Dependency Analysis System to Narrow Down Missettings in SDN Construction Exercises Using Trema

Software defined networking (SDN) has been popular for research and innovation.Universities and research labs are the basic points for innovation because innovation by academia and research organizations can accelerate the rate of change in industries.SDN construction exercises have been developed in e-Learning.When performing network construction exercises, novice learners cannot understand the behavior of their network and fail to satisfy the requirements for the network reachability of communication data.In this system, learners construct SDN with Trema as exercises.A communication protocol OpenFlow is used for communication between controllers and switches.Here, some learners cannot find their bugs from their settings due to the following reasons such as (1) ping cannot find delivery routes including switches, (2) switches have no function to log rules used for choosing output ports for packets and (3) Trema cannot find execution statements used for setting rules to switches.To satisfy these problems, the system will provide clues for learners in visual way so that they can narrow down executed statements that cause incorrect communication.