Administering acknowledgment messages (‘ACKs’) in the Transmission Control Protocol (“TCP”) that include establishing a TCP connection between a sender and a receiver, receiving by the receiver one or more TCP messages from the sender, and transmitting an ACK from the receiver to the sender only when necessary. Administering ACKs in TCP according to embodiments of the present invention may include measuring by the sender a round trip time for transmission of TCP messages between the sender and the receiver and transmitting to the receiver a data-bearing TCP message once per round trip time. Establishing a TCP connection between a sender and a receiver may include measuring by the receiver a round trip time for transmission of TCP messages between the receiver and the sender. Transmitting an ACK only when necessary may include transmitting an ACK when no message from the sender arrives at the receiver for two round trip times.