QUANTA: Quality of Service Architecture for Native TCP/IP over ATM Networks

In this paper, we propose a Quality of Service (QoS) architecture, QUANTA, for an end system protocol suite. We use TCP(UDP)/IP over ATM as a testbed to develop the architecture. We measure the application-level QoS in terms of throughput, delay, round trip time, and loss to identify the base-line performance an application can expect from such an environment. From the no-load condition we measure the behavior of these protocols at various data rates and user submitted data block sizes. We demonstrate the trade-offs involved in obtaining high throughput, low delays, low round trip time, and zero losses at different data rates. We use host-load condition experiments to understand the interaction between the CPU-intensive jobs and the communication-intensive jobs. We use network-load condition experiments to observe interaction between multiple streams of the above two protocol-suites, and its effect on the application QoS. Given these observations we define the missing components in the current protocol architectures to provide tighter control on the QoS guarantees. Components we define in QUANTA include, a two-level application to network QoS translator, protocol tuning components, local feedback component, class-based scheduling etc.