1 - The Big Picture

The current World Wide Web service model treats all requests equivalently, both while being processed by servers and while being transmitted over the network. For some uses, such as Web prefetching or multiple priority schemes, different levels of service are desirable. This paper presents three simple, server-side, application-level mechanisms (limiting process pool size, lowering process priorities, limiting transmission rate) to provide two different levels of Web service (regular and low priority). We evaluated the performance of these mechanisms under combinations of two foreground workloads (light and heavy) and two levels of available network bandwidth (10 Mb/s and 100 Mb/s). Our experiments show that even with background traffic sufficient to saturate the network, foreground performance is reduced by at most 4–17%. Thus, our user-level mechanisms can effectively provide different service classes even in the absence of operating system and network support.

Connection management for QoS service on the Web

Wavelength division multiplexing/time division multiplexing (WDM/TDM) passive optical networks (PON) is being viewed as a promising solution for delivering multiple services and applications. The hybrid WDM / TDM PON uses the wavelength and bandwidth allocation strategy to control the distribution of the wavelength channels in the uplink direction, so that it can ensure the high bandwidth requirements of multiple Optical Network Units (ONUs) while improving the wavelength resource utilization. Through the investigation of the presented dynamic bandwidth allocation algorithms, these algorithms can't satisfy the requirements of different levels of service very well while adapting to the structural characteristics of mixed WDM / TDM PON system. This paper introduces a novel wavelength and bandwidth allocation algorithm to efficiently utilize the bandwidth and support QoS (Quality of Service) guarantees in WDM/TDM PON. Two priority based polling subcycles are introduced in order to increase system efficiency and improve system performance. The fixed priority polling subcycle and dynamic priority polling subcycle follow different principles to implement wavelength and bandwidth allocation according to the priority of different levels of service. A simulation was conducted to study the performance of the priority based polling in dynamic resource allocation algorithm in WDM/TDM PON. The results show that the performance of delay-sensitive services is greatly improved without degrading QoS guarantees for other services. Compared with the traditional dynamic bandwidth allocation algorithms, this algorithm can meet bandwidth needs of different priority traffic class, achieve low loss rate performance, and ensure real-time of high priority traffic class in terms of overall traffic on the network.

The study presented in this paper aims to quantify the impact of level of service on real time crash risks on freeways and to investigate the mechanisms of crash occurrences in different level of service. Using crash data and paired traffic data extracted from a northbound segment of the I-880 freeway in the United States, a conditional logit model is conducted to relate the crash risks to levels of service. It is found that LOS E had the greatest impact on crash occurrences on freeways, followed by LOS F and LOS D, and the crash risks associated with LOS B are not significantly different from those associated with LOS A. The random forest algorithm is further conducted to identify the contributing factors to crash occurrence in different LOS. The findings of random forest demonstrate that the mechanisms of crash occurrence are quite different across different levels of service. The vehicle platoon and abrupt change in vehicle speed contribute to the crash risks in LOS A and B. In LOS C or LOS D, lane changes have impacts on crash risks, and the high crash risks associated with LOS E are mainly caused by high traffic volumes and oscillating traffic conditions. The findings of this study suggests that different traffic management strategies should be developed in dynamic freeway traffic management systems based on the contributing factors to crash occurrences in different levels of service.

