Impact of per-VC and single FIFO queuing on ABR congestion control

Queuing disciplines and their impact on congestion of Available Bit Rate (A BR) service in Asynchronous Transfer Mode (ATM) networks are investigated. In particular, two queuing disciplines, namely, First-In-First-Out (FIFO) a nd per-VC (virtual connection) queuing, are examined. Performance in terms of fairness, throughput, cell loss rate, buffer size and network utilizatio n are benchmarked via extensive simulations. Implementation complexity anal ysis and tradeoffs associated with each queuing implementation are addresse d. In contrary to the common belief, our investigation demonstrates that pe r-VC queuing which is costlier and more complex does not necessarily provid e any significant improvement over the simple FIFO queuing. These significa nt results will be of great interest and industrial value to the ATM Forum and vendors. Congestion control algorithms should be designed in such a way that they function well even in the presence of simple queuing disciplines .