1,002 research outputs found
Satellite technology : reinforcement of computer data transmission technology : implications for the maritime world communications, data transfer and maritime education
This dissertation is a study of the impact of data transmission via satellite on the maritime world of communication, data transfer and education. The aim of the study is to understand the technological reinforcement of the maritime industry and the changes taking place in it. With the avalanche of changes that are taking place in the field of information technology, they can be used to facilitate the shipping industry. This dissertation assists in understanding some of the technological evolution of satellite technology and data communication and in the needs of the maritime industry as well. This dissertation describes satellite technology and data communication and analyses the data communication software (protocols), compression software, and other application software combinations with maritime communication system provided to improve ship operation and management for safety. The conclusion and recommendations chapter examines the implications of the technology changes on developing countries, the need to be harmonised in training and education for the maritime industry, maritime communication systems and the equipment, policy of shipping companies and communication costs
On a Packet-Wise Data Transfer Monitoring System
This work tends to propose a billing system that is measured by the quality of bits/bytes transfer. In order to determine the amount of network resources to be reserved, traffic and performance descriptors must be defined. Allocated resources are used only when customers send or receive traffic, whereas when customers are inactive, resources may remain unused. Network administrators clearly prefer to charge users in proportion to the reserved resources, that is to say in proportion to the potential use of the service. In packet-wise billing system, subscribers are bill based on the actual amount of data transferred as in terms of byte. This research was carried out at unical e-library because of their facility, the researcher designed a server which serves as the billing system, in the server which is ubuntu driven, the researcher install the radius server, PHP Admin and mysql. The reason being that the radius server will do the authentication, accounting and access control, then the researcher use the packet sniffer to retrieve packet from the network using mikrotik router to connect the server and the client computer. It was discovered that when a user tries to connect to the server, it will be requested to enter a username and password that will give him/her access to the server. With this a capture will display showing that the user was successfully logged in with it bandwidth detail on it instead of time. So with this, a user can freely enjoy the service of the internet Keywords: reserved packets,, bandwidth, packet-wise billing system, processor clock timer,  weighted fair queuing, Flat rate model
InterCloud: Utility-Oriented Federation of Cloud Computing Environments for Scaling of Application Services
Cloud computing providers have setup several data centers at different
geographical locations over the Internet in order to optimally serve needs of
their customers around the world. However, existing systems do not support
mechanisms and policies for dynamically coordinating load distribution among
different Cloud-based data centers in order to determine optimal location for
hosting application services to achieve reasonable QoS levels. Further, the
Cloud computing providers are unable to predict geographic distribution of
users consuming their services, hence the load coordination must happen
automatically, and distribution of services must change in response to changes
in the load. To counter this problem, we advocate creation of federated Cloud
computing environment (InterCloud) that facilitates just-in-time,
opportunistic, and scalable provisioning of application services, consistently
achieving QoS targets under variable workload, resource and network conditions.
The overall goal is to create a computing environment that supports dynamic
expansion or contraction of capabilities (VMs, services, storage, and database)
for handling sudden variations in service demands.
This paper presents vision, challenges, and architectural elements of
InterCloud for utility-oriented federation of Cloud computing environments. The
proposed InterCloud environment supports scaling of applications across
multiple vendor clouds. We have validated our approach by conducting a set of
rigorous performance evaluation study using the CloudSim toolkit. The results
demonstrate that federated Cloud computing model has immense potential as it
offers significant performance gains as regards to response time and cost
saving under dynamic workload scenarios.Comment: 20 pages, 4 figures, 3 tables, conference pape
Performance measurement methodology for integrated services networks
With the emergence of advanced integrated services networks, the need for effective
performance analysis techniques has become extremely important. Further
advancements in these networks can only be possible if the practical performance
issues of the existing networks are clearly understood. This thesis is concerned with
the design and development of a measurement system which has been implemented on
a large experimental network.
The measurement system is based on dedicated traffic generators which have been
designed and implemented on the Project Unison network. The Unison project is a
multisite networking experiment for conducting research into the interconnection and
interworking of local area network based multi-media application systems. The traffic
generators were first developed for the Cambridge Ring based Unison network. Once
their usefulness and effectiveness was proven, high performance traffic generators
using transputer technology were built for the Cambridge Fast Ring based Unison
network. The measurement system is capable of measuring the conventional
performance parameters such as throughput and packet delay, and is able to
characterise the operational performance of network bridging components under
various loading conditions. In particular, the measurement system has been used in a
'measure and tune' fashion in order to improve the performance of a complex bridging
device.
Accurate measurement of packet delay in wide area networks is a recognised problem.
The problem is associated with the synchronisation of the clocks between the distant
machines. A chronological timestamping technique has been introduced in which the
clocks are synchronised using a broadcast synchronisation technique. Rugby time
clock receivers have been interfaced to each generator for the purpose of
synchronisation.
In order to design network applications, an accurate knowledge of the expected
network performance under different loading conditions is essential. Using the
measurement system, this has been achieved by examining the network characteristics
at the network/user interface. Also, the generators are capable of emulating a variety
of application traffic which can be injected into the network along with the traffic
from real applications, thus enabling user oriented performance parameters to be
evaluated in a mixed traffic environment.
A number of performance measurement experiments have been conducted using the
measurement system. Experimental results obtained from the Unison network serve to
emphasise the power and effectiveness of the measurement methodology
Best effort measurement based congestion control
Abstract available: p.
Design issues in quality of service routing
The range of applications and services which can be successfully deployed in packet-switched networks such as the Internet is limited when the network does nor provide Quality of Service (QoS). This is the typical situation in today's Internet. A key aspect in providing QoS support is the requirement for an optimised and intelligent mapping of customer traffic flows onto a physical network topology. The problem of selecting such paths is the task of QoS routing QoS routing algorithms are intrinsically complex and need careful study before being implemented in real networks. Our aim is to address some of the challenges present m the deployment of QoS routing methods.
This thesis considers a number of practical limitations of existing QoS routing algorithms and presents solutions to the problems identified. Many QoS routing algorithms are inherently unstable and induce traffic fluctuations in the network. We describe two new routing algorithms which address this problem The first method - ALCFRA (Adaptive Link Cost Function Routing Algorithm) - can be used in networks with sparse connectivity, while the second algorithm - CAR (Connectivity Aware Routing) - is designed to work well in other network topologies. We also describe how to ensure co-operative interaction of the routing algorithms in multiple domains when hierarchial routing is used and also present a solution to the problems of how to provide QoS support m a network where not all nodes are QoS-aware.
Our solutions are supported by extensive simulations over a wide range of network topologies and their performance is compared to existing algorithms. It is shown that our solutions advance the state of the art in QoS routing and facilitate the deployment of QoS support in tomorrow's Internet
- âŠ