Then the media gateway analyzes the request contents ID and transmits the contents and metadata to the receiver using HTTP response message. When a part of contents is requested using range parameter, the response uses content-range parameter defined in entity-header of HTTP 1.1 standard. The status code of response header is '206 partial content' representing a part of contents. Specifically, the position and length is carried in content-range header and content-length header individually. Then the contents are carried in message-body. And when a part of contents is requested using HTTP GET method, the contents are carried in message-body of HTTP response message. In this case, the status code of HTTP response message header is '200 OK' and the content-range parameter is not used.