Communication system, control apparatus, communication apparatus, information-relaying method, and program

A first control apparatus connected to a network including a communication apparatus that forwards a packet according to control information set by a control apparatus, said first control apparatus comprising:

• a control unit controlling said communication apparatus by setting said control information in said communication apparatus;
• and
• an information transmission unit transmitting information necessary for interoperation with a second control apparatus to said second control apparatus that operates in concert therewith via said communication apparatus,
• wherein said information necessary for interoperation between said first control apparatus and said second control apparatus includes information for performing synchronization between said first control apparatus and said second control apparatus,
• wherein said communication apparatus is connected to each of said first control apparatus and said second control apparatus with a logical control channel such that the logical control channel for different control apparatuses is provided, and
• wherein said control information is transmitted to said communication apparatus as a smaller size message than said information necessary for interoperation between said first control apparatus and said second control apparatus.

A second control apparatus connected to a network, the second control apparatus including:

• a communication apparatus that forwards a packet according to control information set by a control apparatus;
• and
• a first control apparatus that controls said communication apparatus by setting said control information in said communication apparatus, said second control apparatus comprising:
• a control unit controlling said communication apparatus by setting said control information in said communication apparatus;
• and
• an information receiving unit receiving information necessary for interoperation with said first control apparatus from said first control apparatus via said communication apparatus, and operating in concert with said first control apparatus,
• wherein said information necessary for interoperation between said first control apparatus and said second control apparatus includes information for performing synchronization between said first control apparatus and said second control apparatus,
• wherein said communication apparatus is connected to each of said first control apparatus and said second control apparatus with a logical control channel such that the logical control channel for different control apparatuses is provided, and
• wherein said control information is transmitted to said communication apparatus as a smaller size message than said information necessary for interoperation between said first control apparatus and said second control apparatus.

A communication apparatus, comprising:

• a first unit receiving information necessary for interoperation between a plurality of control apparatuses from a control apparatus out of said plurality of control apparatuses that control said communication apparatus by setting control information in said communication apparatus;
• and
• a second unit transmitting information necessary for interoperation between said plurality of control apparatuses to the remaining control apparatuses of said plurality of control apparatuses,
• said communication apparatus forwarding a packet according to the control information set by the control apparatus,
• wherein said information necessary for interoperation between a first control apparatus and a second control apparatus of said plurality of control apparatuses includes information for performing synchronization between said first control apparatus and said second control apparatus,
• wherein said communication apparatus is connected to each of said first control apparatus and said second control apparatus with a logical control channel such that the logical control channel for different control apparatuses is provided, and
• wherein said control information is transmitted to said communication apparatus as a smaller size message than said information necessary for interoperation between said first control apparatus and said second control apparatus.

An information-relaying method in a network including:

• a communication apparatus that forwards a packet according to control information set by a control apparatus;
• a first control apparatus that controls said communication apparatus by setting said control information in said communication apparatus;
• and
• a second control apparatus that operates in concert with said first control apparatus, said information-relaying method including:
• causing said communication apparatus to receive information necessary for interoperation between said first and second control apparatuses from said first control apparatus;
• and
• causing said communication apparatus to forward said information necessary for interoperation between said first and second control apparatuses to said second control apparatus,
• wherein said information necessary for interoperation between said first control apparatus and said second control apparatus includes information for performing synchronization between said first control apparatus and said second control apparatus,
• wherein said communication apparatus is connected to each of said first control apparatus and said second control apparatus with a logical control channel such that the logical control channel for different control apparatuses is provided, and
• wherein said control information is transmitted to said communication apparatus as a smaller size message than said information necessary for interoperation between said first control apparatus and said second control apparatus.