Abstract: The fairness of the band allocation is analyzed for each tiny stream in several aggregate streams in DiffServ system agreement, i.e., several typical control algorithms serving fairness (RED, WRR, FQ) are chiefly analyzed, including these algorithms’ ideas, realization methods, techniques and their own defects, and a new algorithm serving fairness is brought forward, based on combining the WRR algorithm with the FQ algorithm. The new algorithm better solves the problem of the fairness of each tiny stream in an aggregate stream when the network is congested. Its purpose is to realize the QoS guarantees in the IP wide area network, even the whole Internet. It gives some guidance for reasonably allocating the band resource in the network.

Key words: computer network, QoS, DiffServ agreement, fairness