[Retracted] An Adaptive Authenticated Model for Big Data Stream SAVI in SDN-Based Data Center Networks

Table 2

Typical OFPT messages between the controller and switch.

OFPT message	Communication type	Message description
Hello	Controller to switch	The SDN controller sends its information as identity number to the access layer switch following the corresponding TCP handshake.
Hello	Switch to controller	Supported switch information is replied.
Features request	Controller to switch	The SDN controller requires for validating, which ports on the access layer switch are trusted and available.
Set config	Controller to switch	The SDN controller requires the access layer switch to send flow expired timestamp.
Features reply	Switch to controller	List of flow table match fields (ports, port speeds, supported tables, and actions) is replied by the access layer switches.
Port status	Switch to controller	Enables the access layer switch to inform that SDN controller of flow changes to port speeds or connectivity.