This is the reverse-direction counterpart to cktAbrNRM, reporting how many cells pass between RM-cell insertions in the reverse direction of this ABR SVC. Because the reverse path's RM-cell frequency can be tuned independently, an admin can give the direction carrying more congestion-sensitive traffic tighter (more frequent) feedback without imposing that overhead on the other direction. A network engineer would compare cktRAbrNRM to cktAbrNRM to verify both directions get feedback often enough for the specific application's sensitivity to rate fluctuation.