Communication device, communication system, control method for these, and program for causing computer to execute this method

A control method of a communication device, the control method comprising:

• a message processing procedure in which a message processing section, in a case where a connection has been established with a server which distributes display information to be displayed on a display device in synchronization with reproduction of content, processes a message from the server for controlling the distribution in accordance with a first protocol;
• a connection confirmation procedure in which a connection confirmation section confirms whether or not the connection has been established in accordance with a second protocol;
• and
• a connection request procedure in which a connection request section, in a case where the connection has not been established, requests establishment of the connection to the server in accordance with the second protocol.

A program for causing a computer to function as:

• a message processing procedure in which a message processing section, in a case where a connection has been established with a server which distributes display information to be displayed on a display device in synchronization with reproduction of content, processes a message from the server for controlling the distribution in accordance with a first protocol;
• a connection confirmation procedure in which a connection confirmation section confirms whether or not the connection has been established in accordance with a second protocol;
• and
• a connection request procedure in which a connection request section, in a case where the connection has not been established, requests establishment of the connection to the server in accordance with the second protocol.