If the Disconnect Request is determined to be of appropriate format and matching session(s) are present and terminated appropriately, then a Disconnect-Ack is sent in response. If all the attributes in the packet are not understood within this context or do not result in a matching DA controller and session, then the DA controller sends a Disconnect-NAK in response. If the DA controller is unable to appropriately terminate the matching session(s) for some reason, a Disconnect-NAK is sent in response.