This read-create enumerated value configures the ABR Trm parameter, the upper bound on the time between forward RM-cells for an active source, in milliseconds. An admin tunes this alongside the NRM cell-count parameter to ensure RM-cell feedback is generated regularly even during periods of light traffic, keeping the closed-loop rate control responsive. For example, if a source is sending data slowly enough that the NRM cell-count threshold rarely triggers, this time-based Trm bound ensures RM-cells are still sent periodically so congestion feedback doesn't stall.