A hybrid end-to-end QOS architecture for heterogeneous networks (like the global information grid)

In this paper, we discuss an architecture and several mechanisms for meeting the quality of service (QoS) requirements of a set of very diverse applications over networks of very heterogeneous network domains. Many of these domains have significant mobility and temporal variation in resource capacities. While DoD 's global information grid (the GIG) is a prime example of a network of this type, commercial Internet and intranets increasingly face similar QoS requirements and operate in similar heterogeneous and dynamic environments. Meeting these challenges and still maintaining high resource efficiency, involves mechanisms in data, control, and management planes. In addition to meeting the QoS requirements of applications, these mechanisms also need to honor the importance level of the user and mission involved in the application. Thus, these mechanisms also perform policy based triage function when the requirements of all users and applications cannot be satisfied due to unexpectedly high demand or unexpected reduction in capacity due to failure, weather condition, etc. The architecture we propose here groups applications into service classes, each with its QoS requirements. Any specific instance of an application has an importance level (IL) determined by organizational policy. We use the requirements, one set for each service class-IL combination, as key drivers for designing a hybrid architecture involving session level admission control and preemption for session oriented service classes, and a packet level marking scheme allowing differential treatment of packets from different service classes and from different ILs.