|
|
A B C D
E F G H
I J K L
M N O P
Q R S T
U V W X
Y Z
- access port
A special interface card in the system cabinet through
which the system console is connected.
- address
A numerical identifier defined and used by a particular protocol
and associated software to distinguish one node from
another.
- address key
See X.25 address
key.
- address resolution
In NS networks, the mapping of node names to IP addresses and the
mapping of IP addresses to link level addresses.
- address resolution protocol (ARP)
A protocol used by LAN links with Ethernet enabled that provides
a means of exchanging addressing information between Ethernet
nodes.
- adjacent
A node on a point-to-point network that is connected to another
node by a single link with no intervening nodes.
- ARP
See address resolution protocol.
- ASCII
American National Standard Code for Information Interchange. A
character set using 7-bit code used for information interchange among
data processing and data communications systems. The American
implementation of International Alphabet No. 5.
- asynchronous
A device's mode of operation in which a sequence of operations
are executed irrespective of time coincidence with any event. Devices
that are directly accessible by people (for example, terminal keyboards)
operate in this manner.
- Attachment Unit Interface
AUI. The cable that runs between each node (host, DTC, or other
device) and the Medium Attachment Unit (MAU) that connects it to the LAN
in a ThickLAN configuration.
- AUI
See Attachment Unit Interface.
- autodial
A dial link in which the remote node's telephone number is
automatically dialed by a modem or other device with this
capability.
- back-to-back configuration
A DTC configuration whereby MPE users connected to one DTC can
communicate with a non-MPE/iX system connected to another DTC via the LAN.
See also local
switching.
- backbone LAN
A thick LAN cable conforming to the IEEE 802.3 Type 10 BASE 5
Standard.
- backup configuration file
A file that contains a copy of the information contained in the
configuration file. The backup file, called NMCBACK.group.account
by default, is updated each time the configuration file is successfully
validated.
- banner
A welcome message displayed on your screen. On the local OpenView
workstation a banner appears when a remote connection is established with
the OpenView DTC Manager. A banner also can appear when you log on to
MPE.
- baud
The measure of the speed at which information travels between
devices, most commonly used in reference to terminal speed settings. Baud
represents signal events per second. When one bit represents each signal
change, baud is the same as "bits per second."
- binary mode
A data-transfer scheme in which no special character processing
is performed. All characters are considered to be data and are passed
through with no control actions being taken.
- bit
Binary digit. A unit of information that designates one of two
possible states, which are represented by either 1 or 0.
- block mode
A terminal processing mode in which groups, or "blocks," of data
are transmitted all at once.
- BNC T-Connector
A connector used to connect a computer or a component such as a
DTC to the LAN in a ThinLAN configuration.
- boundary
See network
boundary.
- bps
Bits per second. The number of bits passing a point per
second.
- broadcast
Communication method of sending a message to all devices on a
link simultaneously.
- byte
A sequence of eight consecutive bits operated on as a
unit.
- call
In X.25, a call is an attempt to set up communication between two
DTEs using a virtual circuit. Also known as a virtual call.
- call collision
A conflict that occurs at a DTE/DCE interface when there is a
simultaneous attempt by the DTE and DCE to set up a call using the same
logical channel identifier.
- called address
When a node sends out a call request packet, the packet contains
the address of the destination node. The address of the destination node
is the called address.
- calling address
When a node receives an incoming call packet, the packet contains
the address of the sending node. The address of the sending node is the
calling address.
- carrier
A continuous wave that is modulated by an information-bearing
signal.
- catenet
See
internetwork.
- CCITT
Consultative Committee for International Telephony and Telegraphy.
An international organization of communication carriers, especially
government telephone monopolies, responsible for developing
telecommunication standards by making recommendations. The emphasis is on
"recommendations"; no carrier is required to adhere to a CCITT
recommendation, although most do so in their own interests.
- CIB
The channel input/output bus in the backplane of an HP
e3000.
- circuit-switching network
A type of data communications network wherein a physical and
exclusive link is maintained between two communicating devices for the
call duration. An all-digital, circuit-switching network is often
referred to as an X.21 network.
