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Inbound load balancing plays an important role in improving the quality of experience for enterprise networks. Traditional traffic engineering approaches fail to achieve fine-grained inbound load balancing because they have limited capability of obtaining detailed network status and lack flexibility for traffic flow scheduling. In this paper, we adopt OpenFlow to achieve effective inbound load balancing. The potential of implementing OpenFlow in an enterprise network is explored to schedule traffic among different inbound links. We also investigate how to avoid frequent scheduling and the feasibility when applying this approach in real networks. In order to evaluate the proposed approach, an emulation platform is developed based on Mininet, POX and Open vSwitch. Emulation is conducted based on an actual network topology. Emulation results verify that the proposed approach is able to achieve effective load balancing for enterprise networks and avoid unnecessary flow scheduling.

Changing the whole network into a software defined network (SDN) is impractical due to high replacement cost. Therefore, there exist SDN hybrid networks, where SDN switches and legacy switches coexist at the same time. In this paper, we propose an SDN hybrid network architecture which can discover existence of legacy switches by using the Spanning Tree Protocol and thus have a global view of the SDN hybrid network. We also enable OpenFlow switches to cooperate with legacy switches by using the Learning Bridge Protocol without requiring any modification on legacy switches. By utilizing the characteristics of SDN, SDN applications can dynamically find routing paths according to pre-defined QoS requirements and current network status. We also propose a simulated annealing based QoS-aware routing (SAQR) algorithm which can adaptively adjust weights of delay, loss rate and bandwidth requirements in a cost function to find the best fit path according to QoS requirements. We evaluate the proposed SAQR in a simulated SDN hybrid network which runs applications with different QoS requirements. Simulation results show that the SAQR performs better than related work MINA in terms of the fitness ratios of delay, loss rate and bandwidth, with 88%, 90.8% and 86.5% of flows meeting their respective QoS requirements, in contrast to MINA, with only 63%, 82.4% and 87.5% of flows meeting their respective QoS requirements.

Software Defined Networking (SDN) substrates are basic enabler for the network virtualization. They provide many opportunities but also require new solutions for well known legacy mechanisms. Thus, in this paper we present an innovative network monitoring tool which is able to operate with the usual available OpenFlow controllers. The presented tool extends the controller monitoring capabilities by providing utilization charts and statistics up to a flow level. In order to present the feature set, the tools architecture and implementation will be introduced. Further, an evaluation on a virtualized Mininet network using Open vSwitch is presented as well as an evaluation on our SDN research cluster with a typical data center fat tree topology composed out of NEC IP 8800 switches.

Software Defined Networks (SDN) is a novel model for networking that is currently becoming an interesting area for research and industry organizations which makes networks more manageable and customizable. In this paper, we investigated OpenFlow Discovery Protocol v.2 (OFDP v2) and compare it with standard OFDP protocol. We also intend to study OFDP v2 behavior and how it works in term of packet retransmission between SDN controller and SDN switches. We mean to show how OFDP v2 works from different perspective. Our experiments show that using OFDPv.2B protocol requires at least one retransmission per each packet which the controller sends out. However, OFDPv.2 still shows better results when it is compared with standard OFDP protocol in term of reducing the number of Packet_OUT messages.

In recent years, a Cloud computing system has been popularly used. Among them, a hybrid Cloud is focused, which combined a public Cloud operated by service providers and a private Cloud constructed inside a company. Because a private Cloud is considered to be secure and a public Cloud is scalable, it is possible to build a Cloud computing system that works effectively by combining the both types of Clouds. However, when a big disaster occurrs, huge volume of data is produced by monitoring censors and users, and flowed into such an information infrastructure. In addition, enormous number of people access to the system in such a case, thus a load of the system becomes extremely high in a short time. Therefore, it is important to change an environment dynamically among inter-Cloud and intra-Cloud to deal with the load. In this paper, bursty increasing load is predicted based on Earthquake Early Warning (EEW), and a speculative control is performed in a short time between a time of occurrence of an earthquake and a time when the system is heavily loaded actually. In addition, network traffic is controlled to give a higher priority to important data replication. The system is constructed on a Cloud computing platform using public domain software, OpenStack in this experiment. Network traffic of the system is controlled by Software Defined Network (SDN), which is controlled by the OpenFlow protocol. As a result of an evaluation, our proposed system works fine and achieves good performance.

The rapid proliferation of the Internet of Things (IoT) has led to growth in the ad-hoc networking scenario. With the recent upcoming technologies of network programmability like SDN may be effectively integrated to create a communication platform. In this work, we present the details of our preliminary study of how to determine the effectiveness of an approach to build a cluster network using Software-Defined Networking (SDN). We will provide an overview of optimum path routing protocol with cluster interaction. Our proposed scheme is a starting point for some experiments providing perspective over SDN deployment in a cluster environment for IoT. With this aim in mind, we propose a routing protocol that manages routing tasks over Cluster-SDN. By using network virtualization and OpenFlow technologies to generate virtual nodes, we simulate a prototype system controlled by SDN. Our designed testbed, is a real openflow protocol evaluation environment comprising networks and applications, which provide flexible control of framework support for large scale experiments.

