A node is configured to receive an instruction to establish a channel having a bandwidth that corresponds to an operating spectrum an optical fiber; obtain information that identifies a channel spacing and a pointer that identifies where, within the spectrum, to establish bandwidth allocations; identify a group of bandwidth segments based on the spectrum and the channel spacing; and generate bit words that correspond to the bandwidth allocations, where the bit words includes bits that, when set to a value, cause sets of segments to be reserved within the spectrum, and where the sets of segments identify where the bandwidth allocations begin and end, within the spectrum, relative to the pointer.