# Video Streaming Adaptive QoS Routing with Resource Reservation (VQoSRR) Model for SDN Networks
## 1 Introduction
In recent years, the emergence of software defined networking architecture has allowed for innovative approaches in networking. With SDN, the control of the network is decoupled from the forwarding devices, enabling more flexible network management and programmability. SDN controllers use the OpenFlow protocols to gather information about the network topology and its states in order to support the controlling functionality. In contrast to link-state protocols, using a high specification controller to collect the updates of the data plane state can reduce the communication overhead on all forwarding devices due to the load of the flooding process used in the exchange of the link-state. Furthermore, the controller awareness of states can facilitate controlling the frequency of the emission of updates. In addition, the global view of resource availability enables traffic flows to be rerouted dynamically to ensure efficient resource utilization. The main contribution of this paper is to propose a video streaming adaptive QoS-based routing and resource reservation (VQoSRR) model for SDN networks. It investigates the QoS-based routing and resource reservation and shows how their combination could achieve overall enhancement in the QoS and QoE of video streaming. The model differentiates video traffic based on the QoE parameters of the video resolution, and this will directly reflect the impact of the QoS improvement on the user experience. Many approaches have already been proposed to achieve video streaming QoS in SDN, some of which use QoS-based routing, while others focus on resource reservation, we discuss their relationship to our proposed VQoSRR in Section 2. We designed VQoSRR to perform QoS-based routing within a single administrative domain (intra-domain) but not across inter-domain networks. In addition, we focused on using the QoS metrics that can solve the QoE problems at the network level, not at the video application level. Our integration of resource reservation mechanisms with QBR can provide adequate control over the route and resources, but this comes at the cost of extra setup time, even though, generally, the QoS will be more enhanced. It would be interesting to consider new parameters like scalability to address the issues of an increased number of users and videos. However, this parameter is not within the scope of this paper. We argue that our approach provides several advantages:  
* Combining per-flow QoS routing with resource reservation is minimizing the packet loss and latency for QoS flows and non-QoS flows, firstly, by guarantees that each flow type uses different routing paths, and secondly, by guaranteeing effective bandwidth allocation for QoS flows. * The differentiation of traffic based on QoE parameters (as video resolution); this implies the effect of QoS directly reflected to the end-user impressions. * The proposed framework reduces the overhead of obtaining network status by pre-computing of alternative paths. In this work, we extend the work presented in [7], which proposed a QoS-based routing algorithm (two lowest loss widest paths algorithm (TwoLLWPs)). This paper modified the QoS-based routing model to incorporate resource reservations and add new routing functionalities. This paper describes the experience and results of identifying an SDN network architecture that can provide QoE for video end-users by selecting routing paths based on several individual QoS metrics and reserving network resources for those routing paths. The key contributions of this study are summarized below:  
* We design a management system that monitors and collects performance information. * We develop QBR algorithms for path selection, rerouting traffic to an alternative path, and installing routing paths based on video streaming QoE requirements. * We define a higher-level reservation control strategy to enable administrating of allocating bandwidth for the different flows according to their requirements.