VNET is an international computer networking system deployed in the mid-1970s and still in current, but highly diminished use. It was developed inside IBM and provided the main

email Electronic mail (email or e-mail) is a method of exchanging messages ("mail") between people using electronic devices. Email was thus conceived as the electronic ( digital) version of, or counterpart to, mail, at a time when "mail" meant ...

and file-transfer backbone for the company throughout the 1980s and 1990s. Through it, a number of protocols were developed to deliver email amongst time sharing computers over alternative transmission systems. VNET was first deployed as a private host to host network among CP/67 and

VM/370 VM (often: VM/CMS) is a family of IBM virtual machine operating systems used on IBM mainframes System/370, System/390, zSeries, System z and compatible systems, including the Hercules (emulator), Hercules emulator for personal computers. The ...

mainframes beginning before 1975. It was based on RSCS, a

virtual machine In computing, a virtual machine (VM) is the virtualization/emulation of a computer system. Virtual machines are based on computer architectures and provide functionality of a physical computer. Their implementations may involve specialized hardw ...

–based communications program and an inter machine protocol developed in IBM's Advanced Systems Development Division's Remote Service System (RSS) prototype which produced some of the technology in the IBM Tivoli product. RSCS used the

Binary Synchronous Communications Binary Synchronous Communication (BSC or Bisync) is an IBM character-oriented, half-duplex link protocol, announced in 1967 after the introduction of System/360. It replaced the synchronous transmit-receive (STR) protocol used with second gene ...

(BSC) protocol, not SNA/SDLC, to support file to file transfer among virtual machine users. The first several nodes included Scientific Centers and

Poughkeepsie, New York Poughkeepsie ( ), officially the City of Poughkeepsie, separate from the Town of Poughkeepsie around it) is a city in the U.S. state of New York. It is the county seat of Dutchess County, with a 2020 census population of 31,577. Poughkeepsi ...

lab sites. RSCS-compatible communications code was subsequently developed for MVT/HASP, MVT/ASP and

MVS Multiple Virtual Storage, more commonly called MVS, was the most commonly used operating system on the System/370 and System/390 IBM mainframe computers. IBM developed MVS, along with OS/VS1 and SVS, as a successor to OS/360. It is unrelated ...

mainframe

operating system An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs. Time-sharing operating systems schedule tasks for efficient use of the system and may also in ...

s. By September 1979, the network had grown to include 285 mainframe nodes in Europe, Asia, and North America. Unlike the

Internet The Internet (or internet) is the global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices. It is a '' network of networks'' that consists of private, pub ...

, VNET switched files among mainframes using a store and forward technique. Many of the early connections operated over dial-up phone lines at speeds of 1200 to 2400 bits per second. The addition of a 19.2 kbit/s trans-Atlantic satellite circuit in late 1977 was considered a major step forward. End users typically sent files between 100 and 100,000 bytes in length. The user could expect delivery within one minute to several hours. File delivery was acknowledged on a hop by hop basis but there was no end to end delivery confirmation. However, by the late 1970s an email application was developed that provided delivery confirmation as well as message archiving. What began as a research activity among engineers and scientists became, by 1980, a valuable business asset for many organizations within IBM. The first widely disruptive

computer worm A computer worm is a standalone malware computer program that replicates itself in order to spread to other computers. It often uses a computer network to spread itself, relying on security failures on the target computer to access it. It wil ...

, " Christmas Tree EXEC" in December 1987, originated on BITNET and spread to this network.

External links

Interview with VNET creator Edson Hendricks

Vnet VNET is an international computer networking system deployed in the mid-1970s and still in current, but highly diminished use. It was developed inside IBM and provided the main email and file-transfer backbone for the company throughout the 1980s an ...

Wide area networks VM (operating system) {{compu-network-stub

See also

External links