Introduction: Children and young people (CYP) with medical complexity, have high levels of healthcare needs and utilisation, representing 10% of patients attending children’s hospitals, and accounting for 60% of healthcare expenditure in the state of New South Wales (NSW), Australia. Furthermore, 30% of children in NSW live outside major cities and require enhanced local health solutions to manage healthcare needs, reduce travel and family disruptions and limit out-of-pocket expenses. The Rural Kids Guided Personalised Service (RuralKidsGPS) is a co-designed innovative integrated model of care coordination for CYP living with medical complexity, modelled on the successfully implemented and sustained KidsGPS program in tertiary children’s hospitals in Sydney. RuralKidsGPS is being implemented into four rural local health districts (LHDs) across NSW. This study explores early implementation barriers and enablers to inform contextual adaption and ensure scalability across diverse health settings. Methods: The implementation evaluation is informed by qualitative methods using semi-structured interviews and focus groups, with children and families, healthcare providers embedded researchers, and health service managers. Adopting an inductive approach underpinned by the Consolidated Framework for Implementation Research (CFIR), we identify implementation strategies, barriers and enablers influencing adoption, delivery, and sustainability of RuralKidsGPS. In this early phase of implementation evaluation (6-12 month after commencement) we have focused on implementation outcomes based on Proctor’s framework, including acceptability, appropriateness, adaptability, fidelity, and feasibility. Results: The interviews demonstrated the variations in setting and context across the LHDs and the adaption of RuralKidsGPS to meet local needs. Different levels of service demand, the time required for engagement with families from diverse socio-economic and cultural backgrounds and different levels of pre-existing service, and staff changes, contribute to the complexity of service implementation and delivery. All four LHDs share borders with jurisdictions outside of NSW, resulting in some children traveling across state or territory borders to access specialist health services. The complexities of sharing and gaining access to healthcare information across jurisdictions has impacted the timely delivery of care coordination and shared care plan development. RuralKidsGPS builds local healthcare capacity to manage CYP living with medical complexity but requires commitment and effort to build relationships with established local services and understanding of processes, and values, whilst conserving local resources. The perceived value and commitment to RuralKidsGPS by nurse care coordinators who leverage local knowledge and networks to deliver family-centred care, is a key enabler. Importantly, reciprocal support from health managers and health care professionals, and access to resources and networks is providing nurse coordinators the power to adapt and implement RuralKidsGPS. During this period, all LHDs were impacted by natural disasters (floods, bushfires) and COVID-19 creating barriers that required those implementing the RuralKidsGPS to flex and adapt. Conclusion: Early findings highlight the importance of adaptation to local contexts, the challenges and barriers and the resilience of the care coordinators implementing RuralKidsGPS. Care coordination enables families to navigate fragmented, complex health care systems, more efficiently and effectively. This research will inform the development of an implementation guide to support scaling and sustaining similar models of paediatric integrated care.

Service providers have been in the process of evaluating and evolving their multiple networks to a single converged Internet Protocol (IP)-based infrastructure upon which they will deploy existing and future services. Although many approaches have been proposed, provisioning of Quality of Service (QoS) in the IP-based networks is still a challenging task. From the evolution of QoS solutions, Differentiated Services (DiffServ) appears to become the mainstream QoS solution. Using service differentiation principle, DiffServ approach for providing QoS omits the integration with other traffic control mechanisms. Multi-Protocol Label Switching (MPLS) complements DiffServ providing mechanisms to choose and reserve resources on the best available path for a given traffic. This paper discusses the MPLS DiffServ integration to achieve QoS in IP-based networks and to illustrate its effectiveness by performing a simulation using Network Simulator (ns-2).

In conventional TCP/IP networks, there is a differentiated service architecture for providing different levels of services. Similarly in Delay Tolerant Networks (DTNs), we need to provide differentiated services where the network resources are limited, particularly in buffer size. Since DTNs have their own network characteristics, such as multiple copy routings, and intermittently connection, the traditional differentiated service architecture does not apply. In this paper, we propose two simple schemes to provide a packet forwarding assurance in DTNs. The two proposed schemes are an absolute differentiation scheme, and a relative differentiation scheme. These schemes have a prioritization process when a packet is dropped from the local buffer at each node to provide a high priority to Assured Forwarding (AF) packet and a low priority to Best Effort packet. We show that the proposed algorithms can dynamically find the appropriate target delivery ratio for AF packets, which can provide forwarding assurance for AF packets while avoiding starvation of BE packets, without any global information even though network conditions are changing. We believe that our study is the initial step toward exploiting differentiation services in DTNs.

