Quality of service support in differentiated services packet networks

During the past few years, new types of Internet applications which require performance beyond the best-effort service that is provided by the current Internet have emerged. These applications include the transmission of voice and video, which require a fixed end-to-end delay bound in order for the end-user to perceive an acceptable level of service quality. The Differentiated Services (Diffserv) model has been proposed recently to enhance the traditional best-effort service, and provide certain Quality of Serviee (QoS) guarantees to these applications. Its current definition, however, does not allow for a high level of flexibility or assurance and, therefore, it can not be widely deployed. In this paper, we introduce a new protocol for a Diffserv architecture which provides a simple and efficient solution to the above problem. It is a complete protocol, in the sense that it deals with the issues of packet scheduling, admission control, and congestion control. We will show, through experimental results, that our proposed protocol can improve the flexibility and assurance provided by current solutions, while maintaining a high level of network utilization.published_or_final_versio

Time Segmentation Approach Allowing QoS and Energy Saving for Wireless Sensor Networks

Wireless sensor networks are conceived to monitor a certain application or physical phenomena and are supposed to function for several years without any human intervention for maintenance. Thus, the main issue in sensor networks is often to extend the lifetime of the network by reducing energy consumption. On the other hand, some applications have high priority traffic that needs to be transferred within a bounded end-to-end delay while maintaining an energy efficient behavior. We propose MaCARI, a time segmentation protocol that saves energy, improves the overall performance of the network and enables quality of service in terms of guaranteed access to the medium and end-to-end delays. This time segmentation is achieved by synchronizing the activity of nodes using a tree-based beacon propagation and allocating activity periods for each cluster of nodes. The tree-based topology is inspired from the cluster-tree proposed by the ZigBee standard. The efficiency of our protocol is proven analytically, by simulation and through real testbed measurements

Uncertainty-driven Ensemble Forecasting of QoS in Software Defined Networks

Software Defined Networking (SDN) is the key technology for combining networking and Cloud solutions to provide novel applications. SDN offers a number of advantages as the existing resources can be virtualized and orchestrated to provide new services to the end users. Such a technology should be accompanied by powerful mechanisms that ensure the end-to-end quality of service at high levels, thus, enabling support for complex applications that satisfy end users needs. In this paper, we propose an intelligent mechanism that agglomerates the benefits of SDNs with real-time “Big Data” forecasting analytics. The proposed mechanism, as part of the SDN controller, supports predictive intelligence by monitoring a set of network performance parameters, forecasting their future values, and deriving indications on potential service quality violations. By treating the performance measurements as time-series, our mechanism employs a novel ensemble forecasting methodology to estimate their future values. Such predictions are fed to a Type-2 Fuzzy Logic system to deliver, in real-time, decisions related to service quality violations. Such decisions proactively assist the SDN controller for providing the best possible orchestration of the virtualized resources. We evaluate the proposed mechanism w.r.t. precision and recall metrics over synthetic data

Uncertainty-driven Ensemble Forecasting of QoS in Software Defined Networks

Software Defined Networking (SDN) is the key technology for combining networking and Cloud solutions to provide novel applications. SDN offers a number of advantages as the existing resources can be virtualized and orchestrated to provide new services to the end users. Such a technology should be accompanied by powerful mechanisms that ensure the end-to-end quality of service at high levels, thus, enabling support for complex applications that satisfy end users needs. In this paper, we propose an intelligent mechanism that agglomerates the benefits of SDNs with real-time “Big Data” forecasting analytics. The proposed mechanism, as part of the SDN controller, supports predictive intelligence by monitoring a set of network performance parameters, forecasting their future values, and deriving indications on potential service quality violations. By treating the performance measurements as time-series, our mechanism employs a novel ensemble forecasting methodology to estimate their future values. Such predictions are fed to a Type-2 Fuzzy Logic system to deliver, in real-time, decisions related to service quality violations. Such decisions proactively assist the SDN controller for providing the best possible orchestration of the virtualized resources. We evaluate the proposed mechanism w.r.t. precision and recall metrics over synthetic data

