According to Request for Comment 1594 (RFC 1594), a datagram is “a self-contained, independent entity of data carrying sufficient information to be routed from the source to the destination computer without reliance on earlier exchanges between this source and destination computer and the transporting network.” In other words, a datagram is a self-sufficient message unit that contains all the information necessary to reach its destination.

Related Terms

The term datagram has generally been replaced by the term packet. Datagrams or packets are the message units that the Internet Protocol (IP) works with and that the Internet transports.

Characteristics of Datagrams

A datagram or packet must be self-sufficient, meaning it must not depend on previous exchanges, as there is no fixed-duration connection between the two communication points, as occurs, for example, in most voice telephone conversations. This type of protocol is called connectionless.

Importance of the Connectionless Protocol

In the context of computer networks, the connectionless characteristic of datagrams is crucial. Since there is no stable and permanent connection between the sender and the receiver, each datagram must contain all the information necessary for its delivery. This approach allows for greater flexibility and resilience in communication, as packets can follow different paths through the network and do not depend on a single stable connection.

Applications

Datagrams are used in many network protocols, including IP (Internet Protocol), which is the foundation of the Internet. IP breaks data down into small packets (datagrams) that are sent individually across the network and reassembled at the destination point. This methodology is essential for the efficient and robust operation of modern communication networks.

Conclusion

In summary, the datagram represents a fundamental element in modern network communications, characterized by its independence and self-sufficiency. The transition from the term datagram to packet reflects the evolution of technical language, but the basic concept remains a key component of the Internet network structure.