Fair Queueing in ATM Networks: A Simulation Study

The issue of traffic control in ATM networks is of the utmost importance in the light of the heterogeneity of the traffic they carry. Each class of users is to be guaranteed a quality of service nominally different from what the other classes get. In other words, scheduling mechanisms are to be devised so as to minimize interference among traffic flows having different quality of service requirements. Fair Queueing (FQ -- also known as Packet-by-packet Generalized Processor Sharing) is recognised as one of the most promising scheduling mechanisms for ATM networks: its goal is to fairly provide connections with a bandwidth proportional to the share of link capacity they are entitled to. In doing this, FQ tries to emulate bit-per-bit round-robin scheduling, while weighing the amount of bandwidth for each connection so as to obtain different service classes. This technique was studied in a simple network scenario using CLASS, a software package for the simulation of ATM networks. Numerica..