ITU-T G.872

Abstract

This Recommendation describes the functional architecture of optical transport networks using the modelling methodology described in [ITU-T G.800] and [ITU-T G.805]. The optical transport network (OTN) functionality is described from a network level viewpoint, taking into account an optical network layered structure, client characteristic information, client/server layer associations, networking topology, and layer network functionality providing optical signal transmission, multiplexing, routing, supervision, performance assessment and network survivability. The optical portion of the network is described in terms of spectrum management entities and maintenance entities. <br>This Recommendation is restricted to the functional description of optical transport networks that support digital signals. The support of analogue or mixed digital/analogue signals is outside the scope of this Recommendation. <br>It is recognized that the design of optical networks is subject to limitations imposed by the accumulation of degradations introduced by the number of network elements and their network topology. However, many of these degradations and the magnitude of their effects are associated with particular technological implementations of the architecture described in this Recommendation and are therefore subject to change as technology progresses. As such, the description of these effects is outside the scope of this Recommendation.