A digital wrapper called an optical transport network (OTN) wraps data frames and enables the transmission of data from numerous sources over the same channel. For each client signal, this establishes an optical virtual private network. An optical transport network, according to ITU-T, is a collection of Optical Transport Network Market linked by optical fibre links and capable of managing, supervising, transporting, multiplexing, switching, and maintaining the viability of optical channels carrying client signals. An ONE can be pure photonic or it can re-time, re-amplify, and re-shape (3R) an object. It cannot be OTN if the links are not optical fibre. If the communications are not transmitted by optical fibre, then switching, management, and supervision alone are insufficient to qualify as OTN.
