Providing Quality of Service across Multiple Providers

In this chapter, the authors present some of the latest developments related to the provisioning of Quality of Service (QoS) in today’s networks and the associated network management structures that are or will be deployed to support them. They first give a brief overview of the most important Quality of Service proposals in the areas of Layer 2 (L2) and Layer 3 (L3) QoS provisioning in backbone networks, and they discuss the network management structures and brokers that have been proposed in order to implement these services. As a case study, they describe the pan-european research and academic network, which is supported centrally by GEANT and which encompasses multiple independent NRENs (National Research and Education Networks). In the last few years, GEANT has developed and deployed a number of production and pilot services meant for the delivery of quality network services to the end users across Europe.

Scalable Intra and Inter Domain IPv6 QoS Management and Pricing Scheme

Network multimedia applications constitute a large part of Internet traffic and guaranteed delivery of such traffic is a challenge because of their sensitivity to delay, packet loss and higher bandwidth requirement. The need for guaranteed traffic delivery is exacerbated by the increasing delay experienced by traffic propagating through more than one QoS domain. Hence, there is a need for a flexible and a scalable QoS manager that handles and manages the needs of traffic flows throughout multiple IPv6 domains. The IPv6 QoS manager, presented in this paper, uses a combination of the packets’ flow ID and the source address (Domain Global Identifier (DGI)), to process and reserve resources inside an IPv6 domain. To ensure inter-domain QoS management, the QoS domain manager should also communicate with other QoS domains’ managers to ensure that traffic flows are guaranteed delivery. In this scheme, the IPv6 QoS manager handles QoS requests by either processing them locally if the intended destination is located locally or forwards the request to the neighboring domain’s QoS manager. End-to-end QoS is achieved with an integrated admission and management unit. The feasibility of the proposed QoS management scheme is illustrated for both intra- and inter-domain QoS management. The scalability of the QoS management scheme for inter-domain scenarios is illustrated with simulations for traffic flows propagating through two and three domains. Excellent average end-to-end delay results have been achieved when traffic flow propagates through more than one domain. Simulations show that packets belonging to non-conformant flows experience increased delay, and such packets are degraded to lower priority if they exceed their negotiated traffic flow rates. Many pricing schemes have been proposed for QoS-enabled networks. However, integrated pricing and admission control has not been studied in detail. A dynamic pricing model is integrated with the IPv6 QoS manager to study the effects of increasing traffic flows rates on the increased cost of delivering high priority traffic flows. The pricing agent assigns prices dynamically for each traffic flow accepted by the domain manager. Combining the pricing strategy with the QoS manager allows only higher priority traffic packets that are willing to pay more to be processed during congestion. This approach is flexible and scalable as end-to-end pricing is decoupled from packet forwarding and resource reservation decisions. Simulations show that additional revenue is generated as prices change dynamically according to the network congestion status.

Traffic and Network Performance Monitoring for Effective Quality of Service and Network Management

The authors consider distributed mobile networks carrying time-varying heterogeneous traffics. To deal effectively with the mobile and time-varying distributed environment, the deployment of traffic and network performance monitoring techniques is necessary for the identification of traffic changes, network failures, and also for the facilitation of protocol adaptations and topological modifications. Concurrently, the heterogeneous traffic environment necessitates the deployment of hybrid information transport techniques. This chapter discusses the design, analysis, and evaluation of distributed and dynamic techniques which manage the traffic and monitor the network performance effectively, while capturing the dynamics inherent in the mobile heterogeneous environments. Specifically, the design of a monitoring sub-network is sought, where the arising research tasks include: • the adoption of a core sequential algorithm which monitors both the variations in the rates of the information data flows and the dynamics of the network performance. • The identification of the specific operational and performance characteristics of the monitoring systems, when the core algorithm is implemented in a distributed environment; for a given network topology, it is important to identify the minimum size monitoring sub-network for complete “visibility” of data flows and network functions. • Dynamically changing monitoring sub-network architectures, as functions of time-varying network topologies. • The deployment of Artificial Intelligence learning techniques, in the presence of dynamically changing network and information flow environments, to appropriately adapt crucial operational parameters of the data monitoring algorithms.

Traffic Controller for Handling Service Quality in Multimedia Network

The present day Internet traffic largely caters for the multimedia traffic throwing open new and unthinkable applications such as tele-surgery. The complexity of data transactions increases with a demand for in time and real time data transfers, demanding the limited resources of the network beyond their capabilities. It requires a prioritization of data transfers, controlled dumping of data over the network etc. To make the matter worse, the data from different origin combine together imparting long lasting detrimental features such as self similarity and long range dependency in to the traffic. The multimedia data fortunately is associated with redundancies that may be removed through efficient compression techniques. There exists a provision to control the compression or bitrates based on the availability of resources in the network. The traffic controller or shaper has to optimize the quality of the transferred multimedia data depending up on the state of the network. In this chapter, a novel traffic shaper is introduced considering the adverse properties of the network and counteract with the same.

