Each Cisco Nexus 5500 platform interface is supplied with a dedicated pool of 640 KB distributed by the QoS subsystem among eight CoSs (called system classes in the QoS command-line interface [CLI]).


The buffering strategy on the UPC includes ingress and egress buffers from the pool of 640 KB of memory. Ingress buffering constitutes the majority of the buffering needs, and therefore most buffers are assigned to the ingress side; egress buffering is used mainly to sustain flow control for both Ethernet and Fibre Channel and to create an egress pipeline to increase throughput.

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