Numerical Key Results for Studying the Performance of TCP Traffic under Class-Based Weighted Fair Queuing System

This paper presents a fluid model to estimate the performances of TCP traffics under a two CBWFQ (class-based weighted fair queuing) with variable rate. The system is then equivalent to two virtual links with variable capacities. At first, we give some results to evaluate the performance of TCP traffics under "Best Effort" architecture, then we try to exploit these results to provide key results to qualify performances characteristics of TCP traffic under CBWFQ system. The core of our analysis is based on some numerical observations and relies on the conservation of the average total number of flows carried by the system. Detailed packet level simulations of TCP flows show the accuracy of our analysis. The results presented in this paper allow a rapid performance evaluation of TCP traffic circulating in the actual IP networks.