Abstract

In this paper, the concept of fairness in computer networks is investigated. We motivate the need of examining fairness issues by providing example future application scenarios where fairness support is needed in order to experience sufficient service quality. Fairness definitions from political science and their application to computer networks are described and a state-of-the-art overview of research activities in fairness, from issues such a queue management and tcp-friendliness to issues like fairness in layered multi-rate multicast scenarios, is given. We contribute with this paper to the ongoing research activities by defining the fairness challenge with the purpose of helping direct future investigations to with spots on the map of research in fairness. Document type: Part of book or chapter of book

Abstract

Several new protocols such as RBUDP, User-Level UDP, Tsunami, and SABUL, have been proposed as alternatives to TCP for high-speed data transfer. The purpose of this paper is to analyze experimentally the effects of SABUL congeston control algorithm on SABUL and performance metrics such as bandwidth utilization, self-fairness, and aggressiveness. Our results confirm some expected behavior of SABUL and reveal some less expected one. Our experiments also indicate that SABUL implementation and design can result in an even more erratic behavior and degraded performance under high-congestion conditions. Document type: Part of book or chapter of book

Abstract

In an IP network, if the source rates are increased beyond the service rates of the routers, then queues of packets waiting to be routed at the buffers, build up and exceed the buffering capacity of these routers leading to packets getting dropped. This results in low throughput and congestion collapse. In such networks, an AQM mechanism manages queue lengths in buffers and enables the end-systems to react to such losses by reducing their packet rate, avoiding severe congestion. Random Early Detection (RED) is one of the first AQM mechanisms to be used to avoid congestion in this manner. In this paper, the existing Normal and Gentle RED algorithms of Floyd as well as the justification for the proposed modified exponential RED algorithm have been discussed along with the results obtained on the functioning of the algorithms. Functioning of the algorithm proposed has also been tested using ns2 Simulator.