In recent years, overlay networks have emerged as an attractive alternative for supporting value-added services. Many of these overlays are end-to-end overlays, but due to the difficulty of supporting end-to-end QoS purely in end-user overlays, backbone overlays for QoS support have been proposed. In this paper, we describe a backbone QoS overlay network architecture for scalable, efficient and practical QoS support. In this architecture, we advocate the notion of QoS overlay network (referred to as QSON) as the backbone service domain. The design of QSON relies on well-defined business relationships between the QSON provider, network service providers and end users. The QSON provider provisions its overlay network according to end user requests, purchases bandwidth from the network service providers based on their service level agreements, and sells its QoS services to end users via service contracts. A key challenge in making QSON a reality consists of efficiently determining routes for end user QoS flows based on the service level agreements with the underlying network service providers. Existing QoS routing techniques may not be applicable in QSON, since they are primarily designed for routing flows that reside wholly within a domain, while a QoS flow in a QSON will routinely straddle multiple domains. Thus, in this paper, we propose and present a scalable and distributed QoS routing scheme that can be used to efficiently route end user QoS flows through QSON. We use simulations to evaluate the scalability of the proposed routing scheme. We also discuss how to implement it in an incremental fashion. We implement a prototype protocol in PlanetLab, and by real experiments, we demonstrate the effectiveness of our solution.
Lao et al. proposed a distributed QoS routing protocol for backbone overlay networks referred to as QSON REF .
Distributed QoS Routing for Backbone Overlay Networks
Networking
Computer Science