This Recommendation describes the functional architecture of the metro transport network (MTN) using the modelling methodology described in [ITU T G.800], and [ITU T G.805]. MTN is primarily intended to support transport of D RAN and C RAN traffic. The MTN functionality is described from a network level viewpoint, taking into account the client characteristic information, client/server layer associations, networking topology, and layer network functionality that provide multiplexing, routing and supervision of the digital clients. MTN consists of two non recursive layers, the MTN Path layer, and the MTN Section layer. The MTN Path layer uses the MTN Section layer as its server layer. The MTN Path layer provides configurable connection-oriented connectivity. The server layer for the MTN section layer is provided by 50GBASE R, 100GBASE R, 200GBASE R, 400GBASE R Ethernet interfaces.