This Counter64 is the number of packets received on this endpoint just since the previous poll. It matters on the live receive-side counter set UCS Manager keeps for one Ethernet endpoint (a blade's vNIC adapter port, an I/O Module uplink, or a fabric-interconnect server port) inside a UCS domain because a rate calculated from this delta (packets per second) is the figure most monitoring tools alert on for a packet-rate storm, as opposed to a byte-rate storm. A totalPacketsDelta of 1,200,000 over a one-minute poll on this interface is roughly 20,000 packets per second, well above what normal server traffic would generate and worth investigating as a possible broadcast storm.