| 摘要 |
A packet forwarding node for a computer network comprises at least one receiving module and at least one output module including package list means (21) for maintaining a list of packets to be transmitted therefrom. The time for which a packet remains in the node is determined by grouping the packets into groups or "buckets" which are created at regular intervals, each bucket containing packets arriving within the same time interval, and keeping track of the age of each bucket. A bucket counter (33) counts the total number of buckets in existence, so indicating the age of the oldest packet. This counter is incremented by 1 at regular intervals and decremented by 1 each time the oldest bucket is emptied (or found to be empty). A bucket list shift register (30) has its contents shifted at each change of time interval, its bottom stage accumulates the number of packets arriving in a time interval, and an overflow accumulator (31) accumulates counts shifted out of its top end. The bucket list shift register may comprise a plurality of sections each of which is shifted at an exact submultiple of the rate of shifting of the previous section, the bottom stage of each section accumulating counts shifted out of the previous section. In an alternative embodiment, bucket boundary markers are inserted into the packet list means at each change of time interval. <IMAGE> |
