THe nodes can be moved using the CTRL key. From the GUI the user needs to upload a topology(json file). This file generates a random layout (little bit hardcoded). The GUI stores the modified position of the nodes in a javascript session var (sessvars api). Help icon that informs about how move the nodes. Routes defined in tree; the GUI show the possible routes and the port-switch connection of these routes. COntroller show the list of switches connected. The topology file is only stored in the GUI. And is overwrited, but the possibility to remove a topology and load another is not enable yet. Some corrections reagrding to javascript. Bean, validator and controllerSpring modification in order to support the upload file function. Help image. Other css. Topoogy inside a div.