64,681 research outputs found
Government mandated blocking of foreign Web content
Blocking of foreign Web content by Internet access providers has been a hot
topic for the last 18 months in Germany. Since fall 2001 the state of
North-Rhine-Westphalia very actively tries to mandate such blocking. This paper
will take a technical view on the problems imposed by the blocking orders and
blocking content at access or network provider level in general. It will also
give some empirical data on the effects of the blocking orders to help in the
legal assessment of the orders.Comment: Preprint, revised 30.6.200
VIoLET: A Large-scale Virtual Environment for Internet of Things
IoT deployments have been growing manifold, encompassing sensors, networks,
edge, fog and cloud resources. Despite the intense interest from researchers
and practitioners, most do not have access to large-scale IoT testbeds for
validation. Simulation environments that allow analytical modeling are a poor
substitute for evaluating software platforms or application workloads in
realistic computing environments. Here, we propose VIoLET, a virtual
environment for defining and launching large-scale IoT deployments within cloud
VMs. It offers a declarative model to specify container-based compute resources
that match the performance of the native edge, fog and cloud devices using
Docker. These can be inter-connected by complex topologies on which
private/public networks, and bandwidth and latency rules are enforced. Users
can configure synthetic sensors for data generation on these devices as well.
We validate VIoLET for deployments with > 400 devices and > 1500 device-cores,
and show that the virtual IoT environment closely matches the expected compute
and network performance at modest costs. This fills an important gap between
IoT simulators and real deployments.Comment: To appear in the Proceedings of the 24TH International European
Conference On Parallel and Distributed Computing (EURO-PAR), August 27-31,
2018, Turin, Italy, europar2018.org. Selected as a Distinguished Paper for
presentation at the Plenary Session of the conferenc
A Generic Deployment Framework for Grid Computing and Distributed Applications
Deployment of distributed applications on large systems, and especially on
grid infrastructures, becomes a more and more complex task. Grid users spend a
lot of time to prepare, install and configure middleware and application
binaries on nodes, and eventually start their applications. The problem is that
the deployment process is composed of many heterogeneous tasks that have to be
orchestrated in a specific correct order. As a consequence, the automatization
of the deployment process is currently very difficult to reach. To address this
problem, we propose in this paper a generic deployment framework allowing to
automatize the execution of heterogeneous tasks composing the whole deployment
process. Our approach is based on a reification as software components of all
required deployment mechanisms or existing tools. Grid users only have to
describe the configuration to deploy in a simple natural language instead of
programming or scripting how the deployment process is executed. As a toy
example, this framework is used to deploy CORBA component-based applications
and OpenCCM middleware on one thousand nodes of the French Grid5000
infrastructure.Comment: The original publication is available at http://www.springerlink.co
Delivering Live Multimedia Streams to Mobile Hosts in a Wireless Internet with Multiple Content Aggregators
We consider the distribution of channels of live multimedia content (e.g., radio or TV broadcasts) via multiple content aggregators. In our work, an aggregator receives channels from content sources and redistributes them to a potentially large number of mobile hosts. Each aggregator can offer a channel in various configurations to cater for different wireless links, mobile hosts, and user preferences. As a result, a mobile host can generally choose from different configurations of the same channel offered by multiple alternative aggregators, which may be available through different interfaces (e.g., in a hotspot). A mobile host may need to handoff to another aggregator once it receives a channel. To prevent service disruption, a mobile host may for instance need to handoff to another aggregator when it leaves the subnets that make up its current aggregatorïżœs service area (e.g., a hotspot or a cellular network).\ud
In this paper, we present the design of a system that enables (multi-homed) mobile hosts to seamlessly handoff from one aggregator to another so that they can continue to receive a channel wherever they go. We concentrate on handoffs between aggregators as a result of a mobile host crossing a subnet boundary. As part of the system, we discuss a lightweight application-level protocol that enables mobile hosts to select the aggregator that provides the ïżœbestïżœ configuration of a channel. The protocol comes into play when a mobile host begins to receive a channel and when it crosses a subnet boundary while receiving the channel. We show how our protocol can be implemented using the standard IETF session control and description protocols SIP and SDP. The implementation combines SIP and SDPïżœs offer-answer model in a novel way
Network layer access control for context-aware IPv6 applications
As part of the Lancaster GUIDE II project, we have developed a novel wireless access point protocol designed to support the development of next generation mobile context-aware applications in our local environs. Once deployed, this architecture will allow ordinary citizens secure, accountable and convenient access to a set of tailored applications including location, multimedia and context based services, and the public Internet. Our architecture utilises packet marking and network level packet filtering techniques within a modified Mobile IPv6 protocol stack to perform access control over a range of wireless network technologies. In this paper, we describe the rationale for, and components of, our architecture and contrast our approach with other state-of-the- art systems. The paper also contains details of our current implementation work, including preliminary performance measurements
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