Specifications

3
Distributed Computing Support
The OpenVMS operating system supports distributed computing, including
the development and execution of distributed applications, with many built-in
services and many optional Digital products.
This chapter presents an introduction to the following topics:
• Distributed computing
• OpenVMS networking support for distributed computing
• OpenVMS client/server support, including that provided by PATHWORKS
and DECwindows Motif
• Distributed application support, including Digital DCE and ObjectBroker
For more information about these topics, see the OpenVMS Software Overview.
3.1 Distributed Computing
Distributed computing refers to the sharing of resources between two or more
processors. The processors can be located in one computer, or, as more often
the case, in separate computers. The resources to be shared include peripherals
such as disks and printers, data, applications, and software to manage remote
computers.
A distributed computing system that connects all parts of an enterprise can
function as though it were a single system. A user can have transparent access to
the integrated resources of the enterprise. A predominant design for distributed
computing is client/server computing, and a predominant form of client/server
computing is the use of larger computers as servers to personal computers (PCs).
3.2 OpenVMS Networking Support for Distributed Computing
OpenVMS networking support for distributed processing is provided by DECnet
software and hardware and by the DEC TCP/IP Services for OpenVMS product.
The DECnet family of communication products (software and hardware)
allows the OpenVMS operating system to participate in the DECnet network.
DECnet/OSI for OpenVMS VAX and DECnet/OSI for OpenVMS AXP are based
on the Open Systems Interconnection (OSI) model.
Users of DECnet/OSI for OpenVMS can choose between OSI networking protocols
and the Digital Network Architecture (DNA) networking protocols, which can run
simultaneously. OSI protocols permit communication with other vendors’ systems
that support OSI. The DNA protocols are the traditional networking protocols
that permit communication with other systems supporting compatible versions of
the DNA protocols.
3–1