Abstract: Techniques for performing user-configurable traffic management functions on streams of packets. The functions include multicasting, discard, scheduling, including shaping, and segmentation and reassembly. In the techniques, the functions are not performed directly on the packets of the stream, but instead on descriptors that represent stored packets. Output of descriptors from all traffic queues, including discard traffic queues, is scheduled. Scheduling is done using a hierarchy of schedulers. The form of the hierarchy and the scheduling algorithms used by the schedulers in the hierarchy are both user configurable. As disclosed, the techniques are implemented in a traffic management coprocessor integrated circuit. The traffic manager coprocessor is used with a digital communications processor integrated circuit that performs switching functions. The buffers for the packets are in the digital communications processor.

Abstract: Techniques for performing user-configurable traffic management functions on streams of packets. The functions include multicasting, discard, scheduling, including shaping, and segmentation and reassembly. In the techniques, the functions are not performed directly on the packets of the stream, but instead on descriptors that represent stored packets. A packet's descriptor includes at least an identifier for the packet and a specifier for a set of traffic management functions to be performed on the descriptor. The user configures a set of traffic management functions for a traffic queue of descriptors. The specifier in the descriptor specifies a set of traffic management functions by specifying a descriptor queue. In multicasting, a descriptor is copied and placed on more than one traffic queue; with regard to discard, when the discard function associated with a traffic queue determines that a packet is to be discarded, the descriptor is placed in a discard traffic queue.

Abstract: In an ATM network, the physical resources are shared by many connection and the bandwidth is allocated virtually to each connection. The connection admission control (CAC) algorithm uses traffic descriptors, desired quality of service (QOS) parameters etc., to compute a required bandwidth for a requested connection by which it makes a decision to admit or reject the connection. For admission control for a requested VBR connection, two required bandwidths are calculated in two different ways, both of which take into consideration impacts of CBR traffic which is being serviced. The admission decision is based on the lesser of the two bandwidths.

Abstract: In an ATM network, the physical resources are shared by many connection and the bandwidth is allocated virtually to each connection. The connection admission control (CAC) algorithm uses traffic descriptors, desired quality of service (QOS) parameters etc., to compute a required bandwidth for a requested connection by which it makes a decision to admit or reject the connection. Unlike any prior CAC, the CAC of the invention for constant bit rate (CBR) service takes also into consideration the cells delay variation (CDV) for calculating the required bandwidth.