Many network device vendors are providing a vendor specific VLAN based access solutions for WLAN clients. This applications allows network operators to specify WLAN devices which automatically fall into their department specific networks ans allows them to access their local resources like e.g. printers. The configuration of these VLAN mappings is usually manufacturer specific and depends also on the local VLAN policies. However, the presented OpenFlow approach on the other hand presents a solution to encapsulate this functionality as network application. Thus, an architecture, implementation, and evaluation is presented in order to demonstrate that this particular functionality can be easily realized in an OpenFlow network application.

Long-lived flows termed as elephant flows normally transport large volumes of data in enterprise networks, particularly data center networks. These flows tend to consume a lot of bandwidth and fill up network buffers end-to-end. This causes non-trivial delays for short-lived flows referred to as mice flows which are usually delay-sensitive. Therefore, identifying and handling elephant flows is important for QoS provisioning. In this paper, we present a framework for real-time detection and visualization of elephant flows in SDN-based networks using sFlow. Using our proposed framework, network operators can examine elephant flows through each switch by double-clicking the switch node in the topology visualization UI. Although not in the scope of this paper, but in order to meet traffic engineering requirements, the elephant flows detected and visualized by our proposed framework can be reprioritized, re-scheduled, or routed via dedicated high speed links. We evaluate the proposed framework by using a physical SDN testbed as well as a Mininet-based testbed.

Since the Internet was defined by TCP/IP suite, it cannot accommodate today's large amount of devices and huge amount of internet traffic which were not considered when it was invented. Also current routing is wasting network resource by utilizing link unfairly. One of the approaches to solve these problems is a centralized routing architecture such as SDN. In this paper, we proposed “Automatic Re-routing with Loss Detection” architecture. Packet loss is detected with queue stat message of Openflow protocol, then Re-routing module tries to find bypass and applies to flow tables. Through an emulation with actual controller and virtual network, we showed that proposed scheme reduced overall average loss rate and improved loss fairness over the net-work by standardizing loss rate of each traffic.

Software defined networking (SDN) is a recent networking architectural framework which aims to provide the complete separation of data plane and control plane. Openflow is a well-known architecture that facilitates SDN. The core idea of Openflow is to control the switch or router through programming from the centralized controller. The connection reliability is a major concern for the network service providers. The analysis of network resiliency is required for this new paradigm. The resiliency is the network's ability to survive against attacks and other component failures. This paper focuses on a comparison of different data forwarding algorithms currently supported by the POX standards for protection and restoration. Understanding existing approaches or standards in SDN plays a crucial role in network resiliency or protection and restoration. We also provide the extension of one of the components in POX for improvement. The restoration scheme in the current POX components as well as in the modified component is evaluated and compared.

Since the cloud paradigm becomes more and more popular for the dynamic resources allocation, new techniques and performance improvements for scalability as well as new cloud services on all three layers of the cloud stack were developed. Furthermore, another well covered topic is cloud federation concerning processing power and strength. However, the flexibility of the cloud is limited in terms of network services and federated networking between autonomous cloud data-center. With the promising opportunities of Software Defined Networking (SDN), this gap can be closed and enables cloud environments to establish networking federations between autonomous data-centers and virtual network partitioning in a single cloud infrastructure. In this paper we are introducing and describing an architectural approach for a generic layered model and API based software architecture to orchestrate and federate heterogeneous networks. In particular, we present an architecture that enables Quality of Service (QoS) aware configurations of network resources in a cloud infrastructure of one data-center and federated networking between different SDN based cloud networks over and above the data-center network edge. Furthermore, this architecture uses a Service Level Agreement (SLA) protocol and language to expose Key Performance Indicators (KPI) and to negotiate appropriated QoS constrains which are applied to the virtually sliced underlying network substrate. In this way, capabilities of the orchestration and the current utilization of the network are building the foundation for dynamic negotiated SLAs and the within guaranteed QoS of network resources. The approach presented in this paper will change today's IT landscape and allows every organization to purchase required network characteristics on demand.

Software defined networking becomes more and more popular in the networking community, but is still missing its triumphal procession into existing networks. Especially data-centers could benefit from this evolutionary network paradigm and get rid of many legacy parts with are still blocking the evolution how their networks are working in general. In this paper we will present an approach, use-case and performance evaluation as well, for the integration of software defined networking applications in data-centers. This approach addresses a sub topic or more precisely a single software defined networking application for enhancing inter rack communication by involving the top-of-rack and aggregation switches in a common fat-tree network topology. The basic aim is to provide some sort of load distribution mechanism on the afore mentioned network layers by using a flow based load sharing procedure with layer two multi-path. The evaluation will show that this is increasing the throughput in a rack-to-rack data exchange scenario.

With the emergence of inexpensive network components and high-speed network services, a variety of network-capable electronic devices have become available. Typical examples of such devices include printers, network access storage (NAS), and video recorders. Because software on these devices is not always kept up-to-date, the devices are susceptible to intra-local- area-network (LAN) attacks. In this paper, a novel network system architecture is proposed to protect network devices from intra-LAN attacks by dynamically isolating infected devices with OpenFlow. Preliminary evaluation results demonstrate that the architecture is effective in actual LAN environments.