DECnet-Plus

DECnet is the collective name for the family of communications products (software and hardware) that allow Digital-developed operating systems to participate in a network.

VSI DECnet for OpenVMS on Alpha, Integrity, and x86 allows a suitably configured OpenVMS system to participate as an end node. With proper network planning, DECnet networks can contain up to 1,023 nodes per network area and up to 63 areas per network.

DECnet for OpenVMS offers task-to-task communications, file management, down-line system and task loading, network command terminals, and network resource sharing capabilities using the Digital Network Architecture (DNA) protocols. DECnet for OpenVMS communicates with adjacent and non-adjacent Phase IV and DECnet-Plus nodes.

The network functions available to a DECnet for OpenVMS user depend, in part, on the configuration of the rest of the network. Each DECnet product offers its own subset of Digital Network Architecture (DNA) functions and its own set of features to the user.

Features

DECnet for OpenVMS offers the following features:

Task-to-Task Communication. Using DECnet for OpenVMS, an OpenVMS program can exchange messages with other user programs. The two user programs can be on the same node, on adjacent Phase IV or DECnet-Plus nodes, or on any two non-adjacent Phase IV or DECnet-Plus nodes in the same network connected by Phase IV or DECnet-Plus routing nodes. DECnet for OpenVMS imposes no special data formatting requirements on the user.
Network Resource Access:
- File Access — File access is supported to and from remote DECnet systems using RMS. User programs can sequentially read, create, and delete files on a remote node.
- Record Access — User programs can perform record level operations, such as GET, PUT, UPDATE, DELETE, FIND, and REWIND, to access and modify files residing on a remote OpenVMS node. In addition to sequential access to a file, DECnet allows for random access by relative record number, random access by key value, random access by Record File Address (RFA), and block I/O access by virtual block number.
Proxy Access. Remote users can have access to up to 15 proxy accounts on a specific remote system.
Command Language File Management. Most OpenVMS Digital Command Language (DCL) commands can be used to perform network file operations: ANALYZE, APPEND, BACKUP, CLOSE, CONVERT, COPY, CREATE, DELETE, DIFFERENCES, DIRECTORY, DUMP, OPEN, PRINT, PURGE, READ, SEARCH, SUBMIT, TYPE, and WRITE. The DCL command EXCHANGE/NETWORK, allowing for the transfer of files to or from heterogeneous systems, is available.
Downline System Loading. DECnet for OpenVMS allows for the loading of an unattended system using the services provided by the Maintenance Operations Module (MOM). MOM provides a set of maintenance operations over various types of circuits by using the Maintenance Operations Protocol (MOP).
Downline Task Loading. Initial task images for loadable systems can be stored on OpenVMS file system devices and loaded into remote nodes. Programs already executing on loadable remote systems can be check-pointed to the host OpenVMS file system and later restored to main memory in the remote node.
Upline Dumping. Memory images of adjacent nodes connected by DECnet can be written or dumped into a file on an OpenVMS system. This facility helps the system manager in fault isolation on a remote system.
Network Command Terminal. The DCL command SET HOST allows a terminal user on one DECnet node to establish a logical connection to another DECnet node that uses the Command Terminal Protocol (CTERM). This connection makes the terminal appear physically connected to the remote system, and the operator can use all the standard system and network utilities supported by that remote node.
OpenVMS MAIL Utility. The DECnet for OpenVMS software allows users to send and receive OpenVMS mail to or from users of other systems that operate within the same DECnet network.
OpenVMS PHONE Utility. DECnet increases the scope of OpenVMS PHONE to allow active users on different systems in the same network to exchange information.
Cluster Alias. DECnet supports the ability to access some or all nodes in a VMScluster using a separate alias node address, while retaining the ability to address each node in the cluster individually.
Network Management. The Network Control Program (NCP) performs three primary functions: displaying statistical and error information, controlling network components, and testing network operation. These functions can be performed locally or executed at remote Phase IV nodes that support these functions. NCP allows for planning, building, tuning, and controlling DECnet networks.
LAN Failover. DECnet for OpenVMS provides support for OpenVMS LAN failover sets. A LAN failover set is defined by the system manager and consists of a set of like adapters (all the same class) that support LAN failover.