Tragedy of the routing table: An analysis of collective action amongst Internet network operators

S.M. thesisThis thesis analyzes and discusses the effectiveness of social efforts to achieve collective action amongst Internet network operators in order to manage the growth of the Internet routing table. The size and rate of growth of the Internet routing table is an acknowledged challenge impeding the scalability of our BGP interdomain routing architecture. While most of the work towards a solution to this problem has focused on architectural improvements, an effort launched in the 1990s called the CIDR Report attempts to incentivize route aggregation using social forces and norms in the Internet operator community. This thesis analyzes the behavior of Internet network operators in response to the CIDR Report from 1997 to 2011 to determine whether the Report was effective in achieving this goal. While it is difficult to causally attribute aggregation behavior to appearance on the CIDR report, there is a trend for networks to improve their prefix aggregation following an appearance on the CIDR Report compared to untreated networks. This suggests that the CIDR Report did affect network aggregation behavior, although the routing table continued to grow. This aggregation improvement is most prevalent early in the study period and becomes less apparent as time goes on. Potential causes of the apparent change in efficacy of the Report are discussed and examined using Ostrom s Common Pool Resource framework. The thesis then concludes with a discussion of options for mitigating routing table growth, including the continued use of community forces to better manage the Internet routing table.S.M

Analysis of collective action amongst Internet network operators

Thesis (S.M. in Technology and Policy)--Massachusetts Institute of Technology, Engineering Systems Division, Technology and Policy Program; and, (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2011.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Cataloged from student submitted PDF version of thesis.Includes bibliographical references (p. 157-163).This thesis analyzes and discusses the effectiveness of social efforts to achieve collective action amongst Internet network operators in order to manage the growth of the Internet routing table. The size and rate of growth of the Internet routing table is an acknowledged challenge impeding the scalability of our BGP interdomain routing architecture. While most of the work towards a solution to this problem has focused on architectural improvements, an effort launched in the 1990s called the CIDR Report attempts to incentivize route aggregation using social forces and norms in the Internet operator community. This thesis analyzes the behavior of Internet network operators in response to the CIDR Report from 1997 to 2011 to determine whether the Report was effective in achieving this goal. While it is difficult to causally attribute aggregation behavior to appearance on the CIDR report, there is a trend for networks to improve their prefix aggregation following an appearance on the CIDR Report compared to untreated networks. This suggests that the CIDR Report did affect network aggregation behavior, although the routing table continued to grow. This aggregation improvement is most prevalent early in the study period and becomes less apparent as time goes on. Potential causes of the apparent change in efficacy of the Report are discussed and examined using Ostrom's Common Pool Resource framework. The thesis then concludes with a discussion of options for mitigating routing table growth, including the continued use of community forces to better manage the Internet routing table.by Stephen Robert Woodrow.S.M.S.M.in Technology and Polic

Routing and video streaming in drone networks

PhDDrones can be used for several civil applications including search and rescue, coverage, and aerial imaging. Newer applications like construction and delivery of goods are also emerging. Performing tasks as a team of drones is often beneficial but requires coordination through communication. In this thesis, the communication requirements of video streaming drone applications based on existing works are studied. The existing communication technologies are then analyzed to understand if the communication requirements posed by these drone applications can be met by the available technologies. The shortcomings of existing technologies with respect to drone applications are identified and potential requirements for future technologies are suggested. The existing communication and routing protocols including ad-hoc on-demand distance vector (AODV), location-aided routing (LAR), and greedy perimeter stateless routing (GPSR) protocols are studied to identify their limitations in context to the drone networks. An application scenario where a team of drones covers multiple areas of interest is considered, where the drones follow known trajectories and transmit continuous streams of sensed traffic (images or video) to a ground station. A route switching (RS) algorithm is proposed that utilizes both the location and the trajectory information of the drones to schedule and update routes to overcome route discovery and route error overhead. Simulation results show that the RS scheme outperforms LAR and AODV by achieving higher network performance in terms of throughput and delay. Video streaming drone applications such as search and rescue, surveillance, and disaster management, benefit from multicast wireless video streaming to transmit identical data to multiple users. Video multicast streaming using IEEE 802.11 poses challenges of reliability, performance, and fairness under tight delay bounds. Because of the mobility of the video sources and the high data-rate of the videos, the transmission rate should be adapted based on receivers' link conditions. Rate-adaptive video multicast streaming in IEEE 802.11 requires wireless link estimation as well as frequent feedback from multiple receivers. A contribution to this thesis is an application-layer rate-adaptive video multicast streaming framework using an 802.11 ad-hoc network that is applicable when both the sender and the receiver nodes are mobile. The receiver nodes of a multicast group are assigned with roles dynamically based on their link conditions. An application layer video multicast gateway (ALVM-GW) adapts the transmission rate and the video encoding rate based on the received feedback. Role switching between multiple receiver nodes (designated nodes) cater for mobility and rate adaptation addresses the challenges of performance and fairness. The reliability challenge is addressed through re-transmission of lost packets while delays under given bounds are achieved through video encoding rate adaptation. Emulation and experimental results show that the proposed approach outperforms legacy multicast in terms of packet loss and video quality

