In a communication control equipment for transmitting data in an external predetermined memory to a network, there are provided a buffer memory unit for temporarily holding the data transferred thereto, a data transfer unit for performing a data transfer between the predetermined memory and the buffer memory unit, a unit for executing a protocol processing with regard to data held in the buffer memory unit, a control unit for controlling a transmission of the data processed by the protocol processing to the network, and a unit for producing a transmission start instruction at a start time instant within a range defined from a time instant when 1-packet data transfer from the predetermined memory to the buffer memory unit is commenced until a time instant when this data transfer is completed. The transmission start instruction is produced under a condition that the lower a data transfer speed from the predetermined memory to the buffer memory unit is relative to a transmission speed of the network, the later the start time instant is. A unit is also provided for causing the control unit to commence the transmission of the data processed by the protocol processing to the network at a later time instant during the time instant when the transmission start instruction is produced and the time instant when the protocol processing is terminated.