- closed user group
An X.25 user facility that allows communication to and from a
pre-specified group of users and no one else.
- compatibility mode
A processing mode on HP e3000 computers that allows applications
written for MPE V/E-based systems to be ported and run without changes
or recompilation.
- computer network
A group of computer systems connected in such a way that they can
exchange information and share resources.
- configuration
1) The way in which computer equipment is physically
interconnected and set up to operate as a system.
2) The layout of the computer system, including the MPE table, memory,
and buffer sizes, that tells which peripheral devices are (or can be)
connected to the computer and how they can be accessed.
3) The process of defining the characteristics of a network in software.
For MPE/iX-based computers, the operating systems are configured through
use of the SYSGEN utility. Next, the Datacommunications and Terminal
Subsystem (DTS) link is configured by using NMMGR (running on the host)
and can, in addition, be configured using the OpenView DTC Manager
software (running on the OpenView Windows Workstation) depending on the
type of network management you use. A system that is to run network
services (NS 3000/iX) is configured through use of NMMGR. Access to X.25
is configured in two parts. The X.25 MPE/iX System Access software is
configured on the host through use of NMMGR. The DTC/X.25 Network Access
software residing on the DTC is configured at the OpenView Windows
Workstation through use of the OpenView DTC Manager.
- configuration file
The configuration file contains the information that the network
needs in order to operate. This file also contains information necessary
for link- level and NetIPC logging. The only file name that the system
recognizes is NMCONFIG.PUB.SYS
- control-X echo
Three exclamation marks (!!!) output to the terminal
screen when the cancel character (normally [CTRL]-X) is
entered.
- control-Y trap
A user-written procedure to which control is passed when the
subsystem break character (normally [CTRL]-Y) is entered during
execution of a program with subsystem break enabled.
- cross-validate
The process of assuring that information contained in two
locations is consistent where it is imperative that it be consistent. For
example, an automatic cross-validation occurs when you enter SYSGEN to
assure that information contained in NMCONFIG.PUB.SYS agrees
with system configuration data.
- CSMA/CD
Carrier Sense Multiple Access with Collision Detect, transmission
access method used by the LAN standard.
- CSN
See circuit-switching
network.
- CTB
The cache transfer bus in the backplane of an HP
e3000.
- CUG
See closed user
group.
- D bit
Delivery confirmation bit. Used in the X.25 protocol, the setting
of the D bit in DATA packets indicates whether delivery acknowledgment of
the packet is required from the local DCE or from the remote DTE. It
therefore allows the choice between local and end-to-end
acknowledgment.
- data
Basic elements of information that can be processed
or produced by a computer.
- data overrun
Transmitted data that is sent faster than the receiving equipment
can receive it. The resultant overflow data is lost. See also
flow control.
- Datacommunications and Terminal Controller
See DTC.
- Datapac
The national public PSN of Canada.
- Datex-P
The national public PSN of West Germany.
- DCE
Data circuit-terminating equipment. The interfacing equipment
required in order to interface to data terminal equipment (DTE) and its
transmission circuit. Synonyms: data communications equipment, dataset.
A modem is an example of a DCE.
- DDX
The national public PSN of Japan.
- dedicated printer
A printer that can be used only by one host on the LAN —
the one specified in the Destination Node Name in that printer's
configuration screen.
- default gateway
A gateway accessible by a system may be designated as a default
gateway. The network will then send any transmitted messages for which it
is unable to locate a destination through normal means to the default
gateway in a final effort to determine a transmission
route.
- demodulation
The process by which the information-bearing signal is retrieved
from a modulated carrier wave. The inverse of modulation.
- destination node name
In DTS configuration, it is either 1) the name of a host that a
user can be connected to by default (if switching is not enabled for that
user, or if automatic modem connection is enabled), or 2) the name of the
only host that can access a dedicated printer.
- device class
A collection of devices that have some user-defined relation.
Device classes are assigned through use of the NMMGR configuration
program.
- device driver
A software module that controls a specific type
of input/output device.
- device independence
A characteristic of the operating system that allows users to
selectively redirect input/output from a program, session, or job without
regard to the nature of the device.
- device name
See PAD
name.
