This is the largest single unicast-packet delta sample UCS Manager observed among the sub-intervals making up the current reporting period. 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 it captures a real application burst (e.g. a backup job or vMotion-style transfer) that the averaged figure would hide. A unicastPacketsDeltaMax spike to 60,000 on this interface coinciding with a nightly backup window is expected; the same spike at 3 a.m. on a Sunday with no scheduled job would not be.