COMMUNICATION METHOD AND RELAY DEVICE

PROBLEM TO BE SOLVED: To improve the convenience of a user by making it easy to input data, such as text data and binary data, to a communication device capable of voice communication and data communication.SOLUTION: In a communication method performed by a relay device 2 connected to a communication device 1 via a network and also connected to a telephone set 3 and a data input terminal 4, the relay device 2 performs: a call control step for establishing a call of a voice communication session between the relay device 2 and the communication device 1 on the basis of a call request of the telephone set 3; a data communication establishment step for establishing a data communication session associated with the call of the voice communication session between the relay device 2 and the communication device 1 when receiving a connection request to the communication device 1 from the data input terminal 4; and a data communication step for transmitting data input from the data input terminal 4 by use of the HTTP protocol to the communication device 1 via the data communication session.