Evaluating fairness in aggregated traffic marking

The need to offer different service levels on the Internet has encouraged the research in differentiated services (diffserv or DS) (K. Nichols et al., 1998; S. Blake et al., 1998). The article analyses the behavior and evaluates the performance of a fair traffic marker implementation, called Fair Marker (FM), as proposed by H. Kim (1999). The implementation exploits the duality between buffer allocation and token consumption in a token bucket marker in order to enforce fairness among different flows originated from the same subscriber network in a differentiated services (diffserv) domain. The results obtained show that fairness can be achieved when parameters are correctly set. We establish well-defined guidelines to help configure the FM parameters. The results also show that the FM cannot provide fairness in the allocation of excess bandwidth. In order to overcome this problem, we present an extension to the original proposal called Three-Color Fair Marker (TCFM). As an additional contribution, marking strategies proposals are discussed and classified.