This study proposes a Software-Defined Networking (SDN) architecture to help cloud customers receive highly efficient services in a heterogeneous cloud serving system. An application called SDNBroker is designed herein and superposed on the SDN controller by Northbound Application Programmatic Interfaces (Northbound API). When a cloud customer requests a service, the proposed SDNBroker schedules heterogeneous cloud serving resources using the single-constraint Lagrange Multiplier method and optimizes network routing using Dijkstra's algorithm. Three heterogeneous cloud-serving systems and three kind applications were used to validate the proposed SDNBroker. The proposed SDNBroker system is more efficient than the specified cloud serving system (NonSDNBroker system with single path) by 6%∼18%. In addition, the network link utilization of the proposed route procedure is increased by about 6.4%.