Today, cloud networking which is the ability to connect users with their cloud services and to interconnect these services in an inter-cloud approach, is one of the recent research areas within the cloud computing research communities. The main drawback of cloud networking consists in the lack of Quality of Service (QoS) guarantee and management in conformance with a corresponding Service Level Agreement. In this paper, a framework is proposed for resource allocation according to an end-to-end service level agreement established between a Cloud Service User and several Cloud Service Providers within a cloud networking environment. The paper focuses on QoS parameters for NaaS and IaaS services. In addition, several algorithms are proposed for the best Cloud Service Providers selection to allocate VMs and network resources within a Broker and a Federation based inter-cloud scenarios. The objective is to minimize the total cost while satisfying NaaS and IaaS QoS constraints. Moreover, the proposed cloud networking architecture is used to provide videoconferencing and intensive computing applications with QoS guarantee. The corresponding scenarios are simulated using an extended CloudSim toolkit. The results reveal a high scalability and good performances where the Broker architecture is the most interesting while ensuring QoS requirements.