Evaluation of the ER Algorithm ERAQLES in Different ABR Environments
Résumé
ABR was standardised by the ATM Forum in 1996. Source, destination and switch behaviours were specified. However, a lot of freedom was left to the switch manufacturers to implement an efficient algorithm compliant with the ABR specifications. There exists three different behaviours. Namely, they are binary switches, Relative Rate (RR) switches and Explicit Rate (ER) switches.
In this paper, a new ER algorithm named ERAQLES is described. It is original because it uses the buffering capacities of the switches as well as a novel control function to derive an optimum explicit rate for the connections. The basic mechanisms of ERAQLES are presented and its performance is compared to ERICA and MACR solutions.
The ability of these algorithms to achieve fairness in some interesting situations is investigated. We first consider the case of networking environments where both RR and ER switches are involved. Second, we explore the efficiency of these solutions when facing VBR traffic competing with ABR. Results shows that due to its design properties, ERAQLES outperforms ERICA in most situations.