Rational: To count messages dropped because the queue present in ChannelOutboundQueue is full. This count will be helpful to mark the threshold downstream message processing capability of Openflow Java. Downsizing/upsizing resources surrounding this counter will decrease/increase downstream message processing capability.

A detailed discussion on it can be found at : https://lists.opendaylight.org/pipermail/openflowjava-dev/2016-May/000676.html