The value of tmnxMcPathBdlDefChlBwFallDelay specifies the value the
bandwidth manager uses the falling-delay threshold to hold on to the
previous highest bandwidth until the delay time has expired while
operating in dynamic bandwidth mode. This allows the bandwidth manager
to ignore momentary drops in channel bandwidth. This value can only be
set if tmnxMcPathBdlDefChlBwActivity is not set to 'none'.