Video over Software Defined Networking

poster abstractSupporting end-to-end quality of service (QoS) for video applications requires the network to select optimum path among multiple paths to improve application performance. Multiple network paths from source to destination may be available but due to current network high coupling design identifying alternate paths is difficult. Network architecture, like Integrated services (IntServ), install a single path from source to destination which may not be optimum path for the application. Furthermore, it is an arduous task for video application developers to request service from IntServ. This paper provides three contributions to research on providing end-to-end QoS for video applications. First, it presents video over software defined networking (VSDN) - an architecture that is capable of making optimum path selection utilizing a global network view. Second, it describes the VSDN protocol used by video application developers to request service from VSDN enabled networks. Third, it presents the results of implementing a prototype of VSDN and quantitatively evaluates its behavior. The results show that VSDN has a linear-message complexity

Design and prototype of a train-to-wayside communication architecture

Telecommunication has become very important in modern society and seems to be almost omnipresent, making daily life easier, more pleasant and connecting people everywhere. It does not only connect people, but also machines, enhancing the efficiency of automated tasks and monitoring automated processes. In this context the IBBT (Interdisciplinary Institute for BroadBand Technology) project TRACK (TRain Applications over an advanced Communication networK), sets the definition and prototyping of an end-to-end train-to-wayside communication architecture as one of the main research goals. The architecture provides networking capabilities for train monitoring, personnel applications and passenger Internet services. In the context of the project a prototype framework was developed to give a complete functioning demonstrator. Every aspect: tunneling and mobility, performance enhancements, and priority and quality of service were taken into consideration. In contrast to other research in this area, which has given mostly high-level overviews, TRACK resulted in a detailed architecture with all different elements present

Designing a High-Quality Network: An Application-Oriented Approach

As new computer network technologies emerge, the application designers and the application users expect an increasing level of quality of service from them. Hence, it is a common practice in the newer technologies to provide more Quality of Service (QoS) components. Until now, these QoS solutions have been both network-technology specific and network-oriented solutions. In this thesis, we present an application-oriented approach to design a high quality network which is independent of the underlying communication technology. In this thesis, we propose a QoS architecture to provide predictable performance to the end-to-end application users in a high quality networking environment. In our architecture, QUANTA (Quality of Service Architecture for Native TCP/IP over ATM networks), we integrate different application requirements and different existing native QoS architectures into a single end-to-end architecture. Through experimentation we identify the architectural issues and the different QoS components required. We propose solutions which include isolation of the applications and managing the knowledge of the applications. The issue of isolating an application is subdivided into classification and identification of the applications. In addressing these issues we propose a ripple-through classification mechanism and a Generic Soft State (GSS) identification mechanism. To manage the knowledge of the applications we propose different QoS components, such as a GSS negotiation mechanism, a GSS communication mechanism and a GSS monitoring mechanism (such as GSS Relays and GSS Agents). QUANTA\u27s overhead is measured by running applications with different life-times and QoS requirements with and without QUANTA. For a transaction-oriented applications, the overhead induced by using QUANTA is larger than the benefit of using QUANTA. In high data rate applications and in long life time applications, a predictable performance to the applications is achieved with very low overhead by QUANTA. We demonstrate that QUANTA can manage and maintain Quality of Service for different classes of applications under varying host and network load conditions transparent to the application user. Using QUANTA, we can reach nearly 80% of the channel utilization under loaded conditions, whereas without QUANTA, the load on the network can reduce the channel utilization to 40%. Quanta has reduced a 350 msec delay under loaded conditions to less than a 10 msec delay. With the exception of short transition periods, QUANTA can sustain throughput to within the bounds of the specification of the user. We identify the limitations of QUANTA as currently proposed and discuss possible enhancements to it and other such architectures to remedy these limitations