A transfer device comprising: means for recording or playing video or sound; a first network connection control section operable to control connection to a first network enabling transfer of content data and/or control data using a first address assigned by a device in the network which is operable to assign addresses for use in the first network; a second network connection control section operable to control connection to a second network enabling transfer of content data and/or control data using a second address assigned by a device having a routing function; an address table operable to store a correspondence between the first address of devices on the first network connected via the first network connection control section and the second address of the devices on the second network connected via the second network connection control section, wherein: the first network is connected through a transfer line according to a High-Definition Multimedia Interface standard; and the second network is a network using an Internet Protocol address as the second address and enabling data transfer with the outside, wherein the first network connection control section is capable of transferring a first command via the first network to another device on the network, the first command being for activating a communication function section for performing communication with the second network. means for recording or playing video or sound; a first network connection control section operable to control connection to a first network enabling transfer of content data and/or control data using a first address assigned by a device in the network which is operable to assign addresses for use in the first network; a second network connection control section operable to control connection to a second network enabling transfer of content data and/or control data using a second address assigned by a device having a routing function; an address table operable to store a correspondence between the first address of devices on the first network connected via the first network connection control section and the second address of the devices on the second network connected via the second network connection control section, wherein: the first network is connected through a transfer line according to a High-Definition Multimedia Interface standard; and the second network is a network using an Internet Protocol address as the second address and enabling data transfer with the outside, wherein the first network connection control section is capable of transferring a first command via the first network to another device on the network, the first command being for activating a communication function section for performing communication with the second network. the first network is connected through a transfer line according to a High-Definition Multimedia Interface standard; and the second network is a network using an Internet Protocol address as the second address and enabling data transfer with the outside, wherein the first network connection control section is capable of transferring a first command via the first network to another device on the network, the first command being for activating a communication function section for performing communication with the second network.