Keywords: Internet, Inter-domain, Quality of Service, Traffic Engineering, Service Level Specification

Project rationale

In today’s Internet, there are numerous relationships between a multitude of stakeholders who are each responsible for part of the provision of end-to-end connectivity and value-added services. Service and content providers rely on connectivity services provided by what could be termed a loose federation of organisations, which together provide end-to-end connectivity across the global Internet. No single organisation is responsible for vertical integration, in terms of applications over service providers over network connectivity, or horizontal integration, in terms of global geographical coverage.

Figure 1: Many autonomous systems are involved in end-to-end service provision

A major limitation of the Internet is its lack of service level guarantees due to its basic design for best-effort packet delivery. The introduction of the IP Differentiated Services framework and subsequent research and standardisation efforts, represent significant progress on solving the problem of QoS delivery in a single domain for unicast traffic. However, inter-domain communication and information access is the rule rather than the exception, and extensive deployment of QoS-based services will not take place unless they can be offered across domains. The provision of end-to-end QoS is a wide-open research issue whose solution will transform the Internet to the global multi-service network of the future.

MESCAL views two major aspects as essential to the deployment and delivery of inter-domain QoS-based IP services: the definition of QoS-based connectivity services to be provided by stakeholders; and second, the means to engineer network resources to meet agreed performance and capacity targets for the contracted services. Together, these two dimensions aim at providing the means for a dynamically configurable Internet, with service requirements driving traffic engineering to meet end-to-end service demands.

Figure 2: Inter-domain interactions at service and resource layers

Figure 3: Building inter-domain QoS classes from intra-domain capabilities