This read-write value sets the buffer occupancy threshold that triggers ingress frame discard on this channel, active only when bbChanDiscardOption is set to frameDiscard. Once buffer usage crosses this threshold, the switch begins discarding entire incoming frames rather than individual cells, protecting buffer space during congestion. An admin tuning a data channel for early frame discard might lower bbChanFrmDiscardThreshold to shed complete frames sooner during buildup, rather than letting cells accumulate closer to full buffer exhaustion.