This read-only INTEGER reports the bandwidth used in the transmit direction for the Bursty Data A traffic class on the trunk. An administrator tracks this as one of two distinct bursty-data priority tiers on the platform, separate from the Bursty Data B class, when assessing how trunk capacity is divided among data traffic priorities. For example, if Bdata A traffic, typically the higher of the two tiers, is consuming most of the trunk's spare capacity, lower-priority Bdata B connections may be starved during peak periods.