When Should I Use Network Emulation?

The design and development of a complex system requires an adequate methodology and efficient instrumental support in order to early detect and correct anomalies in the functional and non-functional properties of the tested protocols. Among the various tools used to provide experimental support for such developments, network emulation relies on real-time production of impairments on real traffic according to a communication model, either realistically or not. This paper aims at simply presenting to newcomers in network emulation (students, engineers, ...) basic principles and practices illustrated with a few commonly used tools. The motivation behind is to fill a gap in terms of introductory and pragmatic papers in this domain. The study particularly considers centralized approaches, allowing cheap and easy implementation in the context of research labs or industrial developments. In addition, an architectural model for emulation systems is proposed, defining three complementary levels, namely hardware, impairment and model levels. With the help of this architectural framework, various existing tools are situated and described. Various approaches for modeling the emulation actions are studied, such as impairment-based scenarios and virtual architectures, real-time discrete simulation and trace-based systems. Those modeling approaches are described and compared in terms of services and we study their ability to respond to various designer needs to assess when emulation is needed

Network emulation focusing on QoS-Oriented satellite communication

This chapter proposes network emulation basics and a complete case study of QoS-oriented Satellite Communication

Two-stage wireless network emulation

Testing and deploying mobile wireless networks and applications are very challenging tasks, due to the network size and administration as well as node mobility management. Well known simulation tools provide a more flexible environment but they do not run in real time and they rely on models of the developed system rather than on the system itself. Emulation is a hybrid approach allowing real application and traffic to be run over a simulated network, at the expense of accuracy when the number of nodes is too important. In this paper, emulation is split in two stages : first, the simulation of network conditions is precomputed so that it does not undergo real-time constraints that decrease its accuracy ; second, real applications and traffic are run on an emulation platform where the precomputed events are scheduled in soft real-time. This allows the use of accurate models for node mobility, radio signal propagation and communication stacks. An example shows that a simple situation can be simply tested with real applications and traffic while relying on accurate models. The consistency between the simulation results and the emulated conditions is also illustrated

W-NINE: a two-stage emulation platform for mobile and wireless systems

More and more applications and protocols are now running on wireless networks. Testing the implementation of such applications and protocols is a real challenge as the position of the mobile terminals and environmental effects strongly affect the overall performance. Network emulation is often perceived as a good trade-off between experiments on operational wireless networks and discrete-event simulations on Opnet or ns-2. However, ensuring repeatability and realism in network emulation while taking into account mobility in a wireless environment is very difficult. This paper proposes a network emulation platform, called W-NINE, based on off-line computations preceding online pattern-based traffic shaping. The underlying concepts of repeatability, dynamicity, accuracy and realism are defined in the emulation context. Two different simple case studies illustrate the validity of our approach with respect to these concepts

Toward Automating Web Protocol Configuration for a Programmable Logic Controller Emulator

Industrial Control Systems (ICS) remain vulnerable through attack vectors that exist within programmable logic controllers (PLC). PLC emulators used as honeypots can provide insight into these vulnerabilities. Honeypots can sometimes deter attackers from real devices and log activity. A variety of PLC emulators exist, but require manual figuration to change their PLC pro le. This limits their flexibility for deployment. An automated process for configuring PLC emulators can open the door for emulation of many types of PLCs. This study investigates the feasibility of creating such a process. The research creates an automated process for figuring the web protocols of a Koyo DirectLogic PLC. The figuration process is a software program that collects information about the PLC and creates a behavior pro le. A generic web server then references that pro le in order to respond properly to requests. To measure the ability of the process, the resulting emulator is evaluated based on response accuracy and timing accuracy. In addition, the figuration time of the process itself is measured. For the accuracy measurements a workload of 1000 GET requests are sent to the index.html page of the PLC, and then to the emulator. These requests are sent at two rates: Slow and PLC Break. The emulator responses are then compared to those of the PLC baseline. Results show that the process completes in 9.8 seconds, on average. The resulting emulator responds with 97.79% accuracy across all trials. It responds 1.3 times faster than the real PLC at the Slow response rate, and 1.4 times faster at the PLC Break rate. Results indicate that the automated process is able to create an emulator with an accuracy that is comparable to a manually figured emulator. This supports the hypothesis that creating an automated process for figuring a PLC emulator with a high level of accuracy is feasible

