VNET
Encyclopedia
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 and 1990s. Through it, a number of protocols were developed to deliver e-mail amongst time sharing computers over alternate transmission systems.
VNET was first deployed as a private host to host network among CP/67 and VM/370 mainframes beginning before 1975. It was based on RSCS
, a virtual machine
based communications program. RSCS used synchronous data link protocols, not SNA/SDLC, to support file to file transfer among virtual machine users. The first several nodes included Scientific Centers and Poughkeepsie
, New York lab sites.
RSCS
compatible communications code was subsequently developed for MVT/HASP, MVT/ASP and MVS
mainframe operating system
s. By September 1979, the network had grown to include 285 mainframe nodes in Europe, Asia and North America. Unlike the Internet
, 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 1 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.
IBM
International Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...
, and provided the main email and file-transfer backbone for the company throughout the 1980s and 1990s. Through it, a number of protocols were developed to deliver e-mail amongst time sharing computers over alternate transmission systems.
VNET was first deployed as a private host to host network among CP/67 and VM/370 mainframes beginning before 1975. It was based on RSCS
RSCS
RSCS,the fundamental software that powered the world’s largest network prior to the Internet and which directly influenced both internet development and user acceptance of networking between independently managed organizations, was an acronym for the Remote Spooling Communications Subsystem...
, a virtual machine
Virtual machine
A virtual machine is a "completely isolated guest operating system installation within a normal host operating system". Modern virtual machines are implemented with either software emulation or hardware virtualization or both together.-VM Definitions:A virtual machine is a software...
based communications program. RSCS used synchronous data link protocols, not SNA/SDLC, to support file to file transfer among virtual machine users. The first several nodes included Scientific Centers and Poughkeepsie
Poughkeepsie (city), New York
Poughkeepsie is a city in the state of New York, United States, which serves as the county seat of Dutchess County. Poughkeepsie is located in the Hudson River Valley midway between New York City and Albany...
, New York lab sites.
RSCS
RSCS
RSCS,the fundamental software that powered the world’s largest network prior to the Internet and which directly influenced both internet development and user acceptance of networking between independently managed organizations, was an acronym for the Remote Spooling Communications Subsystem...
compatible communications code was subsequently developed for MVT/HASP, MVT/ASP and MVS
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...
mainframe operating system
Operating system
An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...
s. By September 1979, the network had grown to include 285 mainframe nodes in Europe, Asia and North America. Unlike the Internet
Internet
The Internet is a global system of interconnected computer networks that use the standard Internet protocol suite to serve billions of users worldwide...
, 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 1 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.