Chemical Reaction Optimization for population transition in peer-to-peer live streaming

Peer-to-peer (P2P) live streaming applications are very popular in recent years and a Markov open queueing network model was developed to study the population dynamics in P2P live streaming. Based on the model, we deduce an optimization problem, called population transition problem, with the objective of maximizing the probability of universal streaming by manipulating population transition probability matrix. We employ a chemical reaction-inspired metaheuristic, Chemical Reaction Optimization (CRO), to solve the problem. Simulation results show that CRO outperforms many commonly used strategies for controlling population transition in many practical P2P live streaming systems. This work also shows that CRO also demonstrates the usability of CRO to solve optimization problems. © 2010 IEEE.published_or_final_versionThe IEEE Congress on Evolutionary Computation (CEC), Barcelona, Spain, 18-23 July 2010. In Proceedings of the IEEE CEC, 2010, p. 1-

Scalable playback rate control in P2P live streaming systems

Current commercial live video streaming systems are based either on a typical client–server (cloud) or on a peer-to-peer (P2P) architecture. The former architecture is preferred for stability and QoS, provided that the system is not stretched beyond its bandwidth capacity, while the latter is scalable with small bandwidth and management cost. In this paper, we propose a P2P live streaming architecture in which by adapting dynamically the playback rate we guarantee that peers receive the stream even in cases where the total upload bandwidth changes very abruptly. In order to achieve this we develop a scalable mechanism that by probing only a small subset of peers monitors dynamically the total available bandwidth resources and a playback rate control mechanism that dynamically adapts playback rate to the aforementioned resources. We model analytically the relationship between the playback rate and the available bandwidth resources by using difference equations and in this way we are able to apply a control theoretical approach. We also quantify monitoring inaccuracies and dynamic bandwidth changes and we calculate dynamically, as a function of these, the maximum playback rate for which the proposed system able to guarantee the uninterrupted and complete distribution of the stream. Finally, we evaluate the control strategy and the theoretical model in a packet level simulator of a complete P2P live streaming system that we designed in OPNET Modeler. Our evaluation results show the uninterrupted and complete stream delivery (every peer receives more than 99 % of video blocks in every scenario) even in very adverse bandwidth changes

Use of locator/identifier separation to improve the future internet routing system

The Internet evolved from its early days of being a small research network to become a critical infrastructure many organizations and individuals rely on. One dimension of this evolution is the continuous growth of the number of participants in the network, far beyond what the initial designers had in mind. While it does work today, it is widely believed that the current design of the global routing system cannot scale to accommodate future challenges. In 2006 an Internet Architecture Board (IAB) workshop was held to develop a shared understanding of the Internet routing system scalability issues faced by the large backbone operators. The participants documented in RFC 4984 their belief that "routing scalability is the most important problem facing the Internet today and must be solved." A potential solution to the routing scalability problem is ending the semantic overloading of Internet addresses, by separating node location from identity. Several proposals exist to apply this idea to current Internet addressing, among which the Locator/Identifier Separation Protocol (LISP) is the only one already being shipped in production routers. Separating locators from identifiers results in another level of indirection, and introduces a new problem: how to determine location, when the identity is known. The first part of our work analyzes existing proposals for systems that map identifiers to locators and proposes an alternative system, within the LISP ecosystem. We created a large-scale Internet topology simulator and used it to compare the performance of three mapping systems: LISP-DHT, LISP+ALT and the proposed LISP-TREE. We analyzed and contrasted their architectural properties as well. The monitoring projects that supplied Internet routing table growth data over a large timespan inspired us to create LISPmon, a monitoring platform aimed at collecting, storing and presenting data gathered from the LISP pilot network, early in the deployment of the LISP protocol. The project web site and collected data is publicly available and will assist researchers in studying the evolution of the LISP mapping system. We also document how the newly introduced LISP network elements fit into the current Internet, advantages and disadvantages of different deployment options, and how the proposed transition mechanism scenarios could affect the evolution of the global routing system. This work is currently available as an active Internet Engineering Task Force (IETF) Internet Draft. The second part looks at the problem of efficient one-to-many communications, assuming a routing system that implements the above mentioned locator/identifier split paradigm. We propose a network layer protocol for efficient live streaming. It is incrementally deployable, with changes required only in the same border routers that should be upgraded to support locator/identifier separation. Our proof-of-concept Linux kernel implementation shows the feasibility of the protocol, and our comparison to popular peer-to-peer live streaming systems indicates important savings in inter-domain traffic. We believe LISP has considerable potential of getting adopted, and an important aspect of this work is how it might contribute towards a better mapping system design, by showing the weaknesses of current favorites and proposing alternatives. The presented results are an important step forward in addressing the routing scalability problem described in RFC 4984, and improving the delivery of live streaming video over the Internet

