An Internet network apparatus and a method of transferring data are provided. An encoder encodes source data and then generates communication unit input data. A communication unit sequentially transmits the communication unit input data to a client via, in order, an application layer, a transport layer, an IP layer, and a network connection layer. A transmission rate determination unit compares the communication unit input data with communication unit output data or a client input data, wherein the communication unit output data is transferred via at least the transport layer and is output from the communication unit, and the client input data is transferred to at least one client. A transmission rate controlling unit controls the encoder in response to a comparison result of the transmission rate determination unit. The transmission rate can be correctly determined so as to effectively transmit data to a plurality of clients.