HP 3000 Manuals HP 3000 Manuals
Appendix B Glossary
Introduction
This is a selected glossary of terms relating to SNA NRJE and SNA. These
are some comprehensive data processing dictionaries:
* Computer Dictionary, C. J. Sippl & R. J. Sippl; Howard W. Sams & Co,
Inc. ,1982
* Data Communications Dictionary, C. J. Sippl; Van Nostrand Reinhold,
1976
* Vocabulary for Data Processing, Telecommunications, and Office
Systems (IBM GC20-1699)
B
Batch communications: A form of data communications in which a
facility collects data over a period of time and then submits collected
information to a host computer. Typical batch communication consists of
large amounts of information transmitted at infrequent intervals.
BIND: An SNA command sent by the host to NRJE. This command specifies
the detailed protocol that NRJE accepts before initiating an LU-LU
session.
C
Chain: A sequence of RUs constituting a recoverable entity.
Communications controller: A front-end processor which provides an
interface between the communications facilities and a computer. IBM
provides programmable and non-programmable communications controllers.
An INP is a communications controller.
Console: A logical device through which commands are transmitted to
the host job entry system, and responses (messages generated by the host)
are received by NRJE.
D
Data set: In IBM terminology, any file.
DD: An IBM JCL command defining a data set.
F
FM header: An SNA Function Management header. These headers select
destinations or sources for subsequent data transmission and supply
information for other data management tasks.
Formid: A special form identifier for output data sets, which is used
as a key into a Lookup Table of file equations. A formid is a string of
eight characters or less. It is composed of alphanumeric characters, IBM
National characters (#, $, or @), or a period (.). A formid reference,
as in a SUBMIT command, must be delimited by single quote marks; for
example, 'formid'.
H
Half-session: In SNA, a component that provides FMD services, data
flow control, and transmission control for one of the sessions of a
network addressable unit (NAU).
Host: A host system is a central computer which provides services for
other computers and terminals attached to it.
I
INIT-SELF: An SNA request to the SSCP to initiate an LU-LU session.
Intrinsic: A subprogram provided by Hewlett-Packard systems. These
subprograms perform common functions such as opening files, opening
communications lines, or transmitting data over a communications line.
J
JCL: IBM job control language. JCL is used to tell the operating system
the names and locations of programs and the locations of data for those
programs.
JECL: IBM job entry control language. JECL statements are used for job
control under the VSE/POWER subsystem. These statements define a job to
VSE/POWER and specify how job input and output are to be processed.
JES2: A common IBM job entry subsystem used under the MVS operating
system.
JES3: A common IBM job entry subsystem used under the MVS operating
system.
Job: A file to be transmitted to a host computer, to be executed as a
job.
Job entry subsystem: An IBM subsystem which provides a gateway for the
execution of jobs in a batch environment; for example, JES2.
Job management: The ability to specify the final destination of output
data sets at the time a job is submitted to NRJE to be transmitted. For
NRJE, this capability is enabled by the PRINT, PUNCH, and FORMS options
of the SUBMIT command.
"Job Received" message: A message returned from the host system
acknowledging that a job submitted through NRJE is being received at the
host. For JES2 hosts it is the $HASP100 <169>ON READER<170> message.
For JES3 it is the IAT6101 message. VSE/POWER does not acknowledge job
reception to remote sites.
L
Ldev: A logical device; a disc file, a set of disc files, or a
physical device. An HP 3000 ldev is identified by a number or a device
class name.
Ldn: Logical device number. See ldev.
Logical device: See ldev.
Logical printer: A logical printer receives line printer images from a
host system.
Logical punch: A logical punch receives card punch images from a host
system.
Logical reader: A logical reader transmits card punch images to a host
system. (Also see
Virtual reader.)
Logical unit: See LU.
Logical writer A logical writer is a logical printer or a logical punch.
LU: An SNA logical unit. An LU is the SNA entity through which
application data is transmitted within an SNA network. An LU provides
access to an SNA network for an end user. It formats message units,
displays information, and handles error recovery. Multiple LUs can
reside in an SNA node.
LU class: A set of LUs on an HP 3000. NRJE/V will identify individual
LUs only if they have separate class names.
