Performance Study of a Software Defined Network Emulator Jose M. Jimenez, Oscar Romero, Albert Rego, Avinash Dilendra, Jaime Lloret Universidad Politécnica de Valencia Camino Vera s/n 46022, Valencia (Spain) email: jojiher@dcom.upv.es, oromero@dcom.upv.es, alrema91@gmail.com, avinash.dilendra@gmail.com, jlloret@dcom.upv.es Abstract—Generally, network researchers use applications that allow them to emulate or simulate networks. It is desired to obtain very close results between the ones given in a virtual and the ones obtained when the real network hardware is implemented. In this paper, we compare the experimental results obtained when a virtual network is generated by using Mininet versus a real implemented network. We have compared them varying the Maximum Transmission Unit (MTU) on Internet Protocol version 4 (IPv4) and Internet Protocol version 6 (IPv6) packets. Ethernet, Fiber Distributed Data Interface (FDDI), and Wireless Local Area Network 802.11 (WLAN 802.11) MTUs have been used in our experimental tests. Keywords- SDN; OpenFlow; Mininet; MTU; virtualization; bandwidth; jitter. I. INTRODUCTION In the field of computer networks, the researches usually use programs that allow us to emulate or simulate networks. This is because, in most cases, we do not have the necessary devices needed to create complex networks. There are emulators and simulators as Omnet++ [1], OPNET [2], NS- 2 [3], NS-3 [4] Netsim [5], GNS3 [6], etc. that are frequently used to create computer networks. Deployment of network is very quick in virtual environment, even if it is needed a large number of resources, which is always practically almost impossible to implement with real hardware. Problem solving or troubleshooting capability is still easier than real implementations. Note that a network researcher has to keep in mind that the results obtained from a virtual network should be similar from those obtained by the real hardware network. If there is a significant difference between results of virtual network and real network, then the research work should not be taken into consideration. As a network test bed gives almost the same results than the real implemented network, then it saves a large amount of time, complexity and a lot of resources. In general, network devices perform the transport and the control function. But, configuring a great amount of devices and changing the configuration efficiently to work properly, it means a big challenge for networking professionals. Today's, computer network world is able to offer a large amount of functionalities suited to the requirements of users. A new technology, named Software Defined Networking (SDN) [7] appears to increase the efficiency and reduce the cost of network configuration. Figure 1 shows the components of SDN in a layered structure. The first layer consists of some frequently used tools of monitoring and depuration. The tool “Oftrace” is used for analyzing and parsing Openflow message from network dump. “Oftrace” provides a library which analyzes and parses the message from TCP dump or Wireshark [8]. Loops or cyclic path can cause critical problems in SDN. “Oflops” is a tool to catch the loop mechanism in the software defined networks. It mentions the data packets in the loop which are not able to leave the network [9]. “Openseer” is a CGI script which helps to plot that data effectively in SDN [10]. In Controllers Layer there are few controllers which are used in SDN. More often, controllers are called the Brain of Network which controls and manages the software defined network. Floodlight, Open Daylight, Beacon, Nox are among the frequently used controllers in SDN [11]. Flow Visor ensures that multiple isolated logical networks can share the same topology and hardware resources of a network. It places as a transparent proxy between OpenFlow switches and OpenFlow controllers. The isolated logical network is named slice of the network and flow visor is named slicing software in SDN [12]. In SDN environment, OpenFlow switches are used to forward the packets. OpenFlow switches are either a software program or a hardware device which is compatible to OpenFlow protocols. Some of the commercial switches are available in market like HP, Nec, Juniper, etc. [13]. Mininet is used to create realistic virtual network within seconds on a single machine that could be able to run real kernel, switch and application code [14]. There are few emulators and simulators which are frequently used to run and control the technology SDN from a single screen, like NS-3, Estinet 9.0 [15], OmNet ++, Mininet, etc. In this paper, we show the comparison among the obtained results from the virtual networks and from the real implemented networks. With the assessment of these results we are able to find the significant differences, which may be very useful for the researchers who all are performing their research work in Networking Industry. 17 Copyright (c) IARIA, 2016. ISBN: 978-1-61208-475-6 ICIMP 2016 : The Eleventh International Conference on Internet Monitoring and Protection