Emulation of Industrial Control Field Device Protocols

It has been shown that thousands of industrial control devices are exposed to the Internet, however, the extent and nature of attacks on such devices remains unknown. The first step to understanding security problems that face modern supervisory control and data acquisition (SCADA) and industrial controls networks is to understand the various attacks launched on Internet-connected field devices. This thesis describes the design and implementation of an industrial control emulator on a Gumstix single-board computer as a solution. This emulator acts as a decoy field device, or honeypot, intended to be probed and attacked via an Internet connection. Evaluation techniques are developed to assess the accuracy of the emulation implemented on the Gumstix and are compared against the implementation on a standard PC and the emulation target, a Koyo DirectLogic 405 programmable logic controller. The results show that both the Gumstix and PC emulator platforms are very accurate to the workloads presented. This suggests that a honeypot implemented on a Gumstix emulator and a standard PC are both suitable for applications in SCADA attack-landscape research

IREEL: remote experimentation with real protocols and applications over emulated network

This paper presents a novel e-learning platform called IREEL. IREEL is a virtual laboratory allowing students to drive experiments with real Internet applications and end-to-end protocols in the context of networking courses. This platform consists in a remote network emulator offering a set of predefined applications and protocol mechanisms. Experimenters configure and control the emulation and the end-systems behavior in order to perform tests, measurements and observations on protocols or applications operating under controlled specific networking conditions. A set of end-to-end mechanisms, mainly focusing on transport and application level protocols, are currently available. IREEL is scalable and easy to use thanks to an ergonomic web interface

Don't Repeat Yourself: Seamless Execution and Analysis of Extensive Network Experiments

This paper presents MACI, the first bespoke framework for the management, the scalable execution, and the interactive analysis of a large number of network experiments. Driven by the desire to avoid repetitive implementation of just a few scripts for the execution and analysis of experiments, MACI emerged as a generic framework for network experiments that significantly increases efficiency and ensures reproducibility. To this end, MACI incorporates and integrates established simulators and analysis tools to foster rapid but systematic network experiments. We found MACI indispensable in all phases of the research and development process of various communication systems, such as i) an extensive DASH video streaming study, ii) the systematic development and improvement of Multipath TCP schedulers, and iii) research on a distributed topology graph pattern matching algorithm. With this work, we make MACI publicly available to the research community to advance efficient and reproducible network experiments

Design of testbed and emulation tools

The research summarized was concerned with the design of testbed and emulation tools suitable to assist in projecting, with reasonable accuracy, the expected performance of highly concurrent computing systems on large, complete applications. Such testbed and emulation tools are intended for the eventual use of those exploring new concurrent system architectures and organizations, either as users or as designers of such systems. While a range of alternatives was considered, a software based set of hierarchical tools was chosen to provide maximum flexibility, to ease in moving to new computers as technology improves and to take advantage of the inherent reliability and availability of commercially available computing systems

Network Virtualization and Emulation using Docker, OpenvSwitch and Mininet-based Link Emulation

With the advent of virtualization and artificial intelligence, research on networked systems has progressed substantially. As the technology progresses, we expect a boom in not only the systems research but also in the network of systems domain. It is paramount that we understand and develop methodologies to connect and communicate among the plethora of devices and systems that exist today. One such area is mobile ad-hoc and space communication, which further complicates the task of networking due to myriad of environmental and physical conditions. Developing and testing such systems is an important step considering the large investment required to build such gigantic communication arrangements. We address two important aspects of network emulation in this work. We propose a network emulation framework, which emulates the functioning of a hierarchical software defined network. One such use-case is described using a mobile ad-hoc network (MANET) topology within a single system by leveraging contemporary network virtualization technologies. We present various aspects of the network, such as the dynamic communication in the software domain and provide a novel approach to build upon existing emulation techniques. The second part of the thesis presents a dynamic network link emulator. This emulator enables suitable link property re-configurations such as bandwidth, delay and packet loss for networked systems using simulation software. We characterize the results of tests for the link emulation using a hardware and software testbed. Through this thesis, we aim to make a small yet crucial contribution to the niche area of software defined networks