The present invention provides a multi-service queuing method and
apparatus that provides exhaustive arbitration, load balancing, and
support for rapid port failover. Routers and switches according to the
present invention can instantaneously direct the flow of traffic to
another port should there be a failure on a link, efficiently handle
multicast traffic and provide multiple service classes. The fabric
interface interfaces the switch fabric with the ingress and egress
functions provided at a network node and provides virtual input and
output queuing with backpressure feedback, redundancy for high
availability applications, and packet segmentation and reassembly into
variable length cells. The user configures fixed and variable-length
cells. Virtual input and output queues are coupled to a switch fabric.
Statistics regarding the virtual input and output queues are collected
and packet queuing for the virtual input and output queues is controlled
using the collected statistic to provide congestion control for the
virtual input and output queues and the switch fabric.