This read-only Integer32 (0..2147483647) reports the Minimum Cell Rate for the ABR call in the backward direction, the guaranteed floor for return-direction throughput. An administrator uses this as the throughput guarantee for the call's return path, distinct from the forward-direction guarantee in cwspAbrCallFwdMcr. For example, an application whose return path carries acknowledgments needs a much smaller cwspAbrCallBwdMcr than a symmetric bidirectional transfer would require.