Master of Science

Named data networking (NDN) is a content-centric future Internet architecture that uses routable content names instead of IP addresses to achieve location-independent forwarding. Nevertheless, NDN's design is limited to offering hosted applications a simple content pull mechanism. As a result, increased complexity is needed in developing applications that require more sophisticated content delivery functionalities (e.g., push, publish/subscribe, streaming, generalized forwarding, and dynamic content naming). This thesis introduces a novel Enhanced NDN (ENDN) architecture that offers an extensible catalog of content delivery services (e.g., adaptive forwarding, customized monitoring, and in-network caching control). More precisely, the proposed architecture allows hosted applications to associate their content namespaces with a set of services offered by ENDN. The design of ENDN starts from the current NDN architecture that is gradually modified to meet the evolving needs of novel applications. NDN switches use several forwarding tables in the packet processing pipeline, the most important one being the Forwarding Information Base (FIB). The NDN FIBs face stringent performance requirements, especially in Internet-scale deployments. Hence, to increase the NDN data plane scalability and flexibility, we first propose FCTree, a novel FIB data structure. FCTree is a compressed FIB data structure that significantly reduces the required storage space within the NDN routers while providing fast lookup and modification operations. FCTree also offers additional lookup types that can be used as building blocks to novel network services (e.g., in-network search engine). Second, we design a novel programmable data plane for ENDN using P4, a prominent data plane programming language. Our proposed data plane allows content namespaces to be processed by P4 functions implementing complex stateful forwarding behaviors. We thus extend existing P4 models to overcome their limitations with respect to processing string-based content names. Our proposed data plane also allows running independent P4 functions in isolation, thus enabling P4 code run-time pluggability. We further enhance our proposed data plane by making it protocol-independent using programmable parsers to allow interfacing with IP networks. Finally, we introduce a new control plane architecture that allows the applications to express their network requirements using intents. We employ Event-B machine (EBM) language modeling and tools to represent these intents and their semantics on an abstract model of the network. The resulting EBMs are then gradually refined to represent configurations at the programmable data plane. The Event-B method formally ensures the consistency of the different application requirements using proof obligations and verifies that the requirements of different intents do not contradict each other. Thus, the desired properties of the network or its services, as defined by the intent, are guaranteed to be satisfied by the refined EBM representing the final data-plane configurations. Experimental evaluation results demonstrate the feasibility and efficiency of our proposed architecture.

<p> Connectionist models of language acquisition typically have difficulty with systematicity, or the ability for the network to generalize its limited experience with language to novel utterances. In this way, connectionist systems learning grammar from a set of example sentences tend to store a set of specific instances, rather than a generalized abstract knowledge of the process of grammatical combination. Further, recent models that do show limited systematicity do so at the expense of simultaneously storing explicit lexical knowledge, and also make use of both developmentally-implausible training data and biologically-implausible learning rules. Consequently, this research program develops a novel unsupervised neural network architecture, and applies this architecture to the problem of systematicity in language models.</p> <p> In the first of several studies, a connectionist architecture capable of simultaneously storing explicit and separate representations of both conceptual and grammatical information is developed, where this architecture is a hybrid of both a self-organizing map and an intra-layer Hebbian associative network. Over the course of several studies, this architecture's capacity to acquire linguistic grammar is evaluated, where the architecture is progressively refined until it is capable of acquiring a benchmark grammar consisting of several difficult clausal sentence structures - though it must acquire this grammar at the level of grammatical category, rather than the lexical level.</p> <p> The final study bridges the gap between the lexical and grammatical category levels, and develops an activation function based on a semantic feature co-occurrence metric. In concert with developmentally-plausible sensorimotor grounded conceptual representations, it is shown that a network using this metric is able to undertake a process of semantic bootstrapping, and successfully acquire separate explicit representations at the level of the concept, part-of-speech category, and grammatical sequence. This network demonstrates broadly systematic behaviour on a difficult test of systematicity, and extends its knowledge of grammar to novel sensorimotor-grounded words.</p> / Thesis / Doctor of Philosophy (PhD)

