SCOR: Software-defined Constrained Optimal Routing Platform for SDN

A Software-defined Constrained Optimal Routing (SCOR) platform is introduced as a Northbound interface in SDN architecture. It is based on constraint programming techniques and is implemented in MiniZinc modelling language. Using constraint programming techniques in this Northbound interface has created an efficient tool for implementing complex Quality of Service routing applications in a few lines of code. The code includes only the problem statement and the solution is found by a general solver program. A routing framework is introduced based on SDN's architecture model which uses SCOR as its Northbound interface and an upper layer of applications implemented in SCOR. Performance of a few implemented routing applications are evaluated in different network topologies, network sizes and various number of concurrent flows.Comment: 19 pages, 11 figures, 11 algorithms, 3 table

The Correlation between Islamic Lifestyle and Pregnancy-Specific Stress: A Cross-Sectional, Correlational Study

BACKGROUND: Pregnancy is associated with great psychological, emotional and physical stress. In addition to undergoing hormonal changes, pregnant women experience a change in their attitude toward life and learn to re-assess their skills and lifestyle. Lifestyle, in general, and Islamic lifestyle, in particular, is concerned with the different psychological, social and physical aspects of the individual’s life.AIM: This study was conducted to evaluate the correlation between Islamic lifestyle and pregnancy-specific stress in pregnant women.MATERIAL AND METHODS: This cross-sectional, correlational study was conducted on 300 pregnant women presenting to prenatal care clinics. Data were collected using a demographic, the Islamic lifestyle and the pregnancy-related stress questionnaires.RESULTS: The results showed a statistically significant negative correlation (r = -0.284) between Islamic lifestyle and pregnancy-specific stress (P < 0.01). The stepwise regression showed that the mean score obtained in the pregnancy-related stress questionnaire decreased by 0.75 per year of marriage and by 0.14 per point in the Islamic lifestyle questionnaire.CONCLUSION: There was a significant negative correlation between Islamic lifestyle and pregnancy-specific stress. Training mothers, raising their awareness and encouraging them to adopt an Islamic lifestyle may play a significant role in controlling pregnancy-specific stress

R2Lab Testbed Evaluation for Wireless Mesh Network Experiments

International audienceWe have provided critical evaluations of new potential testbeds for the evaluation of SDN-based WMNs. We evaluated the R2Lab wireless testbed platform at INRIA Sophia-Antipolis, France. This testbed has 37 customisable wireless devices in an anechoic chamber for reproducible research in wireless WiFi and 4G/5G networks. Our work presents the first initial evaluation of the testbed for wireless multi-hop experiments , using traditional WMN routing protocols. Our results demonstrate the potential for SDN experiments. We believe this is an important contribution in its own right, since experimental validation is a key research methodology in this context, and trust in the validity of experimental results is absolutely critical

A new QoS routing northbound interface for SDN

In this paper, we introduce SCOR (Software-defined Constrained Optimal Routing), a new Software Defined Networking (SDN) Northbound Interface for QoS routing and traffic engineering. SCOR is based on constraint-programming techniques and is implemented in the MiniZinc modelling language. It provides a powerful, high-level abstraction layer, consisting of 10 basic constraint-programming predicates. A key feature of SCOR is that it is declarative, where only the constraints and utility function of the routing problem need to be expressed, and the complexity of solving the problem is hidden from the user, and handled by a powerful generic solver. We show that the interface (set of predicates) of SCOR is sufficiently expressive to handle all the known and relevant QoS routing problems. We further demonstrate the practicality and scalability of the approach via a number of example scenarios, with varying network topologies, network sizes and number of flows

The (In)security of topology discovery in software defined networks

Topology Discovery is an essential service in Software Defined Networks (SDN). Most SDN controllers use a de-facto standard topology discovery mechanism based on Open-Flow to identify active links in the network. This paper discusses the security, or rather lack thereof, of the current SDN topology discovery mechanism, and its vulnerability to link spoofing attacks. The feasibility and impact of the attacks are verified and demonstrated via experiments. The paper presents and evaluates a countermeasure based on HMAC authentication

SCOR: constraint programming based northbound interface for SDN

In this paper, we introduce SCOR (Software-defined Constrained Optimal Routing), a new SDN Northbound Interface for QoS routing and traffic engineering. SCOR is based on constraint programming techniques and is implemented in the MiniZinc modelling language. It provides a powerful, high level abstraction, consisting of 9 basic constraint programming predicates. A key feature of SCOR is that it is declarative, where only the constraints and utility function of the routing problem need to be expressed, and the complexity of solving the problem is hidden from the user, and handled by a powerful generic solver. We show that the interface (set of predicates) of SCOR is sufficiently expressive to handle all the known and relevant QoS routing problems. We further demonstrate the practicality and scalability of the approach via a number of example scenarios, with varying network topologies, network sizes and number of flows

Evaluation of Mininet-WiFi integration via ns-3

Mininet is a Linux-based network emulator that is particularly widely used for Software Defined Network experiments, due to its in-built support for OpenFlow switches. However, Mininet currently lacks support for wireless links. A recent work has addressed this limitation by using the real-time feature of ns-3 to integrate the IEEE 802.11 channel emulation feature with Mininet, which we refer to as Mininet-ns3-WiFi. While this approach has great potential to serve as an experimental platform, in particular for Software Defined Wireless Networks, it has not been extensively evaluated in terms of experiment result accuracy and fidelity. This is critical for any system that integrates simulation with real-time components. In this paper, we present a detailed evaluation of the fidelity of experimental results of Mininet-ns3-WiFi. We further present a reliable and low cost method that gives an experimenter an indicator about the fidelity and trustworthiness of the results

Link capacity estimation in wireless software defined networks

SDN is a new approach to manage networks with a centralised, global view and control of the network, and a more fine grained and flexible approach to routing and forwarding of data packets. This has shown to achieve significantly increased network efficiency in a range of wired networks. SDN also has a great potential for wireless networks. One of the unique challenges of applying the SDN approach to wireless networks, in contrast to wired networks, is the dynamic nature of wireless links and the uncertainty about their capacity. In order to be able to do optimal routing and traffic engineering with SDN in a wireless network, it is critical to know the capacity of the available wireless links. This paper presents a link capacity estimation mechanism that can be implemented on any OpenFlow SDN controller. For this, we adapted the well-known technique of packet pair/train probing, and developed a method that allows the correction of estimation errors induced by cross traffic. We have implemented a prototype for the Ryu SDN controller, and our emulation-based experimental results show a promising accuracy of our proposed approach

Securing ARP in software defined networks

The mapping of Layer 3 (IP) to Layer 2 (MAC) addresses is a key service in IP networks, and is achieved via the ARP protocol in IPv4, and the NDP protocol in IPv6. Due to their stateless nature and lack of authentication, both ARP and NDP are vulnerable to spoofing attacks, which can enable Denial of Service (DoS) or man-in-the-middle (MITM) attacks. In this paper, we discuss the problem of ARP spoofing in the context of Software Defined Networks (SDNs), and present a new mitigation approach which leverages the centralised network control of SDN