Justin P. Rohrer

Naval Postgraduate School | NPS · Department of Computer Science

The topological structure of the Internet – the interconnection of routers and autonomous systems (ASes) – is large and complex. Frequently it is necessary to evaluate network protocols and applications on " Internet-like " graphs in order understand their security, resilience, and performance properties. A fundamental obstacle to emulation and sim...

Path Diversification is a new mechanism that can be used to select multiple paths between a given ingress and egress node pair using a quantified diversity measure to achieve maximum flow reliability. The path diversification mechanism is targeted at the end-to-end layer, but can be applied at any level for which a path discovery service is availab...

We present an architecture for combining two established network paradigms, IP and Disruption-Tolerant Networking (DTN), into a unified packet gateway design that leverages the advantages of both. Vehicular networking (VNET) scenarios often involve brittle links between communicating nodes due to their mobility. DTN solutions, by using a dynamic ho...

Discovering router-level IPv6 topologies is important to un-derstanding IPv6 growth, structure, and evolution and relation to IPv4. This work presents a fingerprint-based IPv6 alias resolution technique that induces fragmented responses from IPv6 router interfaces. We lever-age the way in which IPv6 implements fragmentation to provide reliable infe...

Highly-dynamic wireless environments present unique challenges to end-to-end communication networks, caused by the time-varying connectivity of high-velocity nodes combined with the unreliability of the wireless communication channel. Such conditions are found in a variety of networks, including those used for tactical communications and aeronautic...

We describe a new system for distributed tracing at the IP level of the routes that packets take through the IPv4 internet. Our Zeph algorithm coordinates route tracing efforts across agents at multiple vantage points, assigning to each agent a number of /24 destination prefixes in proportion to its probing budget and chosen according to a reinforc...

Existing methods for active topology discovery within the IPv6 Internet largely mirror those of IPv4. In light of the large and sparsely populated address space, in conjunction with aggressive ICMPv6 rate limiting by routers, this work develops a different approach to Internet-wide IPv6 topology mapping. We adopt randomized probing techniques in or...

We present the Epidemic routing protocol implementation in ns-3. It is a full-featured DTN protocol in that it supports the message abstraction and store-and-haul behavior. We compare the performance of our Epidemic routing ns-3 implementation with the existing implementation of Epidemic in the ONE simulator, and discuss the differences.

Existing methods for active topology discovery within the IPv6 Internet largely mirror those of IPv4. In light of the large and sparsely populated address space, in conjunction with aggressive ICMPv6 rate limiting by routers, this work develops a different approach to Internet-wide IPv6 topology mapping. We adopt randomized probing techniques in or...

A number of geolocation-based Delay Tolerant Networking (DTN) routing protocols have been shown to perform well in selected simulation and mobility scenarios. However, the suitability of these mechanisms for vehicular networks utilizing widely-available inexpensive Global Positioning System (GPS) hardware has not been evaluated. We propose a novel...

The first book to focus on the communications and networking aspects of UAVs, this unique resource provides the fundamental knowledge needed to pursue research in the field. The team of authors covers the foundational concepts of the topic, as well as offering a detailed insight into the state of the art in UAVs and UAV networks, discussing the reg...

The class of flooding-based DTN routing protocols that leverage (transitive) encounter probabilities have been shown to perform well in selected simulations and scenarios, however they are especially sensitive to heterogeneous mobility models in which some nodes' mobility pattern is on a significantly different timescale than others. In particular,...

The IPv6 Internet is an important component of the Internet's continued growth and evolution. By several metrics, IPv6 has grown exponentially and now carries nontrivial amounts of production traffic. Less well-understood, however, is IPv6's topology and the way in which providers are using their IPv6 address allocations. Rather than relying on pas...

To support emerging application classes and network use paradigms for Future Internet resilience, we are designing a new transport protocol: ResTP. ResTP overcomes the limitations of TCP and UDP that evolved in the context of the fixed, wired, connected, relatively reliable, and low-to-moderate delay Internet. ResTP is developed to efficiently carr...

Network researchers and operators often turn to emulation and simulation for testing and experimentation. Obtaining topologies that reflect the graph characteristics of the Internet, while of small enough order to emulate or simulate on commodity hardware, however, is a difficult undertaking.In this work, we reexamine a previous study devoted to ge...

In this paper, we present the SmartNet architecture, an open and extensible software framework for experimenting with and deploying application-transparent network adaptation solutions. The framework fashions a plugin-based system architecture where each plugin implements a small set of application or transport protocol specific network adaptation...

