在OpenFlow协议中，下列哪个消息类型不属于Asynchronous消息？

A.OFPT_PACKET_IN

B.OFPT_PORT_STATUS

C.OFPT_FLOW_REMOVED

D.OFPT_PORT_MOD

A.OFPT_HELLO

B.OFPT_SET_CONFIG

C.OFPT_PORT_STATUS

D.OFPT_FEATURES_REQUEST

A.OFPT_PACKET_IN

B.OFPT_PORT_STATUS

C.OFPT_FLOW_REMOVED

D.OPFT_FLOW_MOD

A.OFPT_FEATURES_REQUEST

B.OFPT_PACKET_OUT

C.OFPT_FLOW_REMOVED

D.OFPT_FLOW_MOD

A.OFPT_PACKET_OUT

B.OFPT_FLOW_MOD

C.OFPT_BARRIER_REQUEST

D.OFPT_FLOW_REMOVED

A.OFPT_PACKET_OUT

B.OFPT_FLOW_MOD

C.OFPT_BARRIER_REQUEST

D.OFPT_FLOW_REMOVED

A.OPFT_FEATURES_REQUEST

B.OFPT_PACKET_OUT

C.OFPT_FLOW_REMOVED

D.OFPT_FLOW_MOD

A.CONTROLLER

B.ALL

C.TABLE

D.IN_PORT

A.Packet-out消息可以用于指定某一个数据包的处理方法

B.控制器可以使用Packet-out消息，告诉交换机网络中如ARP、IGMP等数据包如何处理

C.Packet-out消息由OpenFlow控制器发出并发送到OpenFlow交换机

D.当用于链路发现时，控制器向一个交换机发送Packet-out消息，actions为从交换机的所有端口转发