119,171 research outputs found
Improving the performance of HTTP over high bandwidth-delay product circuits
As the WWW continues to grow, providing adequate bandwidth to countries remote from the geographic and topological center of the network, such as those in the Asia/Pacific, becomes more and more difficult. To meet the growing traffic needs of the Internet some Network Service Providers are deploying satellite connections. Through discrete event simulation of a real HTTP workload with differing international architectures this paper is able to give guidance on the architecture that should be deployed for long distance, high capacity Internet links.
We show that a significant increase in the time taken to fetch HTTP requests can be expected when traffic is moved from a long distance international terrestrial link to a satellite link. We then show several modifications to the network architecture that can be used to greatly improve the performance of a satellite link. These modifications include the use of an asymmetric satellite link, the multiplexing of multiple HTTP requests onto a single TCP connection and the use of HTTP1.1
Securely Launching Virtual Machines on Trustworthy Platforms in a Public Cloud
In this paper we consider the Infrastructure-as-a-Service (IaaS) cloud model which allows cloud users to run their own virtual machines (VMs) on available cloud computing resources. IaaS gives enterprises the possibility to outsource their process workloads with minimal effort and expense. However, one major problem with existing approaches of cloud leasing, is that the users can only get contractual guarantees regarding the integrity of the offered platforms. The fact that the IaaS user himself or herself cannot verify the provider promised cloud platform integrity, is a security risk which threatens to prevent the IaaS business in general. In this paper we address this issue and propose a novel secure VM launch protocol using Trusted Computing techniques. This protocol allows the cloud IaaS users to securely bind the VM to a trusted computer configuration such that the clear text VM only will run on a platform that has been booted into a trustworthy state. This capability builds user confidence and can serve as an important enabler for creating trust in public clouds. We evaluate the feasibility of our proposed protocol via a full scale system implementation and perform a system security analysis
DIAMOnDS - DIstributed Agents for MObile & Dynamic Services
Distributed Services Architecture with support for mobile agents between
services, offer significantly improved communication and computational
flexibility. The uses of agents allow execution of complex operations that
involve large amounts of data to be processed effectively using distributed
resources. The prototype system Distributed Agents for Mobile and Dynamic
Services (DIAMOnDS), allows a service to send agents on its behalf, to other
services, to perform data manipulation and processing. Agents have been
implemented as mobile services that are discovered using the Jini Lookup
mechanism and used by other services for task management and communication.
Agents provide proxies for interaction with other services as well as specific
GUI to monitor and control the agent activity. Thus agents acting on behalf of
one service cooperate with other services to carry out a job, providing
inter-operation of loosely coupled services in a semi-autonomous way. Remote
file system access functionality has been incorporated by the agent framework
and allows services to dynamically share and browse the file system resources
of hosts, running the services. Generic database access functionality has been
implemented in the mobile agent framework that allows performing complex data
mining and processing operations efficiently in distributed system. A basic
data searching agent is also implemented that performs a query based search in
a file system. The testing of the framework was carried out on WAN by moving
Connectivity Test agents between AgentStations in CERN, Switzerland and NUST,
Pakistan.Comment: 7 pages, 4 figures, CHEP03, La Jolla, California, March 24-28, 200
A Mobile Geo-Communication Dataset for Physiology-Aware DASH in Rural Ambulance Transport
Use of telecommunication technologies for remote, continuous monitoring of
patients can enhance effectiveness of emergency ambulance care during transport
from rural areas to a regional center hospital. However, the communication
along the various routes in rural areas may have wide bandwidth ranges from 2G
to 4G; some regions may have only lower satellite bandwidth available.
Bandwidth fluctuation together with real-time communication of various clinical
multimedia pose a major challenge during rural patient ambulance transport.;
AB@The availability of a pre-transport route-dependent communication bandwidth
database is an important resource in remote monitoring and clinical multimedia
transmission in rural ambulance transport. Here, we present a geo-communication
dataset from extensive profiling of 4 major US mobile carriers in Illinois,
from the rural location of Hoopeston to the central referral hospital center at
Urbana. In collaboration with Carle Foundation Hospital, we developed a
profiler, and collected various geographical and communication traces for
realistic emergency rural ambulance transport scenarios. Our dataset is to
support our ongoing work of proposing "physiology-aware DASH", which is
particularly useful for adaptive remote monitoring of critically ill patients
in emergency rural ambulance transport. It provides insights on ensuring higher
Quality of Service (QoS) for most critical clinical multimedia in response to
changes in patients' physiological states and bandwidth conditions. Our dataset
is available online for research community.Comment: Proceedings of the 8th ACM on Multimedia Systems Conference
(MMSys'17), Pages 158-163, Taipei, Taiwan, June 20 - 23, 201
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Prototyping a Context-Aware Framework for Pervasive Entertainment Applications
Satellite-enabled educational services specification and requirements analysis based on user feedback
Advanced tele-education services provision in remote geographically dispersed user communities (such as agriculture and maritime), based on the specific needs and requirements of such communities, implies significant infrastructural and broadband connectivity requirements for rich media, timely and quality-assured content delivery and interactivity. The solution to broadband access anywhere is provided by satellite-enabled communication infrastructures. This paper aims to present such satellite-based infrastructures that are capable of addressing the core requirements of rich media educational services in remote areas. The paper proceeds to examine a set of services that will realise such satellite-based distance learning systems and to assess the targeted usersâ interest in such services. The presented work is undertaken within the framework of the EU-funded Broadband Access Satellite Enabled Education (BASE2) project. Furthermore, requirements analysis, based on the Volere template (Robertson) and on user feedback, is undertaken
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