and assigning, based on the instructions, one or more wavelengths for a time slot to one of the server ports, wherein the controller performs the assigning without direct communication with the server ports.