- device-dependent characteristic
A file specification for which modifications are restricted
because of the type of device on which the file is opened. For example,
data directed to terminals must have a blocking factor of
one.
- devicefile
A file being input to or output from any peripheral device except
a disk. MPE/iX allows operations to be performed on the device itself as
if it were a file.
- Dial ID protocol
A proprietary Hewlett- Packard protocol that provides security
checking and address exchange for dial links.
- dial link
A connection made through public telephone lines.
- direct connection
A leased line, private line, or other non-switched
link in a network.
- direct dial
A dial link through which only one remote node can
be reached.
- direct-connect device
An asynchronous device that is connected directly to a DTC
through an RS-232-C or RS-422 cable, with no intervening communications
equipment. Also referred to as a "local connection."
- direct-path branching
The process of directly accessing any screen in NMMGR by entering
a path name in the Command: field. The path name must be
preceded by an at sign (@).
- domain name
A name designated for a system in ARPANET standard format. This
name can be used by other nodes on the network to access the host for
which it is configured.
- download
The process of loading operating code and configuration files
into the DTC's memory. The DTC is downloaded by the MPE/iX host for LANs
using host-based network management, and by the PC for DTCs managed by
the OpenView DTC Manager.
- driver
Software that controls input/output devices including
NS 3000/iX links.
- DTC
Datacommunications and Terminal Controller. The DTC is a hardware
device, configured as a node on a LAN, that enables asynchronous devices
to access HP e3000 computers. Terminals can either be directly connected
to the DTC, or they can be remotely connected through a Packet Assembler
Disassembler (PAD). The DTC can be configured with DTC/X.25 Network
Access cards and DTC/X.25 Network Access software. A DTC/X.25 iX Network
Link consists of two software modules: the X.25 iX System Access software
(running on the host) and the DTC/X.25 Network Access software (running
on the DTC).
- DTC identifier
An identifier used only within NMMGR to define the branch of the
configuration file containing information about a particular DTC. The
identifier must begin with a letter and can be up to eight characters
long.
- DTC Manager
See OpenView DTC
Manager.
- DTC node name
A unique name used to identify a DTC on a LAN. The node name
format is nodename.domain.organization, with each of the three
parts having up to 16 characters. The name begins with either a letter
or a digit.
- DTC station address (802.3 address)
A 12-digit hexadecimal number used to identify the DTC as a node
belonging to the network configuration. Also called the LAN address or
node address.
- DTC switching
A facility enabling terminal users to select any host system that
they want to connect to. DTC switching is available only when the
OpenView DTC Manager is used for network management.
- DTC/X.25 iX Network Link
Software and hardware that provides MPE/iX access to
private and public X.25 networks. The X.25 iX System Access software
resides on an HP e3000 host and is configured through use of NMMGR.
The DTC/X.25 Network Access software resides on the Datacommunications
and Terminal Controller and is configured at the OpenView Windows
Workstation for PC-based management and through NMMGR for host-based
management.
- DTC/X.25 Network Access
The X.25 software that resides on the Datacommunications
and Terminal Controller (DTC). To configure access to an X.25 network,
you must configure two software components: the X.25 iX System Access
(residing on the HP e3000 host), and the DTC/X.25 Network
Access. DTC/X.25 Network Access is configured through use of the
OpenView DTC Manager software for systems using PC-based network
management or throughNMMGR for systems using host-based network
management.
- DTC/X.25 Network Access card
The hardware card and channel adapter that provides X.25 Network
Access. It resides in the Datacommunications and Terminal Controller
(DTC).
- DTCCNTRL
A command file you can use to manage DTS configurations. Using
DTCCNTRL, you can dynamically implement DTS changes, automatically add a
new DTC, shutdown/restart DTS, and manage/dynamically configure
host-based X.25 connections.
- DTE
Data Terminal Equipment. Equipment that converts user information
into data-transmission signals or reconverts received data signals into
user information. Data terminal equipment operates in conjunction with
data circuit-terminating equipment.
- DTS
Datacommunications and Terminal Subsystem. This
consists of all of the Datacommunications and Terminal Controllers
(DTCs) on a LAN, their LANIC cards (attached to the host), the LAN
cable, and the host and DTC software that controls all related DTS
hardware.
