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

摘要

A network switch includes a buffer to store network packets and packet descriptors (PDs) used to link the packets into queues for output ports. The buffer and PDs are shared among the multiple traffic pools. The switch receives a multicast packet for queues in a given pool. The switch determines if there is unused buffer space available for packets in the given pool based on a pool dynamic threshold, if there is unused buffer space available for packets in each queue based on a queue dynamic threshold for the queue, if there are unused PDs available to the given pool based on a pool dynamic threshold for PDs, and if there are unused PDs available for each queue based on a queue dynamic threshold for PDs for the queue. The network switch admits the packet only into the queues for which all of the determining operations pass.

主权项

1. A method comprising:
at a network switch including a buffer having buffer space to store network packets, and a store of packet descriptors (PDs) that are used to link the network packets into queues that feed the packets to output ports of the switch, wherein the buffer space is shared among multiple traffic pools and the PDs are shared among the multiple traffic pools: receiving a multicast packet destined for multiple queues associated with a given pool; determining if there is unused buffer space available for packets in the given pool based on a pool dynamic threshold; determining, for each queue, if there is unused buffer space available for packets in that queue based on a queue dynamic threshold for that queue; determining if there are unused PDs available to the given pool based on a pool dynamic threshold for PDs; determining, for each queue, if there are unused PDs available for that queue based on a queue dynamic threshold for PDs for that queue; and admitting the packet only into the queues for which all of the determining operations pass.