Across-Peer Rate Allocation Algorithm in Peer-to-peer Networks

We introduce a new across-peer rate allocation algorithm with successive refinement to improve the video transmission performance in P2P networks, based on the combination of multiple description coding and network coding. Successive refinement is implemented through layered multiple description codes. The algorithm is developed to maximize the expected video quality at the receivers by partitioning video bitstream into different descriptions depending on different bandwidth conditions of each peer. Adaptive rate partition adjustment is applied to ensure the real reflection of the packet drop rate in the network. Also the granularity is changed to the scale of atomic blocks instead of stream rates in prior works. Through simulation results we show that the algorithm outperforms prior algorithms in terms of video playback quality at the peer ends, and helps the system adjust better to the peer dynamics

Reliable Client Accounting for Hybrid Content-Distribution Networks

Content distribution networks (CDNs) have started to adopt hybrid designs, which employ both dedicated edge servers and resources contributed by clients. Hybrid designs combine many of the advantages of infrastructurebased and peer-to-peer systems, but they also present new challenges. This paper identifies reliable client accounting as one such challenge. Operators of hybrid CDNs are accountable to their customers (i.e., content providers) for the CDN’s performance. Therefore, they need to offer reliable quality of service and a detailed account of content served. Service quality and accurate accounting, however, depend in part on interactions among untrusted clients. Using the Akamai NetSession client network in a case study, we demonstrate that a small number of malicious clients used in a clever attack could cause significant accounting inaccuracies. We present a method for providing reliable accounting of client interactions in hybrid CDNs. The proposed method leverages the unique characteristics of hybrid systems to limit the loss of accounting accuracy and service quality caused by faulty or compromised clients. We also describe RCA, a system that applies this method to a commercial hybrid content-distribution network. Using trace-driven simulations, we show that RCA can detect and mitigate a variety of attacks, at the expense of a moderate increase in logging overhead

Large-scale sensor-rich video management and delivery

Ph.DDOCTOR OF PHILOSOPH

On the scalability of LISP and advanced overlaid services

In just four decades the Internet has gone from a lab experiment to a worldwide, business critical infrastructure that caters to the communication needs of almost a half of the Earth's population. With these figures on its side, arguing against the Internet's scalability would seem rather unwise. However, the Internet's organic growth is far from finished and, as billions of new devices are expected to be joined in the not so distant future, scalability, or lack thereof, is commonly believed to be the Internet's biggest problem. While consensus on the exact form of the solution is yet to be found, the need for a semantic decoupling of a node's location and identity, often called a location/identity separation, is generally accepted as a promising way forward. Typically, this requires the introduction of new network elements that provide the binding of the two names-paces and caches that avoid hampering router packet forwarding speeds. But due to this increased complexity the solution's scalability is itself questioned. This dissertation evaluates the suitability of using the Locator/ID Separation Protocol (LISP), one of the most successful proposals to follow the location/identity separation guideline, as a solution to the Internet's scalability problem. However, because the deployment of any new architecture depends not only on solving the incumbent's technical problems but also on the added value that it brings, our approach follows two lines. In the first part of the thesis, we develop the analytical tools to evaluate LISP's control plane scalability while in the second we show that the required control/data plane separation provides important benefits that could drive LISP's adoption. As a first step to evaluating LISP's scalability, we propose a methodology for an analytical analysis of cache performance that relies on the working-set theory to estimate traffic locality of reference. One of our main contribution is that we identify the conditions network traffic must comply with for the theory to be applicable and then use the result to develop a model that predicts average cache miss rates. Furthermore, we study the model's suitability for long term cache provisioning and assess the cache's vulnerability in front of malicious users through an extension that accounts for cache polluting traffic. As a last step, we investigate the main sources of locality and their impact on the asymptotic scalability of the LISP cache. An important finding here is that destination popularity distribution can accurately describe cache performance, independent of the much harder to model short term correlations. Under a small set of assumptions, this result finally enables us to characterize asymptotic scalability with respect to the amount of prefixes (Internet growth) and users (growth of the LISP site). We validate the models and discuss the accuracy of our assumptions using several one-day-long packet traces collected at the egress points of a campus and an academic network. To show the added benefits that could drive LISP's adoption, in the second part of the thesis we investigate the possibilities of performing inter-domain multicast and improving intra-domain routing. Although the idea of using overlaid services to improve underlay performance is not new, this dissertation argues that LISP offers the right tools to reliably and easily implement such services due to its reliance on network instead of application layer support. In particular, we present and extensively evaluate Lcast, a network-layer single-source multicast framework designed to merge the robustness and efficiency of IP multicast with the configurability and low deployment cost of application-layer overlays. Additionally, we describe and evaluate LISP-MPS, an architecture capable of exploiting LISP to minimize intra-domain routing tables and ensure, among other, support for multi protocol switching and virtual networks.En menos de cuatro décadas Internet ha evolucionado desde un experimento de laboratorio hasta una infraestructura de alcance mundial, de importancia crítica para negocios y que atiende a las necesidades de casi un tercio de los habitantes del planeta. Con estos números, es difícil tratar de negar la necesidad de escalabilidad de Internet. Sin embargo, el crecimiento orgánico de Internet está aún lejos de finalizar ya que se espera que mil millones de dispositivos nuevos se conecten en el futuro cercano. Así pues, la falta de escalabilidad es el mayor problema al que se enfrenta Internet hoy en día. Aunque la solución definitiva al problema está aún por definir, la necesidad de desacoplar semánticamente la localización e identidad de un nodo, a menudo llamada locator/identifier separation, es generalmente aceptada como un camino prometedor a seguir. Sin embargo, esto requiere la introducción de nuevos dispositivos en la red que unan los dos espacios de nombres disjuntos resultantes y de cachés que almacenen los enlaces temporales entre ellos con el fin de aumentar la velocidad de transmisión de los enrutadores. A raíz de esta complejidad añadida, la escalabilidad de la solución en si misma es también cuestionada. Este trabajo evalúa la idoneidad de utilizar Locator/ID Separation Protocol (LISP), una de las propuestas más exitosas que siguen la pauta locator/identity separation, como una solución para la escalabilidad de la Internet. Con tal fin, desarrollamos las herramientas analíticas para evaluar la escalabilidad del plano de control de LISP pero también para mostrar que la separación de los planos de control y datos proporciona un importante valor añadido que podría impulsar la adopción de LISP. Como primer paso para evaluar la escalabilidad de LISP, proponemos una metodología para un estudio analítico del rendimiento de la caché que se basa en la teoría del working-set para estimar la localidad de referencias. Identificamos las condiciones que el tráfico de red debe cumplir para que la teoría sea aplicable y luego desarrollamos un modelo que predice las tasas medias de fallos de caché con respecto a parámetros de tráfico fácilmente medibles. Por otra parte, para demostrar su versatilidad y para evaluar la vulnerabilidad de la caché frente a usuarios malintencionados, extendemos el modelo para considerar el rendimiento frente a tráfico generado por usuarios maliciosos. Como último paso, investigamos como usar la popularidad de los destinos para estimar el rendimiento de la caché, independientemente de las correlaciones a corto plazo. Bajo un pequeño conjunto de hipótesis conseguimos caracterizar la escalabilidad con respecto a la cantidad de prefijos (el crecimiento de Internet) y los usuarios (crecimiento del sitio LISP). Validamos los modelos y discutimos la exactitud de nuestras suposiciones utilizando varias trazas de paquetes reales. Para mostrar los beneficios adicionales que podrían impulsar la adopción de LISP, también investigamos las posibilidades de realizar multidifusión inter-dominio y la mejora del enrutamiento dentro del dominio. Aunque la idea de utilizar servicios superpuestos para mejorar el rendimiento de la capa subyacente no es nueva, esta tesis sostiene que LISP ofrece las herramientas adecuadas para poner en práctica de forma fiable y fácilmente este tipo de servicios debido a que LISP actúa en la capa de red y no en la capa de aplicación. En particular, presentamos y evaluamos extensamente Lcast, un marco de multidifusión con una sola fuente diseñado para combinar la robustez y eficiencia de la multidifusión IP con la capacidad de configuración y bajo coste de implementación de una capa superpuesta a nivel de aplicación. Además, describimos y evaluamos LISP-MPS, una arquitectura capaz de explotar LISP para minimizar las tablas de enrutamiento intra-dominio y garantizar, entre otras, soporte para conmutación multi-protocolo y redes virtuales