Reliable Multicast transport of the video over the WiFi network

Le transport multicast est une solution efficace pour envoyer le même contenu à plusieurs récepteurs en même temps. Ce mode est principalement utilisé pour fournir des flux multimédia en temps réel. Cependant, le multicast classique de l IEEE 802.11 n'utilise aucun mécanisme d acquittement. Ainsi, l échec de réception implique la perte définitive du paquet. Cela limite la fiabilité du transport multicast et impact la qualité des applications vidéo. Pour résoudre ce problème, 802.11v et 802.11aa sont définis récemment. Le premier amendement propose Direct Multicast Service (DMS). D'autre part, le 802.11aa introduit GroupCast with Retries (GCR). GCR définit deux nouvelles politiques de retransmission : Block Ack (BACK) et Unsolicited Retry (UR).Dans cette thèse, nous évaluons et comparons les performances de 802.11v/aa. Nos résultats montrent que tous les nouveaux protocoles multicast génèrent un overhead de transmission important. En outre, DMS a une scalabilité très limitée, et GCR-BACK n'est pas approprié pour des grands groupes multicast. D autre part, nous montrons que DMS et GCR-BACK génèrent des latences de transmission importantes lorsque le nombre de récepteurs augmente. Par ailleurs, nous étudions les facteurs de pertes dans les réseaux sans fil. Nous montrons que l'indisponibilité du récepteur peut être la cause principale des pertes importantes et de leur nature en rafales. En particulier, nos résultats montrent que la surcharge du processeur peut provoquer un taux de perte de 100%, et que le pourcentage de livraison peut être limité à 35% lorsque la carte 802.11 est en mode d économie d'énergie.Pour éviter les collisions et améliorer la fiabilité du transport multicast, nous définissons le mécanisme Busy Symbol (BS). Nos résultats montrent que BS évite les collisions et assure un taux de succès de transmission très important. Afin d'améliorer davantage la fiabilité du trafic multicast, nous définissons un nouveau protocole multicast, appelé Block Negative Acknowledgement (BNAK). Ce protocole opère comme suit. L AP envoi un bloc de paquets suivi par un Block NAK Request (BNR). Le BNR permet aux membres de détecter les données manquantes et d envoyer une demande de retransmission, c.à.d. un Block NAK Response (BNAK). Un BNAK est transmis en utilisant la procédure classique d accès au canal afin d'éviter toute collision avec d'autres paquets. En plus, cette demande est acquittée. Sous l'hypothèse que 1) le récepteur est situé dans la zone de couverture du débit de transmission utilisé, 2) les collisions sont évitées et 3) le terminal a la bonne configuration, très peu de demandes de retransmission sont envoyées, et la bande passante est préservée. Nos résultats montrent que BNAK a une très grande scalabilité et génère des délais très limités. En outre, nous définissons un algorithme d'adaptation de débit pour BNAK. Nous montrons que le bon débit de transmission est sélectionné moyennant un overhead très réduit de moins de 1%. En plus, la conception de notre protocole supporte la diffusion scalable de lavvidéo. Cette caractéristique vise à résoudre la problématique de la fluctuation de la bande passante, et à prendre en considération l'hétérogénéité des récepteurs dans un réseau sans fil.The multicast transport is an efficient solution to deliver the same content to many receivers at the same time. This mode is mainly used to deliver real-time video streams. However, the conventional multicast transmissions of IEEE 802.11 do not use any feedback policy. Therefore missing packets are definitely lost. This limits the reliability of the multicast transport and impacts the quality of the video applications. To resolve this issue, the IEEE 802.11v/aa amendments have been defined recently. The former proposes the Direct Multicast Service (DMS). On the other hand, 802.11aa introduces Groupcast with Retries (GCR) service. GCR defines two retry policies: Block Ack (BACK) and Unsolicited Retry (UR).In this thesis we evaluate and compare the performance of 802.11v/aa. Our simulation results show that all the defined policies incur an important overhead. Besides, DMS has a very limited scalability, and GCR-BACK is not appropriate for large multicast groups. We show that both DMS and GCR-BACK incur important transmission latencies when the number of the multicast receivers increases. Furthermore, we investigate the loss factors in wireless networks. We show that the device unavailability may be the principal cause of the important packet losses and their bursty nature. Particularly, our results show that the CPU overload may incur a loss rate of 100%, and that the delivery ratio may be limited to 35% when the device is in the power save mode.To avoid the collisions and to enhance the reliability of the multicast transmissions, we define the Busy Symbol (BS) mechanism. Our results show that BS prevents all the collisions and ensures a very high delivery ratio for the multicast packets. To further enhance the reliability of this traffic, we define the Block Negative Acknowledgement (BNAK) retry policy. Using our protocol, the AP transmits a block of multicast packets followed by a Block NAK Request (BNR). Upon reception of a BNR, a multicast member generates a Block NAK Response (BNAK) only if it missed some packets. A BNAK is transmitted after channel contention in order to avoid any eventual collision with other feedbacks, and is acknowledged. Under the assumption that 1) the receiver is located within the coverage area of the used data rate, 2) the collisions are avoided and 3) the terminal has the required configuration, few feedbacks are generated and the bandwidth is saved. Our results show that BNAK has a very high scalability and incurs very low delays. Furthermore, we define a rate adaptation scheme for BNAK. We show that the appropriate rate is selected on the expense of a very limited overhead of less than 1%. Besides, the conception of our protocol is defined to support the scalable video streaming. This capability intends to resolve the bandwidth fluctuation issue and to consider the device heterogeneity of the group members.BORDEAUX1-Bib.electronique (335229901) / SudocSudocFranceF

