As the Internet evolves towards the global multi-service network of the future, a key consideration is support for services with guaranteed Quality of Service (QoS). The proposed Differentiated Services (DiffServ) framework is seen as the key technology to achieve this. DiffServ currently concentrates on control/data plane mechanisms to support QoS but also recognises the need for management plane aspects through the Bandwidth Broker (BB). In this article we propose a model and architectural framework for supporting DiffServ-based end-to-end QoS in the Internet, assuming underlying MPLS-based explicit routed paths. The proposed integrated management and control architecture will allow providers to offer both quantitative and qualitative based services while optimising the use of underlying network resources.

Admission control is a key component for QoS delivery in IP networks because it determines the extent to which network resources are utilized and whether the contracted QoS characteristics are actually delivered. Unlike most of the existing approaches, we adopt a holistic view and position the admission control in a unified architecture, where traffic engineering and service management interact in different levels of abstraction and timescale. Distinguishing between service subscription and invocation epochs, the applied admission logic is based on a feedback model, the operation of which can be tuned by operational policies and business strategies. The validity of the approach is supported by a scalability analysis while it has also been verified by a prototype system.

Policy-based management can guide the behavior of a network or distributed system through high-level declarative directives that are dynamically introduced, checked for consistency, refined, and evaluated, resulting typically in a series of low-level actions. We actually view policies as a means of extending the functionality of management systems dynamically, in conjunction with preexisting hard-wired management logic. In this article we first discuss the policy management aspects of architecture for managing quality of service in IP DiffServ networks as presented in [1], and focus on the functionality of the dimensioning and resource management aspects. We then present an analysis of the policies that can influence the dimensioning behavior as well as the inconsistencies that may be caused by the introduction of such policies. Finally, we describe the design and implementation of the generic Policy Consumer component and present the current implementation status.

This article presents an architecture for supporting inter-domain QoS across the multi-provider global Internet. Whilst most research to date has focused on supporting QoS within a single administrative domain, mature solutions are not yet available for the provision of QoS across multiple domains administered by different organizations. The architecture described in this article encompasses the full set of functions required in the management (service and resource), control and data planes for the provision of end-to-end QoS-based IP connectivity services. We use the concept of QoS Classes and show how these can be cascaded using service level specifications (SLSs) agreed between BGP peer domains to construct a defined end-to-end QoS. We illustrate the architecture by describing a typical operational scenario.

Abstract