This read-write yes/no setting enables fallback to 5.8 Kbps with double buffering, the more latency-tolerant variant of ifvceRate5k8x1. The extra buffering absorbs more jitter at this lower bit rate at the cost of added delay, which is a reasonable trade when link quality is poor as well as bandwidth-constrained. For example, an administrator dealing with both low bandwidth and packet jitter on a satellite backhaul might enable this object rather than the single-buffered 5.8 Kbps option.