In order to provide services for government and enterprise customers with OTN

and quickly establish links end to end

openning up different OTN systems on the network level is required.Based on the OTN interface structure proposed by ITU-T G.709

this paper analyzes the docking schemes among OTN systems of different management domains

including interface selection

connection of network managements

protection of docking networks and other issues

meanwhile putting forward implementation suggestions combined with network in practical.