AuthorsB. F. Davik
TitleFairness Aspects of Buffer-Insertion Rings in General and Resilient Packet Rings in Particular
Publication TypePhD Thesis
Year of Publication2005
Date PublishedAugust
PublisherFaculty of Mathematics and Natural Sciences, University of Oslo
Thesis Typephd

The use of ring topologies in computer networks, was introduced in the late 1960s/early 1970s, with the Newhall ring being an example of an early implementation. Since then, many different solutions for ring networks have been proposed and implemented. One of the fundamental problems in such networks, in the presence of several users with high demands for bandwidth, is to simultaneously achieve high utilization, low delay and fair access to the ring's bandwidth resources. In this thesis, we cover issues related to the above problems in ring networks. However, we limit our focus to the above problems in the context of buffer-insertion rings and a particular type of buffer-insertion rings - namely the IEEE 802.17 Resilient Packet Ring. As such, our published results have a strong focus on Resilient Packet Rings. However the general findings from our experiments should be applicable to buffer-insertion (as well as slotted) rings. In our research contributions, we start by proving an introduction to the RPR standard and its problem area. This contribution provides a starting-point of study for the RPR novice, be it an network engineer or a university professor looking for an introduction to RPR technology. Then, we proceed by presenting an analytical model of the RPR aggressive fairness mode. By this model, a starting point is provided for a safer configuration of a Resilient Packet Ring, as well as reducing the number of heuristics needed. Next, we provide several contributions in which we analyze and propose improvements to various performance deficiencies in Resilient Packet Rings. Some of these deficiencies are commonly known in the RPR research community, while others are not so well known. And finally, at the end, we present an application of RPR, which is made possible by the workings of the fairness and service differentiation capabilities provided by the RPR standard.