Apparatus and method for scheduling on an optical ring network

An example method includes receiving at a scheduling server status information concerning at least one transmit queue for a plurality of optical pass-through switches (OptSws). A schedule for transmissions to take place is determined based on the status information for the OptSws. A control message is forwarded to the plurality of OptSws in order that the schedule may be implemented. In an embodiment, a schedule is determined for a wavelength available to transmit a transmission by removing unsupportable transmissions from a candidate transmission list, determining a first transmission that is the one of the transmissions of the candidate transmission list which most preferably satisfies a given parameter, updating a usage list to reflect determination of the first transmission; and replacing the candidate transmission list with the residue set of the first transmission. The usage list reflects transmissions determined by the scheduler.