Managing Bandwidth and Traffic via Bundling and Filtration in Large-Scale Distributed Simulations

Research has shown that bandwidth can be a limiting factor in the performance of distributed simulations. The Air Force\u27s Distributed Mission Operations Center (DMOC) periodically hosts one of the largest distributed simulation events in the world. The engineers at the DMOC have dealt with the difficult problem of limited bandwidth by implementing application level filters that process all DIS PDUs between the various networks connected to the exercise. This thesis examines their implemented filter and proposes: adaptive range-based filtering and bundling together of PDUs. The goals are to reduce the number of PDUs passed by the adaptive filter and to reduce network overhead and the total amount of data transferred by maximizing packet size up to the MTU. The proposed changes were implemented and logged data from previous events were used on a test network in order to measure the improvement from the base filter to the improved filter. The results showed that the adaptive range based filter was effective, though minimally so, and that the PDU bundling resulted in a reduction of 17% to 20% of the total traffic transmitted across the network

Exploring the benefits of multipath TCP In wireless networks

The revolution of the information society has created a completely new situation in the telecommunications markets. As the average user data demands in today's society grow bigger, since users nowadays are demanding a faster, wider and more reliable communication service from the operators so they can watch more videos, listen to more music or access the Internet in general with a better quality, a lower latency and seamlessly to the network access they are using, the network operators face the challenge to fit this demands into their existing networks. This has forced the operators to think in terms of how optimal they are on providing their services if they want to fulfil the customer requirements in this new environment. At the same time we need to keep in mind that simultaneously to this new user's habits smartphones revolution has created, it has also made it possible to have accessible communication devices which have the necessary hardware and horsepower to keep different network interfaces up, and so it has become a common thing to reach the Internet via different kind of networks along the day. Even more it has enabled a rich communications environment where different connection possibilities are available to the user at the same time. In this context, the idea of multipath communication emerges. The idea of taking advantage of a dense wireless communication offer through the use of multipath (sending and receiving information through different network interfaces simultaneously) looks promising to overcome a situation where user's communications services demand grows and at the same time the mobile network load becomes stronger. The newfangled protocol Multipath TCP (MPTCP) is a technology which is enabling in practice this king of multipath communication, and it is the focus of this project to dig into possible benefits the protocol may bring to the table by defining a set of use cases, test-bed implementations and experiments with MPTCP which we present and analyse in this document.La revolución de la sociedad de la información ha creado una situación que es completamente nueva en los mercados de telecomunicaciones. A medida que el usuario medio aumenta su demanda de datos, ya que hoy en día los hábitos de estos pasan por conexiones más rápidas y fiables que les permitan reproducir contenido (video, música, páginas web) con mejor calidad, menor latencia y transparentemente a la red que estén utilizando, los operadores de red afrontan nuevos retos a la hora de encajar estas expectativas del usuario dentro de las posibilidades que ofrece la red. Esto está forzando a los operadores a buscar una manera más óptima de gestionar el tráfico de sus clientes para así poder satisfacer la demanda de unos servicios de mayor calidad que estos realizan. Al mismo tiempo hay que tener en mente que, de la misma manera que el impacto que esta esta revolución de los smartphones ha tenido en los hábitos de consumo del usuario ha creado nuevos y complejos problemas, también ha hecho posible que existan dispositivos económicamente accesibles para el público con el hardware y la capacidad de procesamiento necesarias para incorporar múltiples adaptadores de red, y esto a su vez ha llevado a al escenario actual en el que comúnmente coexisten en el mismo lugar diferentes posibilidades para conectarse a internet (típicamente Wi-Fi y conexión móvil, pero también podríamos nombrar tecnologías como el Bluetooth o la clásica conexión de Ethernet en ordenadores portátiles) Es en este contexto en el que surge la idea de la comunicación multi-trayecto. La idea de aprovechar un entorno con una densa pero heterogénea oferta de conexión a través del uso del multi-trayecto (enviar y recibir información a través de múltiples interfaces de red simultáneamente) aparece como una posibilidad prometedora para los operadores para mejorar la experiencia del usuario al mismo tiempo que se gestiona el tráfico en la red de una manera más eficiente. El protocolo experimental Multipath TCP es una extensión del TCP clásico que hace posible este uso simultáneo de múltiples interfaces para la comunicación, y es objetivo de este proyecto diseñar, implementar y testear el protocolo en diferentes casos de uso en los que el multi-trayecto ofrece, a priori, algunas ventajas. En las siguientes páginas explicaremos que casos de uso hemos elegido para probar el protocolo y por qué, cómo hemos diseñado e implementado los bancos de pruebas y que resultados hemos obtenido en nuestro experimentos sobre el rendimiento del protocolo, realizando al mismo tiempo un análisis crítico de los resultados de los resultados.Ingeniería de Telecomunicació

Multipath Traffic Bundling with Firefox OS

The current document describes the process of development and analysis of the setup for traffic bundling on a Firefox OS environment. Chapter 2 introduces the technology and features that were involved in the project. In Chapter 3, the development is described, with details of the implementation of the different features. Chapter 4 presents the tests that were carried out and analyzes the results obtained. Chapter 5 contains the summary of the document and a personal overview of the project.Ingeniería de Telecomunicació