In this paper we analyze several Crowd-Sourced Serious Games (CSSGs), a new genre focused on advancing widely respected causes such as social equality and science. We observe that the general effectiveness of these games has remained largely unknown. Existing performance analyses have been limited to documenting experiences with individual systems....

The Great Plains Environment for Network Innovation (GpENI) is an international programmable network testbed centered initially in the Midwest US with the goal to provide programmability across the entire protocol stack. In this paper, we present the overall GpENI framework and our implementation experience for the programmable routing environment...

The aeronautical ANTP protocol suite consisting of AeroTP, AeroRP, and AeroNP has been designed to cope with the challenges in highly-dynamic airborne networks. Via simulations, these protocols have shown significant improvement compared with other traditional protocols. In this paper, we present a prototype implementation of ANTP protocol suite us...

For many years the research community has attempted to model the Internet in order to better understand its behaviour and improve its performance. Since much of the structural complexity of the Internet is due to its multilevel operation, the Internet’s multilevel nature is an important and non-trivial feature that researchers must consider when de...

The domain-specific ANTP protocol suite consisting of AeroTP, AeroRP, and AeroNP has been developed to cope with the challenges in highly-dynamic airborne telemetry networks. These protocols have been designed and modelled through simulation methodology. In this paper, we present an implementation of the AeroRP and AeroNP components in Python. Init...

Telemetry networks often operate in challenged wireless environments, resulting in periods of disconnection. Our delay tolerant networking (DTN) gateway dynamically detects disruptions in connectivity and buffers telemetry data until connectivity is reestablished. When the connection is resumed, all buffered data is transmitted automatically in ord...

Transport protocols in highly-dynamic airborne networks call for adaptive error-control mechanisms to provide efficient error detection and recovery. Due to the highly dynamic nature of these networks and short contact durations between the nodes, the AeroTP protocol uses an adaptive multi-mode mechanism to provide a varying degree of reliable serv...

Due to the challenging network conditions posed by a highly-dynamic airborne telemetry environment, it is essential for the transport protocol to provide automated mechanisms that dynamically adapt to changing end-to-end performance on any path. The AeroTP multi-mode transport protocol provides service tailored to the requirements of the telemetry...

Understanding and modelling the Internet has been a major research challenge in part due to the complexity of the interaction among its protocols and in part due to multilevel, multidomain topological structure. It is therefore crucial to properly analyse each structural level of the Internet to gain a better understanding, as well as to improve it...

End-to-end communication in highly-dynamic airborne networks is challenging due to the presence of highly mobile nodes and the inherent nature of wireless communication channels. Domain-specific protocols are required that can address these challenges and enable reliable transmission of data in this environment. We develop the ANTP (airborne networ...

Communication networks are constructed as a multilevel stack of infrastructure, protocols, and mechanisms: links and nodes, topology, routing paths, interconnected realms (ASs), end-to-end transport, and application interaction. The resilience of each one of these levels provides a foundation for the next level to achieve an overall goal of a resil...

As the Internet becomes increasingly impor-tant to all aspects of society, the consequences of dis-ruption become increasingly severe. Thus it is critical to increase the resilience and survivability of future net-works. We define resilience as the ability of the network to provide desired service even when challenged by at-tacks, large-scale disas...

The universal reliance on and hence the need for resilience in network communications has been well established. Current transport protocols are designed to provide fixed mechanisms for error remediation (if any), using techniques such as ARQ, and offer little or no adaptability to underlying network conditions, or to different sets of application...

Emerging airborne networks require domainspecific routing protocols to cope with the challenges faced by the highly-dynamic aeronautical environment. We present an ns-3 based performance comparison of the AeroRP protocol with conventional MANET routing protocols. To simulate a highly-dynamic airborne network, accurate mobility models are needed for...

Due to the highly-dynamic nature of airborne telemetry networks, we have developed the ANTP pro-tocol suite consisting of AeroTP, AeroRP, and AeroNP. Having verified these protocols through simulation and analysis, the next step towards deployment of the ANTP suite is developing a cross-platform imple-mentation of the protocols. Towards this end we...

Due to the challenging network conditions posed by a highly-dynamic airborne telemetry environment, it is essential for the transport protocol to provide automated mechanisms that dynamically adapt to changing end-to-end performance on any path. The AeroTP multi-mode transport protocol provides service tailored to the requirements of the telemetry...

