Currently the all-IP trend of telecommunication service and evolution of IP network have brought huge challenge for transport network. The FMC trend and deployment of cluster router require the transport network to have multi-service bearer capability and larger bandwidth as well as the capability to adapt to MESH typology structure. Meanwhile, viewing from the course of technological progress, domestic and overseas mainstream operators have more and higher requirements such as IP-based, intelligent, green and eco-friendly for WDM technology after point-to-point WDM and OTN. Therefore, iOTN solution integrated with OTN, control plane, λ-level and sub-λ-level cross-connection and L2 switching technology has become the development direction of next-generation optical network.