HP DECnet Phase IV for OpenVMS Alpha and OpenVMS I64, Version 8.3

HP DECnet for OpenVMS Alpha and OpenVMS I64, Version 8.3 SPD 48.48.11
task-to-task communication is offered by means of the
System Service interface that extends the capabilities
provided by the transparent mode. These capabilities
include support for interrupt messages and multiple in-
bound connect requests.
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 adja-
cent Phase IV or DECnet-Plus nodes, or on any two
nonadjacent Phase IV or DECnet-Plus nodes in the
same network connected by Phase IV or DECnet-Plus
routing nodes. DECnet for OpenVMS imposes no spe-
cial data formatting requirements on the user.
Network Resource Access
File Access — File access is supported to and from re-
mote 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 resid-
ing on a remote OpenVMS node. In addition to se-
quential access to a file, several other access meth-
ods are supported through RMS using DECnet for
OpenVMS. These methods include 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 ac-
counts on a specific remote system. One proxy account
should be designated as the default proxy account on
the remote system.
Command Language File Management
Most OpenVMS Digital Command Language (DCL)
commands can be used to perform network file op-
erations. These commands include: ANALYZE, AP-
PEND, BACKUP, CLOSE, CONVERT, COPY, CREATE,
DELETE, DIFFERENCES, DIRECTORY, DUMP, OPEN,
PRINT, PURGE, READ, SEARCH, SUBMIT, TYPE, and
WRITE. The operation of these commands is trans-
parent except for commands that invoke processing
on a specific system (that is, SUBMIT/REMOTE and
PRINT/REMOTE). Only a node name added to a file
specification is required to invoke the network capabili-
ties via one of these commands.
Using the COPY command, a user can transfer sequen-
tial, relative, and indexed-sequential (ISAM) files be-
tween DECnet nodes that support compatible file struc-
tures and record formats. Sequential or relative files
with fixed length, variable length, or variable length with
fixed control field records can be transferred between
two OpenVMS systems. Similarly, multikeyed indexed
files with variable or fixed length records are supported.
The SUBMIT/REMOTE command allows command files
residing on a remote node to be submitted for execution
at the remote node. The command file must be in the
format expected by the node responsible for execution.
DECnet for OpenVMS also allows OpenVMS command
files to be received from other systems and executed.
The DCL command EXCHANGE/NETWORK, allowing
for the transfer of files to or from heterogeneous sys-
tems, is available. This command gives users the op-
tion to transfer file types between MS-DOS®, ULTRIX
or Digital UNIX, and OpenVMS systems regardless of
record semantics. Unlike the COPY command, which
preserves file and record organization during a file trans-
fer, this command enables the user to modify file and
record attributes during file transfer.
Downline System Loading
DECnet for OpenVMS allows for the loading of an unat-
tended system using the services provided by the Main-
tenance Operations Module (MOM). MOM provides a
set of maintenance operations over various types of
circuits by using the Maintenance Operations Protocol
(MOP). A loadable system is a system that has a load
device enabled for MOP service functions and for which
a properly formatted load file is supplied. Downline load-
ing involves transferring a copy of the properly format-
ted load file image of a remote node’s operating system
from an OpenVMS node to the unattended target node.
For example, DECnet for OpenVMS permits the user to
load routing software from the OpenVMS node down-
line to the target node. Load requests can come from
the local DECnet for OpenVMS operator or from the tar-
get node. Downline loading is supported for HP server
products. However, this facility is not supported over
asynchronous lines.
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 checkpointed to the host OpenVMS file
system and later restored to main memory in the remote
node. These features simplify the operation of network
systems that do not have mass storage devices.
This facility is not supported over asynchronous lines.
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 man-
ager in fault isolation on a remote system. This facility
is also supported for HP server products.
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