IBM Network Control Program
The IBM Network Control Program (NCP)[1] ran on an IBM 3704, 3705 or 3745. It caused the machine to become a Systems Network Architecture Physical Unit Type 4 (PU4). A PU4 usually had SDLC links to remote cluster controllers (PU1/PU2) and optional SDLC links to other PU4s. Polling and addressing of the cluster controllers was performed by the NCP without mainframe intervention.
A local NCP connected to a System/370 channel via single address. A remote NCP had no direct connection to a mainframe. Instead a connection was made through a local NCP via SNA packet switching. NCP provided the link control and Network layer functions of a Wide area network. More information about NCP can be found in the article by W. S. Hobgood.
Further reading
- W. S. Hobgood (1976). "The role of the Network Control Program in Systems Network Architecture" (PDF). Vol 15, No 1. IBM Systems Journal. Retrieved 2006-08-26.
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Footnotes
- ^ Network Control Program is also the name of an ARPANET program, unrelated to this IBM program.