Connectionless protocol is a standard that enables the transmission of data from one computer to another, even though no effort is made to determine whether the receiving computer is online or capable of receiving the information. This is the underlying protocol in any packet-switching network, such as the Internet, in which a unit of data is broken down into small-sized packets, each with a header containing the address of the data’s intended destination. On the Internet, it is called the Internet Protocol (IP).
IP is concerned only with breaking down the data into packets for transmission and reassembling the packets after they have been received. A connection-oriented protocol (on the Internet, TCP) works at another level to ensure that all the packets are received. Research on computer networks has disclosed that this design is highly efficient. See connection-oriented protocol, TCP