Described in the ITU-T G.709 Recommendation (2003) "Interface for the Optical Transport Network (OTN)," digital wrapper is a method for encapsulating an existing frame of data, regardless of the native protocol, to create an optical data unit (ODU) similar to that used in SDH/SONET. A digital wrapper, however, allows multiple existing frames of data to be wrapped together into a single entity that can be more efficiently managed through a lesser amount of overhead. A digital wrapper includes a Reed-Solomon forward error correction (FEC) mechanism that improves error performance on noisy links. Digital wrappers have been defined for 2.5-, 10-, and 40-Gbps systems. See also digital, error control, FEC, ITU-T, link, OTN, protocol, Reed-Solomon, and wavelength.