This value reports the Synchronous Bandwidth Allocation overhead for this PATH in bytes per frame, and is fixed at zero on stations that don't support synchronous service. An administrator uses it together with cntFddiPATHSba to understand the true bandwidth cost of synchronous traffic on this path, including per-frame overhead. For example, when calculating how much of the ring's total bandwidth synchronous service actually consumes on this path, the admin factors in this overhead value alongside the raw allocation.