Applying router virtualization technology into SDN can not only forward traditional telecom traffic in SDN but also solve the problem of insufficient support of current SDN in fields of routing functions.In SDN controller

we can extend south interface to manage and control virtual router

and convert flow table and route table.Then we can control the data forwarding function of virtual router or Openflow switch.This method can make up the deficiencies of routing function in the current SDN controller

and achieve compatibility forwarding function of SDN traffic and traditional telecommunications traffic.This paper proposes a designing method and system of SDN platform based on the study of forwarding function of virtual router and SDN controller

which can realize basic routing functions.The system analysis result shows that the platform has features of excellent versatility

flexibility

and simple combining with cloud computing technologies.