Performance analysis of partially ordered and partially reliable transport services
Rahmi Marasli · 1997
The performance of a new class of transport layer services, called partially ordered/partially reliable, is investigated through analytic modeling and simulation. These services fill the gap between traditional ordered/reliable (e.g., TCP) and unordered/unreliable (e.g., UDP) transport services by allowing an application to specify controlled levels of loss and reordering. We show the performance improvements by using partially ordered/partially reliable services as compared to ordered/reliable service. We also analyze the effects various network and application parameters on the system performance. Results show that the use of ordered/reliable transport service when an application only needs a partially ordered/partially reliable service can cause considerable throughput drops, delay increases and buffer utilization increases in lossy networks. On the other hand, at high loss rates, unordered/unreliable service is unable to respect an application's loss and reordering tolerances. Thus, in lossy environments, partially ordered/partially reliable service is necessary to avoid the extra cost of ordered/reliable transport service, and, at the same time, to guarantee the minimal reordering and reliability that an application requires.