Abstract: Scheduler methods and apparatus utilize a weight limited FIFO (WLF) method to provide weighted per-connection queuing while maximizing preservation of cell arrival order, thus minimizing additional cell delay variation (CDV) added during scheduling. The invention minimizes additional CDV of a connection until the connection exceeds its fair share of resource utilization.

Abstract: In an ATM communication system, a source transmitting in accordance with an Available Bit Rate service category must be policed to ensure that the cells are transmitted at a rate within the cell rate specified by the network at any given time. The usage parameter control system can only store a limited number of pending cell transmission rates to be enforced, and must make approximations by discarding certain stored pending cell transmission rates in order to make room for new cell transmission rates. This invention is directed towards a method for selecting which stored cell rates to discard that allows less cheating room in the cell rate enforcement than does the prior art, and that does not over-police.

Abstract: The invention provides a duplex processor arrangement wherein the processors are only pseudo-synchronized to each other. Each processor is provided with its own independent clock circuit and the two clock circuits operate at the same nominal frequency. A circuit means is provided for periodically forcing a rendezvous between processors whereat a controller circuit ensures that the processors have processed the same information since the last rendezvous. Each processor comprises a match circuit including memory means connected to store address/data information related to instructions performed by the processors. Each match circuit compares the information from the processors and generates an alarm signal upon a mismatch.