Recent advancements in Multi-Protocol Label Switching (MPLS) based technology has brought transformation in next generation computer networking by enhancing Traffic Engineering (TE) features and Quality of Service (QoS) service parameters. Nowadays traffic management is successfully controlled by MPLS technology especially in case of underutilized or over-utilized links. The main dissimilarity between Internet Protocol (IP) and MPLS lies in the complexity of routing or switching look-up tables that seem to be less complex in latter type of networks. MPLS network tunneling is relied on a QoS routing algorithm thereby establishing a bandwidth guaranteed and less delay paths from source to destination. In this paper, a hybrid algorithm named Hybrid MPLS Tunneling Algorithm (HMTA) which comprises of bandwidth and delay differentiation techniques as well as on the basis of priority bits contained in each data packet is proposed which improves QoS routing of MPLS networks. In proposed algorithm, the differentiation of links is based on the threshold values of bandwidth and delay which is also named as the link state information. The link differentiation is done to reduce the blocking probability and number of times QoS state exchangestake place resulting in increment of QoS overheads. In order to improve the performance, this new approach is using high priority bits to accurately transmit the data-labeled or content-labeled packets to its destination by using the simulation tool MATLAB to perform the experiments. Finally, the simulation experiments demonstrate that proposed approach results in less blocking probability, high utilized bandwidth, lower packet loss, high network utilization with minimal delay.

Users have become used to accepting two unfortunate consequences of complying with requests to supply personal data to service providers. Firstly, the personal data that a user supplies becomes the property of the service provider, which means that the data subject loses control over what is subsequently done with their data. Secondly, provision of services is made on an “all or nothing” basis, being dependent upon the user supplying all the personal data requested by a service or forgoing use of that service entirely. We present an approach to personal data management which avoids these two unnecessary disadvantages. Personal Data Stores enable individuals to retain ownership and control of their personal data, granting service providers access to specific items of that data upon request whilst remaining the owners of their data. Trusted third parties will be required to curate the data in order to ensure that it is non-repudiatable. Privacy Policy Negotiation will enable data subjects to negotiate with service providers about how much of their personal data they disclose and how detailed that data is. Different levels of service can be provided depending on what personal data a user is prepared to disclose. In this paper we describe systems and algorithms for Personal Data Stores and Privacy Policy Negotiation which have been implemented and tested separately and show how they can be combined to the benefit of data subjects.

Chapter 8 - GMPLS and Traffic Engineering

The combined use of the differentiated services (DiffServ) and multiprotocol label switching (MPLS) technologies is envisioned to provide guaranteed quality of service (QoS) for multimedia traffic in IP networks. One of the most attractive applications of MPLS is traffic engineering (TE), However, MPLS by itself cannot provide service differentiation, which brings up the need to complement it with another technology capable of providing such a feature: DiffServ. By mapping the traffic from different DiffServ classes of service on separate LSPs(light switched paths) networks can meet engineering constraints specific to the given class on both shortest and non-shortest path. This TE strategy is called DiffServ-aware TE (DS-TE). The experimental results caculated in this paper plot the efficiency of GMPLS/Lightwave Agile Switching Simulator (GLASS) as a network manager in different and unpredictable traffic conditions at the expense of a limited increase in the computational complexity and cost.

The widespread diffusion of distributed services, providing access to resources through the Net, has stressed the need of secure ways to authenticate users. The heterogeneity of resources leads to different authentication mechanisms implementations often requiring multiple log-on actions also in intra-domain multi-services scenario. The article presents a roadmap on authentication mechanisms implemented at different levels of services’ software structure.

A new traffic engineering manager for DiffServ/MPLS networks: design and implementation on an IP QoS Testbed

Internet traffic engineering using multi-protocol label switching (MPLS)

The transport infrastructure to VoIP traffic is moving toward a multiple service platform of high-speed routers interconnected by optical network SDH/WDM. A multiple-service network allows operators to attend to clients through optimization of resources, differentiated quality of service and traffic engineering. This article describes a scalable architecture for the transport of IP telephony services based on MPLS and DiffServ as complementary solutions to provide QoS in access, collector portion, and core of the network. This work presents the state of the art of the protocols related with quality of service, routing and traffic engineering in the IP Telephony field. First we examine the network elements and their functionality inside each protocol, with a focus on the environment of the two workgroups, ITU-T and IETF. Finally we discuss the necessary changes for the introduction of MPLS (Multi Protocol Label Switching) as a significant strategy for the transport of IP telephony services, due to its capacity to emulate the orientation to connection provided by ATM technology. Moreover it offers scalability, low cost, and the possibility of automatization of several aspects of the traffic engineering function - such as the bearer capacity for VoIP, thereby providing more predictable, and even constrained QoS.