Software-Defined Networking (SDN) is an architectural approach that fulfils the requirement of high bandwidth and the dynamic nature of current applications. One of the key features of the SDN architecture is the separation of the control logic from data plane devices. This key feature introduces a new type of control traffic in the SDN architecture, which opens the space for new vulnerabilities to SDN-based networks. In this paper, we first present an attack model to exploit the control channel of the SDN architecture. We then experimentally evaluate the impact of the attack on the end-users of the SDN-based network using our physical experimental testbed. Our experimental results clearly show that the control channel DoS attack has a major impact on the end-users of the SDN-based networks.