This read-only PerfCounter64 counts frames of 256 to 511 octets received on this link aggregation group during the interval. It gives an administrator another data point in the frame-size distribution profile of the LAG's inbound traffic, useful for capacity and QoS planning that depends on typical packet sizes. For example, an engineer sizing buffer allocations for a shaper on this LAG would consult cmLagStatsESP256 alongside the other size buckets to understand the traffic's typical frame length.