60 research outputs found

    Post Sockets: Towards an Evolvable Network Transport Interface

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    The traditional Sockets API is showing its age, and no longer provides effective support for modern networked applications. This has led to a proliferation of non-standard extensions, alternative APIs, and workarounds that enable new features and allow applications to make good use of the network, but are difficult to use, and require expert knowledge that is not widespread. In this paper, we present Post Sockets, a proposed new standard network API, that is designed to support modern network transport protocols and features, while raising the level of abstraction and enhancing usability. Specifically, Post Sockets aims to give portable applications the ability to use a clear, messages based, interface to multi-path and multi-stream transports, rendezvous and connection racing, and fast connection re-establishment

    Tracing Internet Path Transparency

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    This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No 688421, and was supported by the Swiss State Secretariat for Education, Research and Innovation (SERI) under contract number 15.0268. The opinions expressed and arguments employed reflect only the authors’ views. The European Commission is not responsible for any use that may be made of that information. Further, the opinions expressed and arguments employed herein do not necessarily reflect the official views of the Swiss Government.Peer reviewedPublisher PD

    A path layer for the internet : enabling network operations on encrypted protocols

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    The deployment of encrypted transport protocols imposes new challenges for network operations. Key in-network functions such as those implemented by firewalls and passive measurement devices currently rely on information exposed by the transport layer. Encryption, in addition to improving privacy, helps to address ossification of network protocols caused by middleboxes that assume certain information to be present in the clear. However, “encrypting it all” risks diminishing the utility of these middleboxes for the traffic management tasks for which they were designed. A middlebox cannot use what it cannot see. We propose an architectural solution to this issue, by introducing a new “path layer” for transport-independent, in-band signaling between Internet endpoints and network elements on the paths between them, and using this layer to reinforce the boundary between the hop-by-hop network layer and the end-to- end transport layer. We define a path layer header on top of UDP to provide a common wire image for new, encrypted transports. This path layer header provides information to a transport- independent on-path state machine that replaces stateful handling currently based on exposed header flags and fields in TCP; it enables explicit measurability of transport layer performance; and offers extensibility by sender-to-path and path-to-receiver communications for diagnostics and management. This provides not only a replacement for signals that are not available with encrypted traffic, but also allows integrity-protected, enhanced signaling under endpoint control. We present an implementation of this wire image integrated with the QUIC protocol, as well as a basic stateful middlebox built on Vector Packet Processing (VPP) provided by FD.io

    Building a Standard Measurement Platform

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    Network management is achieved through a large number of disparate solutions for different technologies and parts of the end-to-end network. Gaining an overall view, and especially predicting the impact on a service user, is difficult. Recently, a number of proprietary platforms have emerged to conduct end-to-end testing from user premises; however, these are limited in scale, interoperability, and the ability to compare like-for-like results. In this article we show that these platforms share similar architectures and can benefit from the standardization of key interfaces, test definitions, information model, and protocols. We take the SamKnows platform as a use case and propose an evolution from its current proprietary protocols to standardized protocols and tests. In particular, we propose to use extensions of the IETF's IPFIX and NETCONF/YANG in the platform. Standardization will allow measurement capabilities to be included on many more network elements and user devices, providing a much more comprehensive view of user experience and enabling problems and performance bottlenecks to be identified and addressed.Publicad

    Flow Monitoring Explained: From Packet Capture to Data Analysis With NetFlow and IPFIX

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    Flow monitoring has become a prevalent method for monitoring traffic in high-speed networks. By focusing on the analysis of flows, rather than individual packets, it is often said to be more scalable than traditional packet-based traffic analysis. Flow monitoring embraces the complete chain of packet observation, flow export using protocols such as NetFlow and IPFIX, data collection, and data analysis. In contrast to what is often assumed, all stages of flow monitoring are closely intertwined. Each of these stages therefore has to be thoroughly understood, before being able to perform sound flow measurements. Otherwise, flow data artifacts and data loss can be the consequence, potentially without being observed. This paper is the first of its kind to provide an integrated tutorial on all stages of a flow monitoring setup. As shown throughout this paper, flow monitoring has evolved from the early 1990s into a powerful tool, and additional functionality will certainly be added in the future. We show, for example, how the previously opposing approaches of deep packet inspection and flow monitoring have been united into novel monitoring approaches

