This read-only value is the incoming-direction counterpart to lportOutVAvailbwQoS3, reporting available inbound bandwidth remaining in the port's QoS Class 3 reservation. An admin checks this when the concern is inbound business-data load specifically, such as a port that primarily receives transactional data from a remote site rather than sending it. For example, a headquarters-side port aggregating inbound class-3 traffic from many branch offices would have its true remaining capacity for accepting yet another branch's traffic reflected in lportInVAvailbwQoS3, not the outgoing equivalent.