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.

Managing QoS in multiservice data networks

Abstract: Next-generation networks require organized methods to offer Quality of Service (QoS) guaranteed IP network connectivity. This study suggests a solution for combined control of routing and flow problems, namely an algorithm based on flow deterministic network models. The algorithm solves the problem by identifying optimal routes and triggering the flow control law only for those paths. This experiment aims to assess how QoS and MPLS traffic engineering (TE) can advance Internet performance. It also aims to ascertain avenues for Internet improvement and to devise innovative mechanisms to ensure traffic engineering provision, and Class-of-Service (CoS) features in next-generation networks. The performances of the algorithm were evaluated on a fully connected six-node network, the data for which were extracted from a realistic network

Internet Traffic Control System and Mobile Broadband Communication System in ATM Networks

MPLS is an advanced forwarding scheme which allows the network to achieve the benefits provided by traffic engineering techniques. The establishment of an end to end LSP between two IP/MPLS networks inter connected through an ATM backbone is still an open issue. This focuses in an MPLS ATM environment and address problem of provisioning a fast LSP establishment with certain QOS between 2 MPLS sub networks inter connected through an ATM backbone. The PNNI is used in ATM backbone as a routing and signaling protocol. In order to achieve the paper objectives and new PNNI elements are defined and evaluated. Voice has been the primary application in wireless network to date. However packet based application and higher bandwidth requirements to sustain these applications are ever emerging. As in wire line packet based networks while IP routing is well understood IP network by itself is still not achieved and its depart on the backbone that can offer QOS guarantee. MPLS is a newer technology that offer service information layer 2 switching and connection oriented that allows traffic engineering control traffic flows in the network. The purpose of it to show how MPLS QOS Architecture can be employed to provide traffic engineering in broadband wireless network. Keywords:  Multiservice traffic, Mobile Broadband system

Distributed Sampling for On-line SLA Assessment

New business infrastructures over the Internet pose a new set of traffic constraints. In particular, multimedia and interactive contents require guarantees of bandwidth and delivery time. The broad deployment and real-time nature of this class of applications require the provisioning of specific resources in the network to guarantee a certain level of Quality of Service (QoS). QoS techniques need ways of obtaining feedback about the status of the QoS enabled paths, for example, for checking the fulfilment of Service Level Agreements (SLA). A possible technique for obtaining such feedback is by passively monitoring the network traffic. The issue with traffic monitoring is the additional bandwidth needed by the control traffic generated by the different collection points in order to synchronise its acquired QoS metrics. Moreover, passive monitoring at line speed is an expensive process both in terms of resource consumption and price. However, some of these requirements can be significantly reduced by using traffic sampling. This paper presents a novel methodology for intra-domain on-line distributed QoS monitoring, which makes an efficient use of the network resources by employing distributed sampling mechanisms. The proposal is validated by performing real tests on an European-wide testbed. Our results show that the sampling technique can significantly reduce the traffic overhead, while obtaining very accurate estimations of the One Way Delay performance metricPostprint (published version

Network emulation focusing on QoS-Oriented satellite communication

This chapter proposes network emulation basics and a complete case study of QoS-oriented Satellite Communication

Ethernet - a survey on its fields of application

During the last decades, Ethernet progressively became the most widely used local area networking (LAN) technology. Apart from LAN installations, Ethernet became also attractive for many other fields of application, ranging from industry to avionics, telecommunication, and multimedia. The expanded application of this technology is mainly due to its significant assets like reduced cost, backward-compatibility, flexibility, and expandability. However, this new trend raises some problems concerning the services of the protocol and the requirements for each application. Therefore, specific adaptations prove essential to integrate this communication technology in each field of application. Our primary objective is to show how Ethernet has been enhanced to comply with the specific requirements of several application fields, particularly in transport, embedded and multimedia contexts. The paper first describes the common Ethernet LAN technology and highlights its main features. It reviews the most important specific Ethernet versions with respect to each application field’s requirements. Finally, we compare these different fields of application and we particularly focus on the fundamental concepts and the quality of service capabilities of each proposal

Optimal joint path computation and rate allocation for real-time traffic

Computing network paths under worst-case delay constraints has been the subject of abundant literature in the past two decades. Assuming Weighted Fair Queueing scheduling at the nodes, this translates to computing paths and reserving rates at each link. The problem is NP-hard in general, even for a single path; hence polynomial-time heuristics have been proposed in the past, that either assume equal rates at each node, or compute the path heuristically and then allocate the rates optimally on the given path. In this paper we show that the above heuristics, albeit finding optimal solutions quite often, can lead to failing of paths at very low loads, and that this could be avoided by solving the problem, i.e., path computation and rate allocation, jointly at optimality. This is possible by modeling the problem as a mixed-integer second-order cone program and solving it optimally in split-second times for relatively large networks on commodity hardware; this approach can also be easily turned into a heuristic one, trading a negligible increase in blocking probability for one order of magnitude of computation time. Extensive simulations show that these methods are feasible in today's ISPs networks and they significantly outperform the existing schemes in terms of blocking probability