There is an ongoing evolution of technology towards network convergence and ubiquitous information society in which users have broadband access to information resources and services anywhere, anytime. To realize this vision, a communication infrastructure has to be able to support a core backbone network delivering ultra-high capacity data services, a ubiquitous broadband wireless for last-mile access, and a control/management plane providing intelligent control to the infrastructure. Desirable characteristics of the infrastructure include insertion of future technology, intelligent spectrum management, cost-efficient upgradeability, flexible scalability, and cognitive networking capabilities. Unfortunately, present electronic technology alone is incapable of meeting these requirements.This dissertation describes the initial research into the realization of such an architecture that comprises of three crucial frameworks: 1) photonic-based; 2) dynamic chain processing; 3) and physical layer awareness. Due to the superior signal transport properties of optics, an underlying photonic data layer is able to provide the architecture with much wider bandwidth, greater RF-frequency-scalability, and higher operating RF-frequency. Photonics also enables diverse technologies to be integrated into a seamless communications platform. Dynamic processing chain framework provides the flexibility and future-proof capability via reconfigurability and componentization. Physical-layer-awareness offers support for automated adaptation and intelligent configuration of the data plane in response to the dynamic conditions of the physical layer. Crucial functional blocks in this awareness are: efficient estimation of physical impairments of the components and links; an effective dynamic impairment monitoring mechanism; and proficient adaptation to either maximize or optimize performance.Though the architecture encompasses both optical transport network (OTN) and photonic radio, this dissertation focuses more on the OTN. Central themes of OTN in this dissertation include relating Q-factor with various optical impairments from the perspective of an end-to-end optical path, and extending physical layer awareness with impairment routing. One of the key findings advocates that filtering is a serious limitation to bit-rate independence, protocol independence and network scalability promised by transparent network.

The use of permutations in data compression is an aspect that is worthy of further exploration. The work that has been done in video compression based on permutations was primarily oriented towards lossless algorithms. The study of previous algorithms has led to a new algorithm that could be either lossless or lossy, for which the amount of compression and the quality of the output can be controlled. The lossless version of our algorithm performs close to lossy versions of H.264 and it improves on them for the majority of the videos that we analyzed. Our algorithm could be used in situations where there is a need for lossless compression and the video sequences are part of a single scene, e.g., medical videos, where loss of information could be risky or expensive. Some results on permutations, which may be of independent interest, arose in developing this algorithm. We report on these as well. / by Amalya Mihnea. / Thesis (Ph.D.)--Florida Atlantic University, 2011. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2011. Mode of access: World Wide Web.

While international academic and research collaborations are of great importance at this time, it is not easy to find researchers in the engineering field that publish in languages other than English. Because of this disconnect, there exists a need for a portal to find Who’s Who in Engineering Education in the Americas. The objective of this thesis is to built an object-oriented architecture for this proposed portal. The Unified Modeling Language (UML) model developed in this thesis incorporates the basic structure of a social network for academic purposes. Reverse engineering of three social networks portals yielded important aspects of their structures that have been incorporated in the proposed UML model. Furthermore, the present work includes a pattern for academic social networks. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection

With the growing number of clean-slate redesigns of the Internet, the need for a medium that enables all stakeholders to participate in the realization, evaluation, and selection of these designs is increasing. We believe that the missing catalyst is a meta network architecture that welcomes most, if not all, clean-state designs on a level playing field, lowers deployment barriers, and leaves the final evaluation to the broader community. This thesis presents the eXpressive Internet (Meta) Architecture (XIA), itself a clean-slate design, as well as Linux XIA, a native implementation of XIA in the Linux kernel, as a candidate. As a meta network architecture, XIA is highly flexible, leaving stakeholders to choose an expressive set of network principals to instantiate a given network architecture within the XIA framework. Central to XIA is its novel, non-linear network addressing format, from which derive key architectural features such as evolvability, intrinsically secure identifiers, and a low degree of principal isolation. XIP, the network layer protocol of XIA, forwards packets by navigating these structured addresses and delegating the decision-making and packet processing to appropriate principals, accordingly. Taken together, these mechanisms work in tandem to support a broad spectrum of interoperable principals. We demonstrate how to port four distinct and unrelated network architectures onto Linux XIA, none of which were designed for interoperability with this platform. We then show that, notwithstanding this flexibility, Linux XIA's forwarding performance remains comparable to that of the more mature legacy TCP/IP stack implementation. Moreover, the ported architectures, namely IP, Serval, NDN, and ANTS, empower us to present a deployment plan for XIA, to explore design variations of the ported architectures that were impossible in their original form due to the requirement of self-sufficiency that a standalone network architecture bears, and to substantiate the claim that XIA readily supports and enables network evolution. Our work highlights the benefits of specializing network designs that XIA affords, and comprises instructive examples for the network researcher interested in design and implementation for future interoperability.

