An analytic study of partially ordered transport services

This paper presents an analytic model for investigating the throughput, delay and bu er utilization characteristics of partially ordered transport services. We analyze the e ects of packet and ack losses as well as applications' order requirements on overall system performance. The analytic model is veri ed by comparing its results against those of an OPNET simulation model. Analytic results show that for applications that can tolerate some reordering in the delivery of objects, use of partially ordered service instead of ordered service provides important bu er utilization and delay improvements, particularly as the loss rate increases and the order requirements of applications decrease. In terms of throughput, it makes no di erence which service (i.e., ordered, partially ordered, unordered) an application uses. Analytic study also shows that by judicious choice of sender's transmission order, overall system performance can further be improved in a partially ordered service.