A memory management technique for maintaining packet order in a packet processing system

摘要

A memory management technique for maintaining packet order in a packet processing system involves maintaining a START indicator and a VALID indicator for each memory block in a packet memory. Packets are written in a number of successive memory blocks (718), and the START indicator corresponding to the first memory block of the number of successive memory blocks is set to indicate that the packet is available for processing. The packets are processed by a packet processor (716). When the packet processor (716) completes the processing of a particular packet, the VALID indicator corresponding to the first memory block associated with that packet is set to indicate that the packet is ready to be forwarded. The packet may become ready to be forwarded out of order. However, the packets are forwarded in first-in-first-out order by processing the packets in first-in-first-out order and only forwarding a particular packet if the VALID indicator corresponding to the first memory block associated with that packet is set to indicate that the packet is ready to be forwarded. Thus, a packet is not forwarded unless and until all previous packets have been forwarded, even if the packet is ready to be forwarded before one or more previous packets. <IMAGE>