Nowadays there is an increasing need for a general paradigm that can simplify network management and further enable network innovations. Software Defined Networking (SDN) is an efficient way to make the network programmable and reduce management complexity, however it is plagued with limitations inherited from the legacy Internet (TCP/IP) architecture. On the other hand, service overlay networks and virtual networks are widely used to overcome deficiencies of the Internet. However, most overlay/virtual networks are single-layered and lack dynamic scope management. Furthermore, how to solve the joint problem of designing and mapping the overlay/virtual network requests for better application and network performance remains an understudied area. In this thesis, in response to limitations of current SDN management solutions and of the traditional single-layer overlay/virtual network design, we propose a recursive approach to enterprise network management, where network management is done through managing various Virtual Transport Networks (VTNs) over different scopes (i.e., regions of operation). Different from the traditional overlay/virtual network model which mainly focuses on routing/tunneling, our VTN approach provides communication service with explicit Quality-of-Service (QoS) support for applications via transport flows, i.e., it involves all mechanisms (e.g., addressing, routing, error and flow control, resource allocation) needed to meet application requirements. Our approach inherently provides a multi-layer solution for overlay/virtual network design. The contributions of this thesis are threefold: (1) we propose a novel VTN-based management approach to enterprise network management; (2) we develop a framework for multi-layer VTN design and instantiate it to meet specific application and network goals; and (3) we design and prototype a VTN-based management architecture. Our simulation and experimental results demonstrate the flexibility of our VTN-based management approach and its performance advantages.

Despite the huge success and adoption of computer networks in the recent decades, traditional network architecture falls short of some requirements by many applications. One particular shortcoming is the lack of convenient methods for providing quality of service (QoS) guarantee to various network applications. In this dissertation, we explore new Software-Defined Networking (SDN) mechanisms to provision QoS to targeted network flows. Our study contributes to providing QoS support to applications in three aspects. First, we explore using alternative routing paths for selected flows that have QoS requirements. Instead of using the default shortest path used by the current network routing protocols, we investigate using the SDN controller to install forwarding rules in switches that can achieve higher bandwidth. Second, we develop new mechanisms for guaranteeing the latency requirement by those applications depending on timely delivery of sensor data and control signals. The new mechanism pre-allocates higher priority queues in routers/switches and reserves these queues for control/sensor traffic. Third, we explore how to make the applications take advantage of the opportunity provided by SDN. In particular, we study new transmission mechanisms for big data transfer in the cloud computing environment. Instead of using a single TCP path to transfer data, we investigate how to let the application set up multiple TCP paths for the same application to achieve higher throughput. We evaluate these new mechanisms with experiments and compare them with existing approaches.

Self-organizing overlay networks have emerged as a powerful paradigm for providing network services. While most approaches assume that overlay networks are built over a single substrate network, generally, the Internet, this thesis addresses the construction of overlay networks over multiple substrate networks. We present the design, implementation and evaluation of Cross-Substrate Advertisement (CSA) mechanisms for overlay networks over multiple heterogeneous substrate networks. A key difficulty arises from the more complex address bindings, since a single logical identifier is bound to multiple substrate addresses. We present mechanisms for exchanging information on address bindings and evaluate their effectiveness. The CSA mechanisms have been implemented in the HyperCast overlay protocol architecture, and have been evaluated in measurement experiments on an Emulab testbed. The experiments show that our CSA methods are effective in disseminating address information in large networks and are robust in the presence of network disruptions.