Design And Analysis Of Scalable Video Streaming Systems

Despite the advancement in multimedia streaming technology, many multimedia applications are still face major challenges, including provision of Quality-of-Service (QoS), system scalability, limited resources, and cost. In this dissertation, we develop and analyze a new set of metrics based on two particular video streaming systems, namely: (1) Video-on-Demand (VOD) with video advertisements system and (2) Automated Video Surveillance System (AVS). We address the main issues in the design of commercial VOD systems: scalability and support of video advertisements. We develop a scalable delivery framework for streaming media content with video advertisements. The delivery framework combines the benefits of stream merging and periodic broadcasting. In addition, we propose new scheduling policies that are well-suited for the proposed delivery framework. We also propose a new prediction scheme of the ad viewing times, called Assign Closest Ad Completion Time (ACA). Moreover, we propose an enhanced business model, in which the revenue generated from advertisements is used to subsidize the price. Additionally, we investigate the support of targeted advertisements, whereby clients receive ads that are well-suited for their interests and needs. Furthermore, we provide the clients with the ability to select from multiple price options, each with an associate expected number of viewed ads. We provide detailed analysis of the proposed VOD system, considering realistic workload and a wide range of design parameters. In the second system, Automated Video Surveillance (AVS), we consider the system design for optimizing the subjects recognition probabilities. We focus on the management and the control of various Pan, Tilt, Zoom (PTZ) video cameras. In particular, we develop a camera management solution that provides the best tradeoff between the subject recognition probability and time complexity. We consider both subject grouping and clustering mechanisms. In subject grouping, we propose the Grid Based Grouping (GBG) and the Elevator Based P lanning (EBP) algorithms. In the clustering approach, we propose the (GBG) with Clustering (GBGC) and the EBP with Clustering (EBPC) algorithms. We characterize the impact of various factors on recognition probability. These factors include resolution, pose and zoom-distance noise. We provide detailed analysis of the camera management solution, considering realistic workload and system design parameters