This sets the maximum percentage of bandwidth that this QoS profile's queue is permitted to consume, capping it even if more bandwidth is otherwise available on the link. An admin uses this to prevent one traffic class from monopolizing a link even during periods when other queues are idle, the ceiling counterpart to the floor set by atiQosProfileMinBw. For example, capping a bulk-backup traffic profile at 30% MaxBw ensures that backup jobs can never crowd out other traffic entirely, even late at night when the link would otherwise be nearly empty.