  An explicit rate switch scheme monitors the load at each link and gives
feedback to the sources. We define the overload factor as the ratio of the
input rate to the available capacity. In this paper, we present four overload
based ABR switch schemes which provide MCR guarantees. The switch schemes
proposed use the overload factor and other quantities to calculate feedback
rates. A dynamic queue control mechanism is used to achieve efficient usage of
the link, control queues and, achieve constant queuing delay at steady state.
The proposed algorithms are studied and compared using several configurations.
The configurations were chosen to test the performance of the algorithms in
presence of link bottlenecks, source bottlenecks and transient sources. A
comparison of the proposed algorithms based on the simulation results is
presented.