NUMA impact on network storage protocolsover high-speed raw Ethernet

Proceedings of: Second International Workshop on Sustainable Ultrascale Computing Systems (NESUS 2015). Krakow (Poland), September 10-11, 2015.Current storage trends dictate placing fast storage devices in all servers and using them as a single distributed storage system. In this converged model where storage and compute resources co-exist in the same server, the role of the network is becoming more important: network overhead is becoming a main imitation to improving storage performance. In our previous work we have designed Tyche, a network protocol for converged storage that bundles multiple 10GigE links transparently and reduces protocol overheads over raw Ethernet without hardware support. However, current technology trends and server consolidation dictates building servers with large amounts of resources (CPU, memory, network, storage). Such servers need to employ Non-Uniform Memory Architectures (NUMA) to scale memory performance. NUMA introduces significant problems with the placement of data and buffers at all software levels. In this paper, we first use Tyche to examine the performance implications of NUMA servers on end-to-end network storage performance. Our results show that NUMA effects have significant negative impact and can reduce throughput by almost 2x on servers with as few as 8 cores (16 hyper-threads). Then, we propose extensions to network protocols that can mitigate this impact. We use information about the location of data, cores, and NICs to properly align data transfers and minimize the impact of NUMA servers. Our design almost entirely eliminates NUMA effects by encapsulating all protocol structures to a “channel” concept and then carefully mapping channels and their resources to NICs and NUMA nodes.We thankfully acknowledge the support of the European Commission under the 7th Framework Programs through the NanoStreams (FP7-ICT-610509) project, the HiPEAC3 (FP7-ICT-287759) Network of Excellence, and the COST programme Action IC1305, ’Network for Sustainable Ultrascale Computing (NESUS)’

Web Content Delivery Optimization

Milliseconds matters, when they’re counted. If we consider the life of the universe into one single year, then on 31 December at 11:59:59.5 PM, “speed” was transportation’s concern, and now after 500 milliseconds it is web’s, and no one knows whose concern it would be in coming milliseconds, but at this very moment; this thesis proposes an optimization method, mainly for content delivery on slow connections. The method utilizes a proxy as a middle box to fetch the content; requested by a client, from a single or multiple web servers, and bundles all of the fetched image content types that fits into the bundling policy; inside a JavaScript file in Base64 format. This optimization method reduces the number of HTTP requests between the client and multiple web servers as a result of its proposed bundling solution, and at the same time optimizes the HTTP compression efficiency as a result of its proposed method of aggregative textual content compression. Page loading time results of the test web pages; which were specially designed and developed to capture the optimum benefits of the proposed method; proved up to 81% faster page loading time for all connection types. However, other tests in non-optimal situations such as webpages which use “Lazy Loading” techniques, showed just 35% to 50% benefits, that is only achievable on 2G and 3G connections (0.2 Mbps – 15 Mbps downlink) and not faster connections

A Survey on the Path Computation Element (PCE) Architecture

Quality of Service-enabled applications and services rely on Traffic Engineering-based (TE) Label Switched Paths (LSP) established in core networks and controlled by the GMPLS control plane. Path computation process is crucial to achieve the desired TE objective. Its actual effectiveness depends on a number of factors. Mechanisms utilized to update topology and TE information, as well as the latency between path computation and resource reservation, which is typically distributed, may affect path computation efficiency. Moreover, TE visibility is limited in many network scenarios, such as multi-layer, multi-domain and multi-carrier networks, and it may negatively impact resource utilization. The Internet Engineering Task Force (IETF) has promoted the Path Computation Element (PCE) architecture, proposing a dedicated network entity devoted to path computation process. The PCE represents a flexible instrument to overcome visibility and distributed provisioning inefficiencies. Communications between path computation clients (PCC) and PCEs, realized through the PCE Protocol (PCEP), also enable inter-PCE communications offering an attractive way to perform TE-based path computation among cooperating PCEs in multi-layer/domain scenarios, while preserving scalability and confidentiality. This survey presents the state-of-the-art on the PCE architecture for GMPLS-controlled networks carried out by research and standardization community. In this work, packet (i.e., MPLS-TE and MPLS-TP) and wavelength/spectrum (i.e., WSON and SSON) switching capabilities are the considered technological platforms, in which the PCE is shown to achieve a number of evident benefits

Data Transmission Scheduling For Distributed Simulation Using Packet A

Communication bandwidth and latency reduction techniques are developed for Distributed Interactive Simulation (DIS) protocols. Using logs from vignettes simulated by the OneSAF Testbed Baseline (OTB), a discrete event simulator based on the OMNeT++ modeling environment is developed to analyze the Protocol Data Unit (PDU) traffic over a wireless flying Local Area Network (LAN). Alternative PDU bundling and compression techniques are studied under various metrics including slack time, travel time, queue length, and collision rate. Based on these results, Packet Alloying, a technique for the optimized bundling of packets, is proposed and evaluated. Packet Alloying becomes more active when it is needed most: during negative spikes of transmission slack time. It produces aggregations that preserve the internal PDU format, allowing the resulting packets to be subjectable to further bundling and/or compression by conventional techniques. To optimize the selection of bundle delimitation, three online predictive strategies were developed: Neural-Network based, Always-Wait, and Always-Send. These were compared with three offline strategies defined as Type, Type-Length and Type-Length-Size. Applying Always-Wait to the studied vignette using the wireless links set to 64 Kbps, a reduction in the magnitude of negative slack time from -75 to -9 seconds for the worst spike was achieved, which represents a reduction of 88 %. Similarly, at 64 Kbps, Always-Wait reduced the average satellite queue length from 2,963 to 327 messages for a 89% reduction. From the analysis of negative slack-time spikes it was determined which PDU types are of highest priority. The router and satellite queues in the case study were modified accordingly using a priority-based transmission scheduler. The analysis of total travel times based of PDU types numerically shows the benefit obtained. The contributions of this dissertation include the formalization of a selective PDU bundling scheme, the proposal and study of different predictive algorithms for the next PDU, and priority-based optimization using Head-of-Line (HoL) service. These results demonstrate the validity of packet optimizations for distributed simulation environments and other possible applications such as TCP/IP transmissions