Exploiting the Inter-Domain Hierarchy for the QoS Network Management

The Internet is an interconnection of multiple networks called domains. Inter-domain routing is ensured by BGP which preserves each domain’s independence and announces routes arbitrarily chosen by domains. BGP messages carry no information concerning quality parameters of announced routes. The authors’ goal is to provide domains with information regarding the congestion state of other domains without any changes in BGP. A domain, which is aware of heavily congested domains, can choose a bypass instead of a route exhibiting possible problems with QoS satisfaction. They propose a mechanism which sends alert messages in order to notify domains about the congestion state of other domains. The major difficulty consists in avoiding flooding the Internet with signaling messages. The authors’ solution limits the number of alerts by taking advantage of the hierarchical structure of the Internet set by P2C and P2P relationships. Their algorithm is distributed and heuristic because it is a solution to an NP-complete and inapproximable problem. They prove these properties by reducing the Steiner problem in directed acyclic graphs to our problem of alert diffusion. The simulations show that our mechanism significantly diminishes the number of unavailable domains and routes compared to those obtained with BGP routing and with a theoretical centralized mechanism.

Model Based Approach for QoS Constrained Communication and Data Integration among Multiple Agents

Meeting the agreed quality of service in a resource crunched data network is challenging. An intelligent element is required to carry out the activities involved. The inferences drawn with different rules need to be merged. Agents are useful for handling this responsibility in data networks and help in resource sharing. An agent is basically an entity that can be viewed as perceiving its environment through sensors and acting upon its environment through effectors. To handle the network traffic, the agents acquire the traffic status and provide the information on the availability of resources to the source of the traffic. Hence the study on agent communication has become important. Intelligent agents continuously perform the activities including perception of dynamic conditions in the environment, reasoning for interpretation of the perceptions, solve problems, draw inferences and determine actions.

An Analysis of Quality of Service Architectures

During the last years Internet evolution demanded for new and richer applications. To fulfill the novel and more complex application requirements, new solutions in many domains were required. One of these domains is the network support, assuring, into some extend, a specific or predictable treatment to traffic; therefore, in this chapter, we present a broad view of the main efforts available on the literature in order to provide Quality of Service (QoS) in both wired networks and wireless sensor networks (WSNs). For this purpose, the authors present: (1) the more relevant QoS architectures and technologies along with some of its recent improvements; (2) the different perspectives that combine some of those architectures and technologies into more complex solutions, in order to achieve stronger QoS and/or performance; (3) the most relevant QoS issues in WSNs environments; and (4) through the comparison of the several solutions, they list the advantages and limitations and reveal some relations among the existing QoS solutions.

QoS Signaling Security in Mobile Ad Hoc Networks

A quality of service (QoS) signaling system is necessary for QoS provision in a mobile ad hoc network (MANET). A QoS signaling system in MANETs is vulnerable to various types of attacks, ranging from fabrication and modification of messages to denial of services, which can cause failures of QoS provisions. Security is thus a critical issue for a signaling system. However, distinctive characteristics of MANETs make security mechanisms effective in conventional networks inapplicable in this environment. This chapter describes issues and challenges, and examines mechanisms specifically designed to provide security for QoS signaling systems in MANETs.

Disruption in the ICT-Sector

In this chapter, the authors discuss innovations associated with the transition from the circuit-switched public telephone network to IP packet-switched networks for the provision of voice services by focusing on research findings in the area of quality of service (QoS). To give a meaningful answer on how this transition affects the telecommunications industry, we elaborate on the frequently-cited concept of disruptive innovations, pioneered by Harvard Professor Clayton M. Christensen.

Multiple Optimization of Network Carrier and Traffic Flow Goals Using a Heuristic Routing Decision System

This chapter presents a multiple constraint optimization algorithm called routing decision system (RDS) that uses the concept of preference functions to address the problem of selecting paths in core networks that satisfy traffic-oriented QoS requirements while simultaneously satisfying network resource-oriented performance goals. The original contribution lies in the use of strong scales employed for constructing a multiple criteria preference function in an affine space. The use of preference functions makes it possible for paths that match both traffic-oriented and resource-oriented goals to be selected by the algorithm. The RDS algorithm is used in conjunction with a heuristic path finding algorithm called Constraint Path Heuristic (CP-H) algorithm which is a novel approach to finding a set of constraint paths between source and destination nodes in a network. The CP-H algorithm finds multiple paths for each metric and then passes all the paths to the RDS algorithm. Simulation results showed that the CP-H/RDS algorithm has a success rate of between 93 and 96% when used in Waxman graph topologies, and is shown to be significantly better than other heuristic based algorithms under strict constraints. In addition, it is shown that the associated execution time of the CP-H/RDS algorithm is slightly higher than other heuristic based algorithms but good enough for use in an online traffic engineering (TE) application. Simulations to assess the performance of CP-H/RDS algorithm in a TE environment show that the algorithms has lower call block rates than other TE algorithms. It is also shown that the CP-H/RDS has a 96% probability of providing at least two distinct feasible backup paths in addition to the main QoS path. A framework for implementing the CP-H/RDS as a routing server is proposed. The routing decision system server (RDSS) framework is novel in that the complexity introduced by QoS awareness remains outside the network.