The highly dynamic nature of the current network traffics makes the network managers to exploit the flexibility of the state-of-the-art paradigm called SDN. In this way, there has been an increasing interest in hybrid networks of SDN-MPLS. In this paper, a new traffic engineering architecture for SDN-MPLS network is proposed. To this end, OpenFlow-enabled switches are applied over the edge of the network to improve flow-level management flexibility while MPLS routers are considered as the core of the network to make the scheme applicable for existing MPLS networks. The proposed scheme re-assigns flows to the Label-Switched Paths (LSPs) to highly utilize the network resources. In the cases that the flow-level re-routing is insufficient, the proposed scheme re-computes and re-creates the undergoing LSPs. To this end, we mathematically formulate two optimization problems, ie, i) flow re-routing and ii) LSP re-creation, and propose a heuristic algorithm to improve the performance of the scheme. Our experimental results show the efficiency of the proposed hybrid SDN-MPLS architecture in traffic engineering superiors traditionally deployed MPLS networks. KEYWORDS hybrid networks, MPLS, OpenFlow, PCE/PCEP, SDN, software defined WAN 1 INTRODUCTION Service providers around the world have large investments in highly sophisticated and feature-rich MPLS network infrastructures for providing services to their customers. These infrastructures are built on traditional network equipment (combined data plane and control plane), which are costly to scale, complex to manage, and time consuming to reconfigure. Network Function Virtualization (NFV), cloud computing, and the proliferation of connected devices are leading to exponentially increasing traffic and significant fluctuations in usage patterns. These reasons make network operators to move to agile architectures that support dynamic reconfiguration of both services and the network infrastructures. 1 For service providers, these capabilities provide new revenues, reduce time to market, increase new service uptake, and enhance their ability to meaningfully differentiate their offerings. 2The state-of-the-art paradigm called SDN 3 along with the OpenFlow protocol 4 provides lots of new traffic management features. 5 This makes it a proper and highly adopted technology for data center networks. One of the most important benefits of employing OpenFlow is its ability to route/re-route the traffic flows based on the network traffic pattern. In other words, it optimally routes/re-routes the traffic in flow level granularity.Therefore, there are lots of novel works that focus on traffic engineering in pure OpenFlow networks. 6-11 However, migration from carrier networks that are mostly MPLS-based to OF-based network is challenging and highly expensive.To circumvent the aforementioned challenges, we propose a novel traffic engineering architecture in which the integration of OpenFlow and traditional MPLS is adopted. This traffic engineering architecture is motivated by scenarios where S...