- DTS restart
The startup of the DTS subsystem using the DTCCNTRL command
file after DTS has been shut down.
- DTS shutdown
The shutdown of the DTS subsystem, including the
release of all TIO-related resources, using the DTCCNTRL command
file.
- duplex
A transmission method that allows two-way communication.
If both ends of the transmission link can transmit simultaneously,
it is called full duplex. If only one end can transmit at a time,
it is half-duplex transmission.
- dynamic configuration
The ability to make DTS configuration changes using NMMGR
without rebooting the HP e3000 system.
- entry priority
In a point-to-point network, it is a ranking that
identifies the most desirable route for data to travel from a given
local node to a remote node.
- environment
A session that is established on a remote node.
- escape from data transfer character
A character that allows a user who is connected to a host system
through the DTC, to break that connection and return to the DTC switching
user interface. The default is [CTRL]-K. This character is used
only on networks managed by the OpenView
Windows Workstation.
- escape sequence
A sequence of characters beginning with the escape character and
followed by one or more other characters, used to convey control
directives to printers, plotters, or terminals.
- Ethernet
A Local Area Network system that uses baseband transmission
at 10 Mbps over coaxial cable and unshielded twisted pair. Ethernet
is a trademark of Xerox Corporation.
- event log
One of three circular files stored on the OpenView
windows workstation. It contains lists of events that are reported
by the DTCs for which it is responsible.
- extended packet sequence numbering
One of the optional Network Subscribed Facilities that provides
packet sequence numbering using modulo 128. If not subscribed,
modulo 8 is used.
- facility
An optional service offered by a packet switching
network's administration and requested by the user either at the time
of subscription for network access or at the time a call is made.
Also known as user facility.
- facility set
A facility set defines the various X.25 connection
parameters and X.25 facilities that can be negotiated for each virtual
circuit on a per-call basis.
- fast select
An optional packet-switching network facility by
which user data can be transmitted as part of the control packets that
establish and clear a virtual connection.
- FCS
Frame Check Sequence. A sequence of bits generated by X.25 at
Level 2 that forms part of the frame and guarantees the integrity
of its frame's contents. The FCS is also used by the IEEE 802.3
protocol to check the validity of frames.
- FDDI
Fiber Distributed Data Interface. A set of ANSI standards that
define a 100 Mb/s timed token passing protocol LAN that uses fiber optic
cable as the transmission medium. FDDI is a specification
for a high-speed fiber-optic ring network.
- file equation
An assignment statement used to associate a file with a specific
device or type of device during execution of a program.
- file number
A unique number associated with a file when the
file is opened. The file number is returned in the FOPEN or HPFOPEN
call used to open the file. It can be used to access that file until
the file is closed.
- file specification
The name and location of a file. The full specification
for a file includes the file name, group, and account.
- file system
The part of the operating system that handles access
to input/output devices (including those connected through the DTC),
data blocking, buffering, data transfers, and deblocking.
- flow control
A means of regulating the rate at which data transfer takes place
between devices to protect against data overruns.
- flow control negotiation
One of the network subscribed facilities selected
at subscription time. This facility allows the Flow Control parameter
to be negotiated at call set-up time, as opposed to having a predefined
value.
- formal file designator
A name that can be used programmatically or in a
file equation to refer to a file.
- FOS
Fundamental Operating System. The programs, utilities,
and subsystems supplied on the Master Installation Tape that form
the basic core of the operating system.
- full gateway
A full gateway is a node that belongs to more than
one network and has one IP address for each network. It uses store
and forward to transfer packets between each network that it belongs
to.
- gateway
A node that connects two dissimilar network architectures.
A gateway can be either a single node (full gateway) or two gateway
halves.
- gateway half
A node that works in conjunction with another node on another
network to form an internetwork. The only protocol used by gateway halves
is the NS Point-to-Point 3000/iX Link. See also
full gateway.
- gateway-half link
A link between the two nodes of a gateway-half pair. Each of the
two nodes of a gateway-half pair has a configured link (hardware
interface card) that is used for the gateway half network interface.