M
Mainframe: A mainframe is a computer that generally has a large amount
of memory and operates at a high speed.
N
NAU: Network addressable unit. The NAU represents the source and
destination of data in a network. A communications session must exist
before data can be transferred. Three types of NAUs exist: SSCPs, PUs,
and LUs. Sessions are established by the SSCP,
* First with the PU.
* Then, with each LU before two LUs can communicate in a session.
Four types of sessions exist:
SSCP-SSCP
SSCP-PU
SSCP-LU
LU-LU
NCP: Network control program. This program supports SNA communications
on the IBM 3705 communications controller.
NM: Node management. This is an MPE user capability required for NRJE
manager tasks.
NSPE: Network services procedure error. An SNA request from the SSCP to
the LU indicating an error during session startup or shutdown. On
receipt of this message, NRJE logs the content and terminates the LU
session.
O
OP: MPE system supervisor capability.
Operating system: An operating system is a master control program for
a computer.
Outfence: The priority value at which, or below which, jobs or line
printer output will be deferred. Also, the MPE console command which
sets the outfence.
Output management: The ability to route output by using special form
identifiers (formids) in the job JCL. The formids are used to key into a
Lookup Table that maps the formid to a file equation identifying the
final destination of the output.
P Physical unit: See PU.
Programmatic access: Programmatic access is a design feature of some
systems which allows you to use the system's features from programs you
write. SNA NRJE has both command access and programmatic access.
PU: A component of an SNA node. A PU controls the physical resources of
a node and reports errors and physical failures to the SSCP. One PU
resides in each node. A PU is the access method in a host node, the NCP
in the communications controller node, and the hardware and software in
peripheral nodes. These are the PU types for each kind of node:
* PU.T5, type 5, host node with SSCP
* PU.T4, type 4, communications controller node
* PU.T2, type 2, cluster controller node
* PU.T1, type 1, terminal node
A PU.T2 is emulated on the HP 3000 by the SNA link product.
R
Remote: A workstation that is not local to the host system, and is
configured under the host job entry subsystem. A remote can be connected
to its host by communications facilities or by direct attachment.
RH: Request or response header. These are attached to SNA RUs to
control data flow and support other network services.
RU: Request or response unit.
S
SDLC: Synchronous Data Link Control. SDLC is the data link level
communications protocol used in SNA.
SIGNAL: An SNA request primarily used to interrupt an LU, to send higher
priority data to that LU.
SNA: Systems Network Architecture, a comprehensive specification for
distributed data processing developed by IBM. SNA defines a layered
protocol for communicating and controlling a communications network
within the IBM environment.
SNA NRJE: HP's Systems Network Architecture Network Remote Job Entry.
This HP product emulates the RJE product on an IBM 8100 minicomputer
running the DPPX (Distributed Processing Programming Executive) Operating
System. This emulation enables users on the HP 3000 to submit batch
jobs, through an SNA network, to an IBM host or compatible mainframe for
processing. The host can then send the output back to the HP 3000 for
printing or storing on disk.
Spooled reader: The MPE ldev for holding jobs to be sent to the host
for a given NRJE workstation.
SSCP: System services control point. An SSCP manages nodes within its
domain. An SSCP stores status information for personnel to maintain a
network. It exists only in the host node and is implemented by the
communications access method.
T
TERM-SELF: An SNA request to the SSCP to terminate an LU-LU session.
TH: Transmission header. A transmission header is used by the
Transmission Control and Path Control layers for routing and sequencing
data sent through an SNA network.
Transmission queue: A queue of jobs to be transmitted to the host;
spooled reader.
V
Virtual reader: A logical device configured into the operating system
that is used to queue files waiting for transmission to the host on a
logical reader. (Also see Logical reader.).
VSE/POWER: A common IBM subsystem used to control the input and output
of jobs to the VSE operating system environment.
VTAM: Virtual Telecommunications Access Method. An IBM communications
access method which implements SNA on the host.
W
Workstation: An intelligent terminal, or a collection of input/output
devices managed by a computer or a control unit. An SNA NRJE workstation
is a collection of LUs communicating with a host job entry subsystem,
transmitting from a common spooled reader.