This read-only INTEGER reports the Maximum Number of Cells a source may send for each forward RM-cell in the backward direction for the ABR call, with a default of nrm32(5). An administrator uses this to understand how frequently RM-cell feedback is generated relative to data cells on the return path of this specific call. For example, a smaller backward NRM value produces more frequent rate-management feedback on the call's return-direction traffic than the default nrm32(5).