This field reports the number of bytes received per second on this PM instance, exposed here as cienaCesPmBasicTxRxHistoryBinRxBytesPerSec. On this Ciena CES port's PM data, this is a pre-computed rate gauge for the bin rather than a running total, letting you read this port's received-bandwidth directly without manually differencing two RxBytes polls and dividing by elapsed time yourself; and this lives in the basic bandwidth-profile-aware PM group's history bin — a closed-out interval whose own Duration and State tell you how long it ran and whether it closed cleanly, so the number is settled rather than still being written to. For example, polling this field mid-bin and seeing 106,000,000 bytes/sec received tells you this port's live throughput right now, no extra math required.