    Translocation of Humpback Chub into Tributary Streams of the Colorado River: Implications for Conservation of Large- River Fishes

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    The Humpback Chub Gila cypha, a large-bodied, endangered cyprinid endemic to the Colorado River basin, is in decline throughout most of its range due largely to anthropogenic factors. Translocation of Humpback Chub into tributaries of the Colorado River is one conservation activity that may contribute to the expansion of the species’ current range and eventually provide population redundancy. We evaluated growth, survival, and dispersal following translocation of approximately 900 Humpback Chub over a period of 3 years (2009, 2010, and 2011) into Shinumo Creek, a tributary stream of the Colorado River within Grand Canyon National Park. Growth and condition of Humpback Chub in Shinumo Creek were consistent among year-classes and equaled or surpassed growth estimates from both the main-stem Colorado River and the Little Colorado River, where the largest (and most stable) Humpback Chub aggregation remains. Based on passive integrated tag recoveries, 53% ( D 483/902) of translocated Humpback Chub dispersed from Shinumo Creek into the main-stem Colorado River as of January 2013, 35% leaving within 25 d following translocation. Annual apparent survival estimates within Shinumo Creek ranged from 0.22 to 0.41, but were strongly influenced by emigration. Results indicate that Shinumo Creek provides favorable conditions for growth and survival of translocated Humpback Chub and could support a new population if reproduction and recruitment occur in the future. Adaptation of translocation strategies of Humpback Chub into tributary streams ultimately may refine the role translocation plays in recovery of the species

    mPlane: an intelligent measurement plane for the internet

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    The Internet's universality is based on its decentralization and diversity. However, its distributed nature leads to operational brittleness and difficulty in identifying the root causes of performance and availability issues, especially when the involved systems span multiple administrative domains. The first step to address this fragmentation is coordinated measurement: we propose to complement the current Internet's data and control planes with a measurement plane, or mPlane for short. mPlane's distributed measurement infrastructure collects and analyzes traffic measurements at a wide variety of scales to monitor the network status. Its architecture is centered on a flexible control interface, allowing the incorporation of existing measurement tools through lightweight mPlane proxy components, and offering dynamic support for new capabilities. A focus on automated, iterative measurement makes the platform well-suited to troubleshooting support. This is supported by a reasoning system, which applies machine learning algorithms to learn from success and failure in drilling down to the root cause of a problem. This article describes the mPlane architecture and shows its applicability to several distributed measurement problems involving content delivery networks and Internet service roviders. A first case study presents the tracking and iterative analysis of cache selection policies in Akamai, while a second example focuses on the cooperation between Internet service providers and content delivery networks to better orchestrate their traffic engineering decisions and jointly improve their performance

    Are There Differences in EEG Metrics Between Younger and Older Healthy Adult When Performing Challenging Cognitive Tasks?

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    The prevalence and cost of dementia continues to rise, with the cost of treatment in the U.S. estimated at $157 billion per year (Hurd et al., 2013). Understanding cognitive function in older adults and associated brain activity could lead to the development of better prevention and treatment of dementia. Therefore, this study examined the effects of aging on brain activity, as measured by electroencephalography (EEG) in younger and older adults. EEG activity was monitored before, during, and after healthy older (70-79 years of age; N = 20) and younger adults (20-29 years of age; N = 16) completed three computerized cognitive tasks. A one way ANOVA with Bonferroni correction for multiple comparison, p \u3c 0.05, was completed to determine age effects on cognitive performance and EEG metrics. As hypothesized, younger adults performed significantly better on reasoning (Raven’s Matrices), short term memory, and inhibitory control (Stroop) tasks. The most significant age difference in the EEG metrics were higher beta amplitude, power, and relative power in older adults, a finding that is suggestive of increased anxiety. As hypothesized, the older adults exhibited lower eyes-closed theta power. However, lower eyes-open alpha amplitude and relative power in older adults was contrary to expectations. In conclusion, these otherwise healthy older adults exhibited declines in cognitive performance and suboptimal brain activity. More research is needed to determine if physical activity, meditation, or cognitive training can improve cognitive performance and brain activity
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