Performances of OpenFlow-Based Software- Defined Networks: An overview <s> C. Simulation and Emulation Tools <s> Mininet is a system for rapidly prototyping large networks on the constrained resources of a single laptop. The lightweight approach of using OS-level virtualization features, including processes and network namespaces, allows it to scale to hundreds of nodes. Experiences with our initial implementation suggest that the ability to run, poke, and debug in real time represents a qualitative change in workflow. We share supporting case studies culled from over 100 users, at 18 institutions, who have developed Software-Defined Networks (SDN). Ultimately, we think the greatest value of Mininet will be supporting collaborative network research, by enabling self-contained SDN prototypes which anyone with a PC can download, run, evaluate, explore, tweak, and build upon. <s> BIB001 </s> Performances of OpenFlow-Based Software- Defined Networks: An overview <s> C. Simulation and Emulation Tools <s> Recent efforts in software-defined networks, such as OpenFlow, give unprecedented access into the forwarding plane of networking equipment. When building a network based on OpenFlow however, one must take into account the performance characteristics of particular OpenFlow switch implementations. In this paper, we present OFLOPS, an open and generic software framework that permits the development of tests for OpenFlow-enabled switches, that measure the capabilities and bottlenecks between the forwarding engine of the switch and the remote control application. OFLOPS combines hardware instrumentation with an extensible software framework. ::: ::: We use OFLOPS to evaluate current OpenFlow switch implementations and make the following observations: (i) The switching performance of flows depends on applied actions and firmware. (ii) Current OpenFlow implementations differ substantially in flow updating rates as well as traffic monitoring capabilities. (iii) Accurate OpenFlow command completion can be observed only through the data plane. These observations are crucial for understanding the applicability of Open- Flow in the context of specific use-cases, which have requirements in terms of forwarding table consistency, flow setup latency, flow space granularity, packet modification types, and/or traffic monitoring abilities. <s> BIB002 </s> Performances of OpenFlow-Based Software- Defined Networks: An overview <s> C. Simulation and Emulation Tools <s> Most network management tasks in software-defined networks (SDN) involve two stages: measurement and control. While many efforts have been focused on network control APIs for SDN, little attention goes into measurement. The key challenge of designing a new measurement API is to strike a careful balance between generality (supporting a wide variety of measurement tasks) and efficiency (enabling high link speed and low cost). We propose a software defined traffic measurement architecture OpenSketch, which separates the measurement data plane from the control plane. In the data plane, OpenSketch provides a simple three-stage pipeline (hashing, filtering, and counting), which can be implemented with commodity switch components and support many measurement tasks. In the control plane, OpenSketch provides a measurement library that automatically configures the pipeline and allocates resources for different measurement tasks. Our evaluations of real-world packet traces, our prototype on NetFPGA, and the implementation of five measurement tasks on top of OpenSketch, demonstrate that OpenSketch is general, efficient and easily programmable. <s> BIB003
Several simulation and emulation tools have been developed to implement OpenFlow-based networks on a single machine and to test new applications. For example, Mininet BIB001 an SDN emulation environment developed by the Stanford University, it can be used to deploy a virtual network and estimate performance metrics for various network topologies and sizes. Another option is to use the NS3 [34] network simulator that supports OpenFlow within its environment. For performance analysis of OpenFlow switches, an open framework called OFLOPS BIB002 has been developed. It permits the development of tests for OpenFlow switches such as CPU utilization, packet counters, then it determines the bottlenecks between the switch and the remote control application. On the other hand, for performance analysis of controllers, an OpenFlow controller benchmarker called Cbench  , has also been developed. Cbench emulates a bunch of Open-Flow switches connect to a controller then computes the performance metrics like throughput, response time, and latency of an SDN controller. Another tool proposes a software-defined traffic measurement architecture called OpenSketch BIB003 , it collects measurement information from data plane and the control plane. In the data plane, OpenSketch provides a simple three-stage pipeline (hashing, filtering, and counting). However, in the control plane, OpenSketch provides a measurement library that automatically configures the pipeline and it allocates resources for different measurement task.