Dynamic Protection Of Shared Memory Used By Output Queues In A Network Device

摘要

A network switch includes a buffer to store network packets linked to queues to feed the packets to output ports of the switch associated with the queues. The buffer is shared dynamically among multiple traffic pools. The network switch determines per-pool dynamic thresholds each based on an amount of unused buffer space, and per-queue dynamic thresholds based on amounts of unused buffer space available in the pools with which the queues are associated. The network switch receives packets, and for each received packet, the network switch admits the packet to the pool with which the packet is associated and the queue for which the packet is destined if (i) occupancy of the associated pool is less than the corresponding per-pool dynamic threshold, and (ii) occupancy of the queue for which the packet is destined is less than the corresponding per-queue dynamic threshold, and otherwise drops the packet.

主权项

1. A method comprising:
at a network switch including a buffer having buffer space to store network packets linked to queues to feed the packets to output ports of the switch associated with the queues, the buffer space being shared dynamically among multiple traffic pools: determining per-pool dynamic thresholds defining upper limits for per-pool occupancy each based on an amount of unused buffer space; determining per-queue dynamic thresholds defining upper limits for per-queue occupancy based on amounts of unused buffer space available in the pools with which the queues are associated; and receiving packets, and for each received packet:
admitting the packet to the pool with which the packet is associated and the queue for which the packet is destined if (i) occupancy of the associated pool is less than the corresponding per-pool dynamic threshold, and (ii) occupancy of the queue for which the packet is destined is less than the corresponding per-queue dynamic threshold; and for each receive packet; and
dropping the packet if both conditions (i) and (ii) are not met.