csDs3Ds1CurrentBESs is a read-only PerfCurrentCount counter reporting the number of Bursty Errored Seconds — a one-second period with 2 to 319 CRC errors, too many for a clean second but not enough to be Severely Errored — that this channelized DS1 (T1) circuit carried inside the DS3 has recorded in the current 15-minute measurement interval, i.e. right now. A rising count here is the operational signal that sporadic, non-catastrophic noise on the DS1 is happening on that interface, which is exactly the kind of degradation a monitoring admin wants an early warning of before it causes an outage. For example, an admin polling csDs3Ds1CurrentBESs on this channelized DS1 (T1) circuit carried inside the DS3 every few seconds and watching the count jump upward in real time would immediately suspect sporadic, non-catastrophic noise on the DS1, and could start a bit-error-rate test before the fault gets worse.