Abstract: Software Defined Networking (SDN) is driving transformations in Research and Education (R&E) networks, enabling innovations in network research, enhancing network performance, and providing security through a policy-driven network management framework. The Holland Computing Center (HCC) at the University of Nebraska-Lincoln (UNL) supports scientists studying large datasets, and has identified a need for flexibility in network management and security, particularly with respect to identifying data flows. This problem is addressed through the deployment of a production SDN with a focus on integrating network resource management for large-scale GridFTP data transfers. We propose SNAG (SDN-managed Network Architecture for GridFTP transfers), an architecture that enables the SDN-based network management of GridFTP file transfers for large-scale science datasets. We also show how SNAG can efficiently and securely identify science dataset transfers from projects such as Compact Muon Solenoid (CMS) and Laser Interferometer Gravitational-Wave Observatory (LIGO). We focus on exposing an Application Program Interface (API) between the trusted GridFTP process and the network layer allowing the network to track flows via application metadata.
Abstract— Security forms an important part of wireless network communication systems. A wide variety of attacks can be performed on IEEE 802.11 MAC thereby compromising the security of the system and also leading to degradation of the system performance. The security attacks can be classified into different categories based on criteria/nature of the attack, domain or attack techniques used. In this work we study the performance of IEEE 802.11 MAC with CSMA/CA systems under various jamming attacks. The study will comprise of simulation of jamming attacks and its effect on various system parameters like throughput, latency, offered load, etc.
Abstract—4th generation networks postulate high speed ubiquitous coverage for all types of mobility which in turn demands seamless handover of connectivity from one network to another. This has necessitated a detailed performance study of handover among homogeneous and heterogeneous networks. This document summarizes our analysis of various types of handoffs among wireless networks. A detailed study of two poplar wireless access networks namely, WiMax(802.16) and WLAN(802.11) has been performed and the handover mechanisms among them have been studied. To this end, we have analyzed performance of two types of handoffs – horizontal handoff between two homogeneous networks (WLAN-WLAN or WiMax-WiMax) and vertical handoff between two heterogeneous networks (WLAN-WiMax). In order to study the performance of vertical handoff, IEEE 802.21 Media Independent Handover has been employed. Metrics like Average handoff distances for varying power threshold in layer 2 and 3 and packet drop rate for varying speed have been studied and conclusions have been drawn for different scenarios.
Keywords: IEEE802.11e, IEEE802.16, IEEE802.21 Media Independent Handover,Intersystem Handover.
Abstract—Security forms an important part of wireless network communication system. A variety of attacks can be performed on 802.11 MAC thereby compromising the security of the system and also leading to degradation of the system performance. The security attacks can be classified into different categories based on criteria nature of the attack, domain or attack techniques used. In this work we study the performance of IEEE 802.11 MAC with CSMA/CA systems under various jamming attacks. The study will comprise of simulation of jamming attacks and its effect on various system parameters like throughput, latency, offered load, etc.
Keywords—802.11 DCF, 802.11 EDCA, Jamming attacks.
Abstract: The use of Internet protocol suite of TCP/UDP in environments characterized by high delay and high link error rates result in significant degradation of the Protocol performance. The DTN bundle protocol can be used in such scenarios. Performance evaluation of delay-tolerant network bundle protocol in a live network is difficult due to the absence of networks characterized by extreme environs. Control on specific performance metrics like link delay, bandwidth, connectivity, traffic flow and queue sizes are thus rendered impossible without the incorporation of a control system either in software implementation or network hardware. The control over specific environments in real- world deployments and the analysis of the protocol deployment in the above provides an understanding into the performance of the bundling protocol in harsh networking environments. This paper presents the analysis and evaluation of performance of a delay-tolerant network in a virtual test platform setup.
Keywords: Internet, delays, transport protocols, Internet protocol, TCP/UDP, delay-tolerant network bundling protocol, scalable virtual network.
Abstract—The evolutions in space technologies are facilitating the realization of scientific deep space missions. Unpredictable link reliability, network connectivity, large round trip times (RTT) and wide variations in transmission latencies are characteristics of such networks. This could pose significant problems for deep space missions. Also the present day Internet protocols are ill suited for the purpose of deep space missions as performance deteriorates quickly under the above above-mentioned conditions. The work undertaken ndertaken presents a delay-tolerant network (DTN) communication system architectural design, design and modeling of DTN Bundle Protocol and Characterization, Analysis and Performance evaluation of such networks.
Abstract—Network Simulation is a predominant way of evaluating network performance of new routing algorithms and protocols. Discrete event simulation systems provide environments suitable for performance analysis. Dedicated simulation systems/small scale deployments of Delay-Tolerant Networks(DTN) are currently in use to explore the behavior and performance of Delay-Tolerant Networking Protocols and Architectures. The available simulation systems provide for varying system configurations at different levels of the protocol stack with the requirement for certain duplication/modification of the specified applications and protocols within the simulation environment. Also the simulation system depends on a flexible model of the developed system than the system itself. A real-world deployment discussed in  accommodates a link emulation system to provide a controlled environment for testing and analysis of Delay-Tolerant Networks. The development of a controlled test environment for deployment of a Delay-Tolerant Networking system requires significant infrastructure with complexities involving scalability and mobility. In this paper we present a scalable virtual networking test platform for deployment of delay-tolerant networks.