Methods and apparatus for maintaining a queue

Typically, queues in a router device are used to track data information such as packets or data flows for later transmission to another downstream communication device. To reduce overhead associated with tracking an average queue length of a queue, a metric reflecting average queue length (or estimated queue length) is updated based on the occurrence of an event such as when the contents of the queue are modified. More specifically, if data is added or deleted from the queue, the metric reflecting an average fullness of the queue over time is updated at substantially the same time as updating the instantaneous queue length metric associated with the queue. This technique of synchronously updating both IQL and AQL simplifies the overall task of maintaining queue length information.