The traditional ADM or DXC will be substituted by a new kind of network element(NE) in network node. This paper introduces the primary function of SDH NE and its atomic function structure.

• 现代传输网节点将由功能更强的 SDH网元取代传统的 ADM或 DXC,文章介绍了SDH网元的主要功能及设备的原子功能构成