One embodiment provides a communication apparatus including: a first storage which stores connection information and an address; a connection information reading portion which reads connection information from the first storage upon reception of a packet transmission start instruction; a header generating portion which generates a header of a packet from the read connection information; a second storage which stores data at the address; and a data reading portion which reads data corresponding to the read connection information from the second storage, wherein the connection information reading portion is constituted by a first hardware, wherein the header generating and data reading portions are constituted by a second hardware, and wherein, while the data reading portion is reading data of a first packet or while the header generating portion is generating a header of the first packet, the connection information reading portion reads connection information of a second packet.