Abstract
With the cloud system becomes the trend of internet, SDN networks are also growing.But there are still some weak points in SDN.Path selection is one of them.I use some simple commands to implement a runnable PCE program, and test this program in both cloud and simulative environment.I decide two experiment for testing:1.Testing the feasibility of functions in the PCE program architecture in real cloud environment.2.Testing the optimizations between SDN with PCE and SDN without PCE in simulative environment.