Quality-of-service management in IP networks

Quality of Service (QoS) in Internet Protocol (IF) Networks has been the subject of active research over the past two decades. Integrated Services (IntServ) and Differentiated Services (DiffServ) QoS architectures have emerged as proposed standards for resource allocation in IF Networks. These two QoS architectures support the need for multiple traffic queuing systems to allow for resource partitioning for heterogeneous applications making use of the networks. There have been a number of specifications or proposals for the number of traffic queuing classes (Class of Service (CoS)) that will support integrated services in IF Networks, but none has provided verification in the form of analytical or empirical investigation to prove that its specification or proposal will be optimum. Despite the existence of the two standard QoS architectures and the large volume of research work that has been carried out on IF QoS, its deployment still remains elusive in the Internet. This is not unconnected with the complexities associated with some aspects of the standard QoS architectures. [Continues.

GUIDELINES FOR THE DESIGN OF ENHANCED, COST EFFECTIVE NETWORKS IN A MANUFACTURING ENVIRONMENT

Investigations into the transmission of real-time interactive speech over local area networks (LAN) in an industriai/commerciai environment to eventually obviate the need for a private automatic branch exchange and ultimately prepare the way for a single interactive integrated information system (PS) that provides work stations, which are networked via a LAN, with a fully interactive speech and graphics facility commensurate with the future requirements in computer integrated manufacturing (CIM). The reasons for conducting this programme of research were that existing LANs do not offer a real time interactive speech facility. Any verbal communication between workstation users on the LAN has to be carried out over a telephone network (PABX). This necessitates the provision of a second completely separate network with its associated costs. Initial investigations indicate that there is sufGcient capacity on existing LANs to support both data and real-time speech provided certain data packet delay criteria can be met. Earlier research work (in the late 1980s) has been conducted at Bell Labs and MIT. [Ref 25, 27 & 28], University of Strathclyde [Ref 24] and at BTRL [Ref 22 and 37]. In all of these cases the real time implementation issues were not fijlly addressed. In this thesis the research work reported provides the main criteria for the implementation of real-time interactive speech on both existing and newly installed networks. With such enhanced communication facilities, designers and engineers on the shop floor can be projected into their suppliers, providing a much greater integration between manufacturer and supplier which will be beneficial as Concurrent and Simultaneous Engineering Methodologies are further developed. As a result, various LANs have been evaluated as to their suitability for the transmission of real time interactive speech. As LANs, in general, can be separated into those with either deterministic or stochastic access mechanisms, investigations were carried out into the ability of both the: (i) Token Passing Bus LANs supporting the Manufacturing and Automation Protocol (MAP)—Deterministic and (u) Carrier Sense Multiple Access/Collision Detection (CSMA/CD) LANs supporting the Technical Office Protocol (TOP)— Stochastic to support real time interactive speech, as both are used extensively in commerce and manufacturing. The thesis that real time interactive speech can be transmitted over LANs employed in a computer integrated manufacturing environment has to be moderated following the tests carried out in this work, as follows:- The Token Passing LAN presents no serious problems under normal traffic conditions, however, the CSMA/CD LAN can only be used in relatively light traffic conditions i.e. below 30% of its designed maximum capacity, providing special arrangements are made to minimise the access, transmission and processing delays of speech packets. Given that a certain amount of delay is inevitable in packet switched systems (LANs), investigations have been carried out into techniques for reducing the subjective efifect of speech packet loss on real-time interactive systems due to the unacceptable delays caused by the conditions mentioned above

