This notification indicates that the G.Bond port's downstream data rate has reached/dropped below or exceeded the low downstream rate threshold, specified by gBondPortConfThreshLowDnRate. This notification MAY be sent for the -O subtype ports while the port is 'up', on the crossing event in both directions: from normal (rate is above the threshold) to low (rate equals the threshold or is below it) and from low to normal. This notification is not applicable to the -R subtypes. It is RECOMMENDED that a small debouncing period of 2.5 sec, between the detection of the condition and notification, be implemented to prevent simultaneous LinkUp/LinkDown and gBondLowDnRateCrossing notifications from being sent. The adaptive nature of the G.Bond technology allows the port to adapt itself to the changes in the copper environment; e.g., an impulse noise, alien crosstalk, or a micro-interruption may temporarily drop one or more BCEs in the aggregation group, causing a rate degradation of the aggregated G.Bond link. The dropped BCEs would then try to re-initialize, possibly at a lower rate than before, adjusting the rate to provide the required target SNR margin. Generation of this notification is controlled by the gBondPortConfLowRateCrossingEnable object. This object maps to the TR-159 notification nGroupLowDownRateCrossing.