The dynamic establishment and removal of an end-to-end light-path
consume a lot of time which are also the main burden of control plane
in optical transport networks. With the frequent arrival and departure
of services, the control plane needs to handle a large number of
control and management messages to conduct path computation, resource
reservation and cross connection configuration. This draft proposes a
novel routing mechanism based on Path Table for software-defined
optical transport networks (SD-OTN). The Path Table reserves partial
activated established light-paths that can be directly used by
subsequent requests for subsequent services. This new routing
mechanism can reduce the network load and save routing time for some
services.