Communication system and relay device, computer-readable recording medium storing relay program, as well as communication method and relay method

摘要

An intermediate relay device includes a corresponding information adder that adds, after receiving an outgoing message, an address assigned to the relay device to a list included in the outgoing message, and an outgoing message transmitter that specifies the address of a transmission destination and transmits the outgoing message to which the address has been added. The intermediate relay device further includes a return message transmitter that transmits, after receiving a return message, the return message based on a predetermined address corresponding to a device located at a prior stage to the intermediate relay device in a relay route for the outgoing message among addresses in the list included in the received return message.

主权项

1. A communication system comprising at least the following:
a transmitter/receiver that transmits an outgoing message including a list; a final-stage relay device which is a final destination for the outgoing message and which transmits a return message to the transmitter/receiver in response to the outgoing message; a first-stage relay device that relays the outgoing message and the return message; and at least one intermediate-stage relay device located between the first-stage relay device and the final-stage relay device; (1) the transmitter/receiver comprising:
a first message generator that generates a first outgoing message including a list to which an address assigned to the transmitter/receiver itself is added; anda first transmitter that transmits the first outgoing message generated by the first message generator to the final-stage relay device with designating the final-stage relay device as a final destination, (2) the first-stage relay device comprising:
a first receiver that receives the first outgoing message;a second message generator that adds, after the first receiver receives the first outgoing message, an address assigned to the first-stage relay device itself to the list of the received first outgoing message to generate a second outgoing message; anda second transmitter that transmits the second outgoing message generated by the second message generator to the final-stage relay device with designating the final-stage relay device as a final destination, and (3) the final-stage relay device comprising:
a second receiver that receives the second outgoing message;a third message generator that generates the return message to which the list included in the second outgoing message received by the second receiver is added; anda third transmitter that transmits the return message based on an address added to the list of the return message to the transmitter/receiver with designating the transmitter/receiver as a final destination, wherein:
(4)the first receiver of the first-stage relay device receives the return message, andthe second transmitter of the first-stage relay device transmits the return message based on a predetermined address which is included in the list of the return message received by the first receiver and which corresponds to the transmitter/receiver located at a prior stage to the first-stage relay device with reference to the transmitter/receiver in an outgoing route that is a relay route for the outgoing message, and(5)the intermediate-stage relay device comprising:
a third receiver that receives the second outgoing message;an address adder that adds an address of the intermediate-stage relay device itself to the list of the second outgoing message received by the third receiver; anda fourth transmitter that transmits the second outgoing message to which the address has been added by the address adder,the third receiver of the intermediate-stage relay device receives the return message,the fourth transmitter of the intermediate-stage relay device transmits the return message based on a predetermined address which is included in the list of the return message received by the third receiver and which corresponds to a device located at a prior stage to the intermediate-stage relay device with reference to the transmitter/receiver in the outgoing route, andthe first receiver of the first-stage relay device receives the return message from the intermediate-stage relay device located at a posterior stage to the first-stage relay device with reference to the transmitter/receiver in the outgoing route.