The NS Point-to-Point 3000/iX Link is the only link that can be
used as a gateway-half link.
- gateway-half pair
A set of two nodes that are joined by a gateway-half
link. Each node in the pair must have a gateway-half network interface
configured, using the link.
- guided configuration
A method of configuring a node in which a subset of the complete
NMMGR interface is presented, and defaults of configurable
values are used automatically.
- handshaking
A communications protocol between devices or between
a device and the CPU. Provides a method of determining that each
end of a communications link is ready to transmit or receive data,
and that transmission has occurred without error.
- hop count
See internet hop count and intranet hop
count
- host computer
The primary or controlling computer on a network.
The computer on which the network control software resides. For
HP purposes, it can also be used to distinguish the HP e3000
system (host) from the DTC.
- host-based network management
A method of managing asynchronous communications
for HP e3000 computers. All of the control software is configured
on a single host and is downloaded to the DTCs that are managed
by that host. With host-based management, a permanent relationship
exists between each DTC and the host. Terminal users can access
only the single system that owns the DTC their terminal is connected
to.
- host-based X.25
The management of X.25 network connections from
a host computer. Host-based X.25 network connections are made through
a DTC Network Access card installed in a DTC managed by the host. All
configuration is accomplished using the NMMGR utility. It is not
necessary for a PC to be part of the LAN when you are using host-based
X.25.
- HP block mode
A block mode transmission method employed by HP computers
where the system controls the block mode handshake. When HP block mode
is used, the user program need not concern itself with data transfer
protocol.
- HP PPN
Hewlett-Packard Private Packet Network. Hewlett-Packard's
own packet- switching X.25 network, which gives users full control
over the administration and security of their data
communication.
- HP TS8
A terminal server that can support up to eight asynchronous
serial connections. When used in back-to-back configuration, users
can access HP e3000 MPE/V systems on it through a DTC.
- idle device timeout
A timeout defined by the Configure: CPU command.
When the timer lapses, a device connected to the DTC user interface
that is still inactive will be disconnected.
- IEEE 802.3
A standard for a broadcast local area network published
by the Institute for Electrical and Electronics Engineers (IEEE).
This standard is used for both the ThinLAN and ThickLAN implementations
of the LAN.
- IEEE 802.3 multicast address
A hexadecimal number that identifies a set of nodes.
This address is used for multicast delivery.
- IEEE 802.3 nodal address
A unique hexadecimal number that identifies a node on
an IEEE 802.3 LAN.
- IEEE 802.5
A standard for a Token Ring network published by
the Institute for Electrical and Electronics Engineers (IEEE). This
standard is used for the Token Ring 3000/iX Network Link.
- initialization string
A sequence of control characters used to initialize
a terminal, printer, or plotter when a connection is established
from a host on the network.
- interactive communications
Processing that allows users to enter commands and data at the
terminal and receive an immediate response. Interactive processing occurs
in session mode on MPE/iX systems.
- internet communication
Communication that occurs between networks.
- internet hop count
The number of full gateways plus the number of gateway-half links
that a packet must pass through in moving from source node to
destination.
- internet protocol
A protocol used to provide routing between different local
networks in an internetwork, as well as among nodes in the same local
network. The Internet Protocol corresponds to Layer 3, the Network Layer,
of the OSI model. See also IP
address.
- internet routing
Internet routing involves all the processes required
to route a packet from a node on one network to a destination node
on another network.
- internetwork
Two or more networks joined by gateways.
- intranet communication
Communication that occurs between nodes in a single
network.
- intranet hop count
The number of intermediate nodes that lie between a source and
destination node on the same point-to-point network.
- intranet routing
Intranet routing involves all the processes required
to route a packet from one node in a network to another node in
the same network.
- intrinsic
A system routine accessible by user programs. It provides an
interface to operating system resources and functions. Intrinsics
perform common tasks such as file access and device
control.
- IP
See internet
protocol.
- IP address
Internet Protocol address. An address used by the
Internet Protocol to perform internet routing. A complete IP address
consists of a network portion and a node portion. The network portion
of the IP address identifies a network, and the node portion identifies
a node within the network.
