Missing end-system QoS components: A case-study

In this paper, we propose a Quality of Service (QoS) architecture for an end-system protocol-suite. We use TCP/IP using ATM as the networking paradigm, as a testbed to propose our QoS architecture. With the help of no-load condition, host-load condition, and network-load condition experiments, we identify the QoS perturbations caused in such an environment. We analyze these results behind the QoS perturbations, and use them to arrive at the missing components in the current protocol architecture. We use TCP/IP/AAL5/ATM, and AAL5/ATM as two performance comparing protocol suites to obtain knowledge on the missing QoS components. 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-o s involved in obtaining high throughput, low delays, low Round Trip Time, and zero losses at di erent 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 e ect on the application QoS.