Loss Differentiation Algorithms Vs Congestion Control Schemes: Dynamics and Performance

This paper carefully analyzes the behaviour of different congestion control schemes when used in combination with Loss Differentiation Algorithm. Three types of congestion schemes are discussed: delay-based, bandwidth estimation and AIMD, with one TCP variant representing each congestion scheme. We simulated two network scenarios with diverse link and traffic properties and evaluated the congestion schemes with integrated Loss Differentiation Algorithm in each of them. The integrated Loss Differentiation Algorithm is ideal, i.e. it makes no errors in its judgement. The behaviour of the schemes is analyzed from aspect of: the properties of the employed mathematical functions, the effect of presence or absence of additional network load (reverse and background traffic), and the achieved throughput. The results show very diverse scene and pinpoint the importance of the careful and delicate design of the congestion avoidance action when a non-congestion loss is detected.