- IP router
A node in an IP network that connects two or more
networks and provides address mapping between them. The router selects
messages from incoming buffers and places them into the appropriate
outgoing message queues.
- IP subnet mask.
See subnet mask.
- ISO
International Organization of Standards. An international
federation of national standards organizations involved in developing
international standards, including communication standards.
- LAN
Local Area Network. A collection of data communication
systems sharing a common cable whereby each system can communicate
directly with another
- LAN address
See
station address.
- LANIC
See Local Area Network Interface Controller
- LANIC physical path
The physical location (slot number) of the LANIC
within the SPU.
- LANIC Self-Test
A ROM-based program on a LANIC card that tests and
reports the status of the LANIC hardware.
- LAP
Link Access Protocol. The data link protocol specified by older
versions (prior to 1980) of X.25 at Level 2 but still permitted and
therefore usable. All new implementations of X.25 must use LAP-B, and all
old implementations must migrate to LAP-B at a future date.
- LAP-B
Link Access Protocol- Balanced. The data link protocol
specified by the 1980 version of X.25 at Level 2 that determines the
frame exchange procedures. LAP-B must also be used over direct-connect
NS Point-to-Point 3000/iX Links.
- LCI
Logical Channel Identifier. Local value on a network node which
identifies the channel used to establish a virtual circuit (SVC or PVC)
through an X.25 network.
- ldev
See logical device number.
- leased line
A data-grade telephone line leased directly to a subscriber and
allocated specifically for the subscriber's needs.
- line speed
The speed at which data is transferred over a specific physical
link (usually measured in bits or kilobits per second).
- link name
A name that represents a hardware interface card. The link name
can contain as many as eight characters. All characters except the first
can be alphanumeric; the first character must be
alphabetic.
- Local Area Network Interface Controller (LANIC)
A hardware card that fits into the backplane of
the HP e3000 computer and provides a physical layer interface
for IEEE 802.3 local area networks.
- local connection
See
direct connection.
- local node
The computer that you are configuring or that you
are logged on to.
- local switching
A feature of the DTC which permits back-to-back configuration
(for connections to an HP e3000 MPE/V host), using two ports of the same
DTC. See also closed user group.
- local user group
A list defined for a particular DTC and card that
specifies which remote nodes this DTC can send
data to and also which remote nodes this DTC can
receive data from.
- log off
The termination of a job or session.
- log on
The process of initiating a job or session.
- logging
The process of recording the usage of network resources.
Events can be logged to both the OpenView workstation and to the
MPE host.
- logging class
A number defining the severity of any given event logged. An
operator uses the logging classes to specify which events are to be
logged. Class 1 (catastrophic event) is always logged.
- logical device number (ldev)
A value by which operating system recognizes a specific
device. All DTC devices that are configured as nailed devices through
the NMMGR configuration have ldev numbers permanently assigned.
The DTC devices can then be accessed programmatically through use
of their ldev number. Non-nailed devices have ldev numbers that are
assigned from a pool of available ldev numbers for the life of their
connection to a system. Each nailed port configured in NMMGR must
have a unique ldev number.
- logon device
See session-accepting
device.
- loopback
The routing of messages from a node back to itself.
- LUG
Local User Group. A list defined for a particular DTC and card
that specifies which remote nodes this DTC can send data to and
also which remote nodes this DTC can receive data from.
See also local
user group.
- M bit
More data bit. Setting this bit in a DATA packet
indicates that at least one more DATA packet is required to complete a
message of contiguous data.
- maintenance mode
An NMMGR character mode interface used to manage both
network directory and configuration files. It can be used interactively,
from within the screen mode interface, or as a set of commands entered
via a batch job.
- map, network
A drawing that shows the topology of the network. For networks
managed by the OpenView DTC Manager a network map must be created through
use of the OVDraw capability provided with the management software. A
network map is also a hardcopy drawing used when planning a network. It
shows network topology, node and network names, addresses, network
boundaries (for an internetwork map), and link types.
- mapping
A set of characteristics that describe a route taken
by messages to reach a destination node. This set of characteristics
is configured with NMMGR at every node on a point-to-point network. One
mapping is configured at each node for every other node on the network
to which messages will be sent.
