ABR traffic sources adjust their rate as a function of feedback from the network. At regular intervals Resource Management cells (RM-cells) are inserted between regular data cells. ATM switches use an algorithm to modify the contents of the RM-cells depending on their level of congestion. The goal of these algorithms is to determine a fair rate allocation for each source without global knowledge of the network and without synchronization between the elements of the network.
We propose an innovative concept, called "virtual output queue", to support ABR traffic on an input-buffered, per Virtual Circuit (VC) queued switch. Standard algorithms have been adapted to operate on the proposed architecture. In order to evaluate and compare these algorithms, a simulator of the ATM testbed (iPOINT) at the University of Illinois has been enhanced with ABR functions.
Last updated 04/09/98 by Matthias Bossardt