IP and ATM integration: A New paradigm in multi-service internetworking

ATM is a widespread technology adopted by many to support advanced data communication, in particular efficient Internet services provision. The expected challenges of multimedia communication together with the increasing massive utilization of IP-based applications urgently require redesign of networking solutions in terms of both new functionalities and enhanced performance. However, the networking context is affected by so many changes, and to some extent chaotic growth, that any approach based on a structured and complex top-down architecture is unlikely to be applicable. Instead, an approach based on finding out the best match between realistic service requirements and the pragmatic, intelligent use of technical opportunities made available by the product market seems more appropriate. By following this approach, innovations and improvements can be introduced at different times, not necessarily complying with each other according to a coherent overall design. With the aim of pursuing feasible innovations in the different networking aspects, we look at both IP and ATM internetworking in order to investigating a few of the most crucial topics/ issues related to the IP and ATM integration perspective. This research would also address various means of internetworking the Internet Protocol (IP) and Asynchronous Transfer Mode (ATM) with an objective of identifying the best possible means of delivering Quality of Service (QoS) requirements for multi-service applications, exploiting the meritorious features that IP and ATM have to offer. Although IP and ATM often have been viewed as competitors, their complementary strengths and limitations from a natural alliance that combines the best aspects of both the technologies. For instance, one limitation of ATM networks has been the relatively large gap between the speed of the network paths and the control operations needed to configure those data paths to meet changing user needs. IP\u27s greatest strength, on the other hand, is the inherent flexibility and its capacity to adapt rapidly to changing conditions. These complementary strengths and limitations make it natural to combine IP with ATM to obtain the best that each has to offer. Over time many models and architectures have evolved for IP/ATM internetworking and they have impacted the fundamental thinking in internetworking IP and ATM. These technologies, architectures, models and implementations will be reviewed in greater detail in addressing possible issues in integrating these architectures s in a multi-service, enterprise network. The objective being to make recommendations as to the best means of interworking the two in exploiting the salient features of one another to provide a faster, reliable, scalable, robust, QoS aware network in the most economical manner. How IP will be carried over ATM when a commercial worldwide ATM network is deployed is not addressed and the details of such a network still remain in a state of flux to specify anything concrete. Our research findings culminated with a strong recommendation that the best model to adopt, in light of the impending integrated service requirements of future multi-service environments, is an ATM core with IP at the edges to realize the best of both technologies in delivering QoS guarantees in a seamless manner to any node in the enterprise

Distributed multimedia systems

A distributed multimedia system (DMS) is an integrated communication, computing, and information system that enables the processing, management, delivery, and presentation of synchronized multimedia information with quality-of-service guarantees. Multimedia information may include discrete media data, such as text, data, and images, and continuous media data, such as video and audio. Such a system enhances human communications by exploiting both visual and aural senses and provides the ultimate flexibility in work and entertainment, allowing one to collaborate with remote participants, view movies on demand, access on-line digital libraries from the desktop, and so forth. In this paper, we present a technical survey of a DMS. We give an overview of distributed multimedia systems, examine the fundamental concept of digital media, identify the applications, and survey the important enabling technologies.published_or_final_versio

Integrated voice/data through a digital PBX

The digital voice/data PBX is finally reaching its anticipated potential and becoming a major factor when considering the total communications picture for many businesses today. The digital PBX has always been the choice for voice communications but has lagged behind the LAN industry when it comes to data transfers. The pendulum has begun to swing with the enhanced data capabilities of third and fourth generation PBXs. The battle for the total communication market is quite fierce between the LAN and PBX vendors now. This research thesis looks at the history, evolution, and architecture of voice/data PBXs. It traces development of PBXs through the present fourth generation architectures. From the first manual switches introduced in the late 1800\u27s through the Strowger switch, step-by-step switching, stored program control, common control, digital switches, dual bus architectures, and finally what is anticipated in the future. A detailed description of the new fourth generation dual bus architectures is presented. Lastly, speculations on the future direction PBX architectures will take is explored. A description of the mechanics of a possible Wave Division PBX is presented based on a fiber optic transport system

Experimental Evaluation of a SIP-Based Home Gateway with Multiple Wireless Interfaces for Domotics Systems

In modern houses, the presence of sensors and actuators is increasing, whilecommunication servicesandentertainment systemshad long since settled into everyday life. The utilization of wireless communication technologies, such as ZigBee, Wi-Fi, and Bluetooth, is attractive because of their short installation times and low costs. The research is moving towards the integration of the various home appliances and devices into a single domotics system, able to exploit the cooperation among the diverse subsystems and offer the end-user a single multiservice platform. In this scenario, the paper presents the experimental evaluation of a domotics framework centered on a SIP-based home gateway (SHG). While SIP is used to build a common control plane, the SHG is in charge of translating the user commands from and to the specific domotics languages. The analysis has been devoted to assess both the performance of the SHG software framework and the negative effects produced by the simultaneous interference among the three widespread wireless technologies

An investigation into the use of B-Nodes and state models for computer network technology and education

This thesis consists of a series of internationally published, peer reviewed, conference research papers and one journal paper. The papers evaluate and further develop two modelling methods for use in Information Technology (IT) design and for the educational and training needs of students within the area of computer and network technology. The IT age requires technical talent to fill positions such as network managers, web administrators, e-commerce consultants and network security experts as IT is changing rapidly, and this is placing considerable demands on higher educational institutions, both within Australia and internationally, to respond to these changes