Performance and policy dimensions in internet routing

The Internet Routing Project, referred to in this report as the 'Highball Project', has been investigating architectures suitable for networks spanning large geographic areas and capable of very high data rates. The Highball network architecture is based on a high speed crossbar switch and an adaptive, distributed, TDMA scheduling algorithm. The scheduling algorithm controls the instantaneous configuration and swell time of the switch, one of which is attached to each node. In order to send a single burst or a multi-burst packet, a reservation request is sent to all nodes. The scheduling algorithm then configures the switches immediately prior to the arrival of each burst, so it can be relayed immediately without requiring local storage. Reservations and housekeeping information are sent using a special broadcast-spanning-tree schedule. Progress to date in the Highball Project includes the design and testing of a suite of scheduling algorithms, construction of software reservation/scheduling simulators, and construction of a strawman hardware and software implementation. A prototype switch controller and timestamp generator have been completed and are in test. Detailed documentation on the algorithms, protocols and experiments conducted are given in various reports and papers published. Abstracts of this literature are included in the bibliography at the end of this report, which serves as an extended executive summary

Communication

Machine communication - to interact not just via but also with machines - has transformed contemporary communication. It puts us not just in conversation with one another but also with our current machinery. By analyzing the alienness of this computational communication, through a close reading of interfaces and a field study of software development, this volume uncovers what it means to "communicate" today

Experimentación con relojes de alta precisión para la monitorización de tráfico en redes de ordenadores

Los operadores de redes de comunicaciones necesitan realizar una monitorización muy precisa del tráfico transportado. Ya sea para mantener la calidad necesaria en servicios en tiempo real (como por ejemplo una videoconferencia), o para poder monitorizar procesos y operaciones con alta precisión (como la necesaria en el caso del control de tráfico aéreo) necesitamos utilizar relojes de altas prestaciones que nos permitan realizar esta monitorización de la forma más precisa posible. En la primera parte de este trabajo se exponen esas necesidades, los problemas que representan y se presentan dos posibles soluciones (una basada en hardware y otra en software) para conseguir una monitorización de precisión. A continuación se analizan con detalle las soluciones propuestas y se explica cómo ponerlas en funcionamiento. Las soluciones propuestas se evalúan mediante unos escenarios de prueba con los que se pretende analizar cuál de las dos soluciones nos ofrece una mejor precisión en la monitorización del tráfico de red, así como determinar otras ventajas que nos ofrecen estas soluciones y que pueden servir para otros posibles estudios relacionados con el tema tratado en este documento. Finalmente, se presentan las conclusiones a las que hemos llegado. Por lo que hemos podido ver a raíz de las pruebas realizadas las tarjetas hardware ofrecen mejores resultados que la solución software, pese a ello, la solución software supone igualmente una mejora en la monitorización de tráfico y además es una solución mucho más barata que la solución basada en hardware. Además esta solución software ha demostrado tener unas cualidades que pueden explotarse en otros ámbitos

Communication

Contemporary communication puts us not only in conversation with one another but also with our machinery. Machine communication—to communicate not just via but also with machines—is therefore the focus of this volume. Diving into digital communications history, Finn Brunton brings to the fore the alienness of computational communication by looking at network timekeeping, automated trolling, and early attempts at communication with extraterrestrial life. Picking up this fascination with inhuman communication, Mercedes Bunz then performs a close reading of interaction design and interfaces to show how technology addresses humans (as very young children). Finally, Paula Bialski shares her findings from a field study of software development, analyzing the communicative forms that occur when code is written by separate people. Today, communication unfolds merely between two or more conscious entities but often includes an invisible third party. Inspired by this drastic shift, this volume uncovers new meanings of what it means “to communicate.

Caracterização da rede de sincronização na internet

Orientadora : Cristina Duarte MurtaDissertação (mestrado) - Universidade Federal do Paraná, Setor de Ciências Exatas, Programa de Pós-Graduação em Informática. Defesa: Curitiba, 2007Inclui bibliografiaResumo: Manter a sincronização de relógios é uma tarefa importante e complexa em sistemas distribuídos. O Network Time Protocol - NTP - é um protocolo criado para obter e manter a sincronização de relógios de computadores com o tempo real mundial. Para isto, o NTP constrói uma rede lógica dinâmica, com características de uma rede peer-to-peer, que se auto-organiza, a partir da inserção inicial dos computadores, por meio de troca freqüente de mensagens entre os pares. O NTP utiliza a Internet como meio de comunicação entre os nodos da rede NTP e é o protocolo padrão para sincronização de relógios de computadores conectados à Internet. O objetivo deste trabalho é caracterizar, sob vários aspectos, a rede de sincronização de relógios criada pelo NTP na Internet. Com dados coletados em 2005 por um robô, este trabalho apresenta uma caracterização da rede de sincronização descoberta, composta por milhares de nodos, e distribuída geograficamente por mais de 150 países e regiões do planeta. Muitos aspectos que definem a qualidade da sincronização obtida e as características topológicas da rede são apresentados e analisados. Os resultados da análise são comparados com estudos similares realizados nos últimos 15 anos, mostrando a evolução da rede de sincronização do NTP neste período. Os resultados apresentam evidências do crescimento da rede, da evolução da qualidade da sincronização e da melhoria da infra-estrutura da Internet. No entanto, alguns pressupostos do protocolo NTP podem não ser completamente atendidos na prática, o que pode prejudicar a qualidade da sincronização e limitar os resultados obtidos pelo NTP.Abstract: Clock synchronization is an important and complex task in distributed systems. The Network Time Protocol - NTP - is a protocol created to build and maintain the synchronization of computer clocks with the world real time. To do so, the NTP implements a dynamic logical network, presenting characteristics of a peer-to-peer network, which keeps itself self-organized, from the initial insertion of the computers, by means of frequent exchange of messages between peers. The NTP uses the Internet as a communication media for network nodes, and it is the standard protocol for synchronization of computer clocks connected to the Internet. The goal of this work is to characterize, in many aspects, the clock synchronization network created by the NTP in the Internet. With data collected in 2005 by a robot, this work presents a characterization of the NTP network discovered, composed by thousand of nodes, and geographically distributed in over 150 countries and regions of the planet. Many aspects that define the quality of synchronization and timekeeping and the network topological characteristics are presented and evaluated. The results of this analysis are compared to similar studies carried through in the past 15 years, showing the evolution of the NTP synchronization in this period. The results present evidences of the network growth, the evolution of the synchronization quality and the improvement in Internet infrastructure. However, some assumptions taken by the NTP protocol can be not completely taken in practical situations, harming the synchronization quality and limiting the results obtained with NTP

