System Communication Architecture

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System Communication Architecture

The System Communication Architecture (given as Systems Communication Architecture in some documents) is DEC's data networking architecture for VAXcluster systems; it defines the major constituent protocols, what functions each one performs, and how they interact. It allows the basic data-communication mechanism of a VAXcluster, the Computer Interconnect, to be shared between the numerous functions needed to operate the VAXcluster.

The System Communication Architecture has a three-tier model consisting of the layers (from top to bottom):

  • System Application (SYSAP), using the SYSAP Protocol
  • System Communications Services (SCS), using the SCS Protocol
  • Port/Port Driver Layer, using the PPD Protocol

SCA Services

The SCA architecture supports the performance of six different functions:

See the article linked below for detailed descriptions of the SCA functions.

External links

  • The System Communication Architecture, in DTJ, Vol. 1 No. 5, September, 1987 (pp. 24-30 of the PDF)