DECnet is a network protocol suite developed by Digital Equipment Corporation (DEC) in the 1970s and 1980s. It was designed to allow communication between different computer systems and devices within a network, primarily used with DEC's VMS (Virtual Memory System) operating system.
DECnet operates at the transport layer of the OSI (Open Systems Interconnection) model and provides reliable, connection-oriented communication. It offers various services such as routing, name resolution, file transfer, remote terminal access, and distributed computing. The protocol suite includes layers such as network layer (NCL), transport layer (TP4), session layer (NSP), and data link control layer (LAN).
DECnet provides a hierarchical addressing scheme using the DECnet Area and Node Numbers, allowing for efficient routing within a network. It also supports routing between different networks using gateways, enabling communication between different DECnet systems.
One key feature of DECnet is its ability to support both synchronous and asynchronous communication modes, which enables efficient data transfer based on the characteristics of the network and the requirements of the application.
Although DECnet's usage has decreased over the years with the decline of DEC's systems, it has played a significant role in the development of networking technology. Many of the concepts and technologies introduced by DECnet have influenced the design of other network protocols and have contributed to the evolution of computer networking.
