+ - New field OXM_OF_METADATA, to align with OpenFlow 1.1.
+ - The OFPST_QUEUE request now reports an error if a specified port or
+ queue does not exist, or for requests for a specific queue on all
+ ports, if the specified queue does not exist on any port. (Previous
+ versions generally reported an empty set of results.)
+ - New "flow monitor" feature to allow controllers to be notified of
+ flow table changes as they happen.