Utilizando software libre para un servicio de sellado digital de tiempo

El objetivo del presente trabajo es implementar una infraestructura de sellado de tiempo utilizando software libre, que cumpla con los est ándares tecnol ógicos existentes, teniendo en cuenta los requisitos necesarios para brindar un servicio 7x24. Este servicio es esencial para ser integrado con sistemas de fi rma digital, en los cuales es fundamental tener certeza del momento exacto en que se realiza cada operaci ón.Facultad de Informátic

Bolvedere: a scalable network flow threat analysis system

Since the advent of the Internet, and its public availability in the late 90’s, there have been significant advancements to network technologies and thus a significant increase of the bandwidth available to network users, both human and automated. Although this growth is of great value to network users, it has led to an increase in malicious network-based activities and it is theorized that, as more services become available on the Internet, the volume of such activities will continue to grow. Because of this, there is a need to monitor, comprehend, discern, understand and (where needed) respond to events on networks worldwide. Although this line of thought is simple in its reasoning, undertaking such a task is no small feat. Full packet analysis is a method of network surveillance that seeks out specific characteristics within network traffic that may tell of malicious activity or anomalies in regular network usage. It is carried out within firewalls and implemented through packet classification. In the context of the networks that make up the Internet, this form of packet analysis has become infeasible, as the volume of traffic introduced onto these networks every day is so large that there are simply not enough processing resources to perform such a task on every packet in real time. One could combat this problem by performing post-incident forensics; archiving packets and processing them later. However, as one cannot process all incoming packets, the archive will eventually run out of space. Full packet analysis is also hindered by the fact that some existing, commonly-used solutions are designed around a single host and single thread of execution, an outdated approach that is far slower than necessary on current computing technology. This research explores the conceptual design and implementation of a scalable network traffic analysis system named Bolvedere. Analysis performed by Bolvedere simply asks whether the existence of a connection, coupled with its associated metadata, is enough to conclude something meaningful about that connection. This idea draws away from the traditional processing of every single byte in every single packet monitored on a network link (Deep Packet Inspection) through the concept of working with connection flows. Bolvedere performs its work by leveraging the NetFlow version 9 and IPFIX protocols, but is not limited to these. It is implemented using a modular approach that allows for either complete execution of the system on a single host or the horizontal scaling out of subsystems on multiple hosts. The use of multiple hosts is achieved through the implementation of Zero Message Queue (ZMQ). This allows for Bolvedre to horizontally scale out, which results in an increase in processing resources and thus an increase in analysis throughput. This is due to ease of interprocess communications provided by ZMQ. Many underlying mechanisms in Bolvedere have been automated. This is intended to make the system more userfriendly, as the user need only tell Bolvedere what information they wish to analyse, and the system will then rebuild itself in order to achieve this required task. Bolvedere has also been hardware-accelerated through the use of Field-Programmable Gate Array (FPGA) technologies, which more than doubled the total throughput of the system

Mobilfunkbasiertes Steuerungskonzept für das Flottenmanagement in Tagebauen und Minen

Die zentrale Zielstellung dieser Arbeit ist der Entwurf eines Steuerungskonzeptes für das Flottenmanagement der mobilen Technik in Tagebauen und Minen. Dies umfasst sowohl die Analyse bestehender Systeme als auch die Formulierung von allgemeinen Systemanforderungen. Basierend auf diesen Erkenntnissen wird in der Arbeit ein Ideenkatalog skizziert, der auf den folgenden abstrakten Ansatzpunkten beruht - Mobilität, Verteilung und Kooperation der mobilen Objekte. Als integraler Bestandteil des Systems wird darauf aufbauend ein angepasstes Kommunikationskonzept entworfen. Unter Beachtung der geforderten weltweiten Einsatzfähigkeit und als Basis für eine kostengünstige Entwicklung werden neuartige Ansätze der Kombination von Lösungen aus den Bereichen Lokalisierung, Kooperation, Synchronisation, Datenerfassung und Steuerung mobiler Einheiten dargelegt