A method and a software defined network (SDN) controller for chaining applications in a SDN. A service data table is created in the SDN controller. In the service data table a plurality of applications are associated with a plurality of application types. Furthermore, at least one service chain is created in the SDN controller. The at least one service chain defines an order of application types running on the SDN controller. At least one application is registered to the service chain based on its application type as associated with the application in the service data table.