Millimeter-wave mesh networks have the potential to provide cost-effective high-bandwidth solutions to many current bandwidth-constrained networks including cellular backhaul. However, the availability of such networks is severely limited due to their susceptibility to weather, such as precipitation and humidity. In this paper, we present a rigorou...

Routing protocols are a critical aspect to performance in mobile wireless networks. The development of new protocols requires testing against well-known protocols in various sim-ulation environments. In this paper we present an overview of several well-known MANET routing protocols and the implementation details of the DSDV routing protocol in the...

As the Internet becomes increasingly important to all aspects of society, the consequences of disruption become increasingly severe. Thus it is critical to increase the resilience and survivability of the future network. We define resilience as the ability of the network to provide desired service even when challenged by attacks, large-scale disast...

GpENI is evolving to provide a promising environment in which to do experimental research in the resilience and survivability of future networks, by allowing programmable control over topology and mechanism, while providing the scale and global reach needed to conduct network experiments far beyond the capabilities of a conventional testbed. Addres...

In this paper we extend our path diversity metric to create a composite compensated total graph diversity metric that is representative of a particular topology's survivability with respect to distributed simultaneous link and node failures. We tune the accuracy of this metric using 17 topologies, including 3 real fiber maps, 10 inferred logical ma...

Airborne telemetry networks are an example of a wireless network domain with much higher mobility than either the Internet or MANET protocols were designed to cope with. The very high speeds and distances covered, combined with limited radio transmission power contribute to making fully-connected operation impossible in this environment. We present...

As society increasingly depends on networks for all aspects of its functioning, the consequences of its disruption become increasingly severe, as does its attractiveness to crackers and terrorists who wish to disrupt society. It is therefore essential to understand and evaluate the resilience of current networks, and to evaluate alternatives for fu...

The Internet has become essential to all aspects of modern life, and thus the consequences of network disruption have become increasingly severe. It is widely recognised that the Internet is not sufficiently resilient, survivable, and dependable, and that significant research, development, and engineering is necessary to improve the situation. This...

Due to the mission-critical nature of command-and-control traffic in the telemetry environment, it is imperative that reliable transfer be supported. The AeroTP disruption-tolerant transport protocol is intended for this environment. The mechanism for reliable transfer is ARQ with end-to- end acknowledgments. This has significant performance limita...

We present Path Diversification, a new mechanism that can be used to select multiple paths between a given ingress and egress node pair using a quantified diversity measure to achieve maximum flow reliability. The path diversification mechanism is targeted at the end-to-end layer, but can be applied at any level for which a path discovery service i...

As society's dependence on network technology increases, the need for resilience and survivability in these services becomes increasingly apparent. Since the user experience is ultimately determined by the dependability of the end-to-end service, we address this issue at the transport layer. In this paper we introduce a resilient multipath selectio...

With growing demand for high-speed access to mobile handheld devices, there is a significant cost benefit in deploying fixed wireless-mesh networks for backhaul access. However, enabling reliable broadband access over high-frequency radios (such as millimeter-wave networks) posses a fundamental challenge due to weather disruptions in general and ra...

The airborne telemetry environment presents unique challenges to end-to-end communications due to the highly dynamic topology and time-varying connectivity of high-velocity wireless nodes. The AeroTP transport protocol uses multiple reliability modes to trade off end-to-end reliability and efficiency as appropriate for different categories of telem...

Highly dynamic mobile wireless networks present unique challenges to end-to-end communication, particularly caused by the time varying connectivity of high-velocity nodes combined with the unreliability of the wireless communication channel. Addressing these challenges requires the design of new protocols and mechanisms specific to this environment...

Problems with traditional TCP

Networks of airborne nodes provide unique challenges to end-to-end communication, in particular due to the highly dynamic topology and time-varying connectivity of high velocity nodes, and unreliability of the wireless communication channel. This paper explores the issues and presents a design for a domainspecific transport protocol targeted to mul...

This paper presents the Bioinformatics Computational Journal (BCJ), a framework for conducting and managing computational experiments in bioinformatics and computational biology. These experiments often involve series of computations, data searches, filters, and annotations which can benefit from a structured environment. Systems to manage computat...

The promises of next-generation Internet architectures are many and varied. Key among these are increased flexibility and diversity. What this translates into is increased variety not only in protocols and technology, but in the performance characteristics and services provided by these composite or heterogeneous networks. This is certainly true of...