© December 2019 | IJIRT | Volume 6 Issue 7 | ISSN: 2349-6002 IJIRT 148857 INTERNATIONAL JOURNAL OF INNOVATIVE RESEARCH IN TECHNOLOGY 121 Traffic Engineering in Software Defined Network (SDN) R.Jothi Bhanu 1 , Dr.T.Vairam 2 1 PG Student, Department of Information Technology, PSG College of Technology, Coimbatore, Tamil Nadu, 641004, India 2 Assistant Professor [Sl.Gr], Department of Information Technology, PSG College of Technology, Coimbatore, Tamil Nadu, 641004, India Abstract- An important technique to optimize a network and improving network stability is traffic engineering. With the growing demand for traffic, traffic engineering can reduce service deterioration and network failure. Allow networks to adapt to changing traffic conditions, the research community proposed several traffic engineering techniques to traditional network architecture. However, the traditional network architecture is difficult to manage. Software Defined Networks (SDN) is a new network model that decouples the control and data layers of network devices. It promises to simplify network administration, introduce network programming capacity and provide an overview the state of the network. To exploit the potential of SDN, new traffic engineering methods are needed. This article provides an overview of state of the art in traffic engineering. It focuses on some of Traffic engineering methods for traditional network architecture and lessons learned. Better traffic engineering methods for SDN based networks. This article also examines the challenges and future of research. I.INTRODUCTION An SDN Controller is an application in Software Defined Networking architecture that manages flow control for improved network management and application performance. The SDN Controller platform typically runs on a server and uses protocols to tell switches where to send packets. SDN controllers direct traffic according to forwarding policies that a network operator can manual configurations for individual network devices. By taking the control plane off of the network hardware and running it instead as software, the centralized controller facilities automated network management and makes it easier to integrate and administer business applications. In effect, the SDN Controller serves as a sort of operating system for the network. The controller is the core of a Software-defined network. It resides between network devices at one end of the network and applications at the other end. Any communication between applications and network devices must go through the controller. The controller communicates with applications – such as firewalls or load balancers –via northbound interfaces. The Open Networking Foundation (ONF) created a working group in focused specifically on northbound APIs and their development. Traffic engineering is the solution that network providers use when they need to optimize their existing IP/MLPs networks and provide more services to customers. Most IP networks use hop-by-hop-based routing, where the shortest path between a source and destination is used to route packets, even when the shortest path is not the best-performing one. Traffic engineering allows the provider to ignore the shortest-path rule by sending traffic over longer but less congested links. This helps alleviate network congestion and enables the network provider to maximize the use of the existing network infrastructure. II. THE TRAFFIC ENGINEERING EVOLUTION Network engineers have used traffic for a long time. The early implementations used an offline model, which involved the current network technology and traffic demand matrix into a planning tool that calculated the best path using optimization algorithms. This method while workable could not handle the network changes efficiently enough because of several challenges. The biggest issue came from having to add the network topology into the planning tool. This is easy when there are only a handful of routers, but its major challenge when the network has several hundreds or thousands of routers.