Air Traffic Management Abbreviation Compendium

As in all fields of work, an unmanageable number of abbreviations are used today in aviation for terms, definitions, commands, standards and technical descriptions. This applies in general to the areas of aeronautical communication, navigation and surveillance, cockpit and air traffic control working positions, passenger and cargo transport, and all other areas of flight planning, organization and guidance. In addition, many abbreviations are used more than once or have different meanings in different languages. In order to obtain an overview of the most common abbreviations used in air traffic management, organizations like EUROCONTROL, FAA, DWD and DLR have published lists of abbreviations in the past, which have also been enclosed in this document. In addition, abbreviations from some larger international projects related to aviation have been included to provide users with a directory as complete as possible. This means that the second edition of the Air Traffic Management Abbreviation Compendium includes now around 16,500 abbreviations and acronyms from the field of aviation

Actas del XXIV Workshop de Investigadores en Ciencias de la Computación: WICC 2022

Compilación de las ponencias presentadas en el XXIV Workshop de Investigadores en Ciencias de la Computación (WICC), llevado a cabo en Mendoza en abril de 2022.Red de Universidades con Carreras en Informátic

A ICANN entre governança e regulação : análise da atuação regulatória da ICANN nos programas de expansão dos gTLDs no Sistema de Nomes de Domínio (DNS) da Internet

Tese (doutorado)—Universidade de Brasília, Faculdade de Direito, Programa de Pós-Graduação em Direito, Doutorado em Direito, 2018.A presente tese pretende analisar a atuação da ICANN (Internet Corporation for Assigned Names and Numbers), a qual é a entidade incumbida de gerir recursos críticos da Internet, entre eles o sistema de nomes de domínio (Domain Name System – DNS), especificamente com relação à expansão do Espaço de Nomes Genéricos (gTLDs) no mencionado sistema. Após a necessária contextualização dos principais componentes da Internet, bem como o histórico de sua criação, os meios de funcionamento da ICANN e sua relação contratual com o governo dos EUA, discute-se a governança da Internet, tanto da forma realizada em fóruns internacionais quanto pela academia. A seguir, os conceitos de governança e regulação são aproximados para melhor definição e estabelecimento de distinções, com a finalidade de afirmar que a ICANN também exerce atividades regulatória. A partir da teoria processual da regulação, utilizada como marco teórica da tese, faz-se a análise de processos de autorização de novos nomes de domínio genéricos (gTLDs), tais como o “.amazon”, o “.xxx”, o “.patagonia” e o “.web”, a fim de demonstrar e avaliar o funcionamento da regulação feita pela ICANN. Em conclusão, a partir do marco teórico utilizado, verifica-se que a ICANN pode ser compreendida como um órgão regulatório e que, apesar de suas idiossincrasias, é capaz de executar uma boa política regulatória.This thesis aims to analyze the performance of the Internet Corporation for Assigned Names and Numbers – ICANN, which is the entity in charge of managing critical Internet resources, including the domain name system (DNS), specifically with respect to the expansion of the Generic Namespace (gTLDs) in the DNS. After the necessary contextualisation of the main components of the Internet, as well as the history of creation, the functioning of ICANN and its contractual relationship with the US government, it discusses Internet governance, both in the way of international forums and by the academy. Next, governance and regulation concepts are approximate for better definition and distinctions, in order to assert that ICANN also performs regulatory activities. Based on the procedural theory of regulation, used as the theoretical framework of the thesis, the processes of authorization of new generic domain names (gTLDs) such as “.amazon”, “.xxx”, “.patagonia” and “.web” in order to demonstrate and evaluate the functioning of the regulation made by ICANN. In conclusion, from the theoretical framework used, ICANN can be understood as a regulatory body and that, despite its idiosyncrasies, is capable of executing a good regulatory policy