Communication device, communication method, program, and communication system

A communication device comprising:

• a transmitting unit that transmits two or more pieces of protocol information, each of which indicates a protocol, to another communication device;
• a receiving unit that receives selected protocol information indicating a protocol that has been selected from two or more protocols indicated by the two or more pieces of protocol information on a basis of priority set for protocol selection from the other communication device;
• and
• a communication control unit that controls communication with the other communication device according to the protocol indicated by the selected protocol information received by the receiving unit.

A communication method comprising:

• receiving, by a communication device, two or more pieces of protocol information, each of which indicates a protocol, from another communication device;
• selecting, by a processor, a protocol on a basis of priority set for protocol selection from protocols common to two or more protocols usable by the communication device and two or more protocols indicated by the two or more pieces of protocol information;
• and
• controlling communication with the other communication device according to the selected protocol.

A communication method comprising:

• transmitting, by a communication device, two or more pieces of protocol information, each of which indicates a protocol, to another communication device;
• receiving selected protocol information indicating a protocol that has been selected from two or more protocols indicated by the two or more pieces of protocol information on a basis of priority set for protocol selection from the other communication device;
• and
• controlling, by a processor, communication with the other communication device according to the protocol indicated by the received selected protocol information.

A program that causes a computer to function as a communication device comprising:

• a receiving unit that receives two or more pieces of protocol information, each of which indicates a protocol, from another communication device;
• a selecting unit that selects a protocol on a basis of priority set for protocol selection from protocols common to two or more protocols usable by the communication device and two or more protocols indicated by the two or more pieces of protocol information;
• and
• a communication control unit that controls communication with the other communication device according to the protocol selected by the selecting unit.

A program that causes a computer to function as:

• a transmitting unit that transmits two or more pieces of protocol information, each of which indicates a protocol, to another communication device;
• a receiving unit that receives selected protocol information indicating a protocol that has been selected from two or more protocols indicated by the two or more pieces of protocol information on a basis of priority set for protocol selection from the other communication device;
• and
• a communication control unit that controls communication with the other communication device according to the protocol indicated by the selected protocol information received by the receiving unit.

A communication system comprising:

• a first communication device that transmits two or more pieces of protocol information, each of which indicates a protocol;
• and
• a second communication device,
• wherein the second communication device includes
• a receiving unit that receives the two or more pieces of protocol information from the first communication device,
• a selecting unit that selects a protocol on a basis of priority set for protocol selection from protocols common to two or more protocols usable by the first communication device and two or more protocols indicated by the two or more pieces of protocol information, and
• a communication control unit that controls communication with the first communication device according to the protocol selected by the selecting unit.