- MAU
Medium Attachment Unit. A device attached to a ThickLAN
coaxial cable that provides the physical and electrical connection
from the AUI cable to the coaxial cable.
- medium attachment unit
A device attached to a ThickLAN coaxial cable that provides
the physical and electrical connection from the AUI cable to the coaxial
cable.
- MIT
Master Installation Tape. A magnetic tape containing
the Fundamental Operating System for an HP e3000 computer.
- modem
modulator/demodulator. A device that modulates and
demodulates signals. Primarily used for modulating digital signals
onto carriers for transmission and for performing the inverse function
at the receiving end. Modems are essential for transmitting and
receiving digital signals over telephone lines.
- modulation
The process in which certain characteristics of
a carrier signal are altered in accordance with the changes of an
information-bearing signal.
- modulo
Value used as the counting cycle for determining the send
sequence number (N(S)) of frames sent across an X.25
network.
- MPE/iX
MultiProgramming Executive POSIX. The operating system of the HP
e3000 computers. The NS 3000/iX network services operate in conjunction
with the MPE/iX operating system.
- multiplexer
MUX. A device that allows multiple communication
links to use a single channel.
- nailed device
A device with a permanently assigned ldev. The assignment
is established through the system configuration of the MPE/iX host system.
Nailed devices can be accessed programmatically through their ldev number.
Nailed devices can also be assigned to more than one host.
- native mode
The run-time environment of MPE/iX. In Native Mode,
source code has been compiled into the native instruction set of
the HP e3000 computer.
- neighbor gateway
A gateway that is in the same network as a given
node.
- NetIPC
Network Interprocess Communication. Software that
enables programs to access network transport protocols.
- network
A group of computers connected so that they can
exchange information and share resources.
- network address
This can be either 1) the network portion of an
IP address as opposed to the node portion, or 2) when referring
to X.25 networks, it is a node's X.25 address.
- network boundary
The logical division between networks in an
internetwork.
- network directory
A file containing information required for one node to
communicate with other nodes in 1) an internetwork, 2) an X.25 network,
or 3) a network that contains non-HP nodes. The active network directory
on a node must be named NSDIR.NET.SYS.
- network interface
NI. The collective software that enables data communication
between a system and a network. A node possesses one or more network
interfaces for each of the networks to which it belongs. Network
interface types are LAN, router (point-to-point), X.25, Token Ring, FDDI,
VG100LAN, BT100, SNA, loopback, and gateway half. The maximum number of
supported NIs per system is 12, one of which is reserved for
loopback.
- network management
The collective tasks required to design, install,
configure, maintain, and if necessary, change a network.
- network map
A drawing that shows the topology of the network. For networks
managed by the OpenView DTC Manager, a network map must be created using
the OVDraw capability provided with the management software. A network
map is also a hardcopy drawing used when planning a network. It shows
network topology, node and network names, addresses, network boundaries
(for an internetwork map), and link types.
- Network Services
NS. Software application products that can be used
to access data, initiate processes, and exchange information among
nodes in the network. The HP e3000/iX Network Services include RPM,
VT, RFA, RDBA, and NFT.
- network subscribed facilities
A set of parameters that the user chooses when he subscribes
to the X.25 network; they include flow control negotiation, use
of D-bit, throughput class negotiation and extended packet sequence
numbering.
- network transport
Software that corresponds to layers 4 and 3 of the
OSI network architecture model. The function of this software is
to send data out over the appropriate communications link, to receive
incoming data, and to route incoming or outgoing data to the appropriate
destination node.
- NFT
Network File Transfer. The network service that
transfers disk files between nodes on a network.
- NI
See network
interface.
- NMCBACK.PUB.SYS
The default file name for the file that contains a copy of the
information contained in the configuration file
(NMCONFIG.PUB.SYS). The backup file is updated each time the
configuration file is successfully validated.
- NMCONFIG.PUB.SYS
The file that contains all of the network configuration data
for the HP e3000 computer on which it resides. It includes information
about the DTCs that can access the system as well as information about
any Network Service (NS) products running on the system. This is
the only file name allowed.
- NMDUMP
Node management services trace/log file analyzer.
A utility used to format log and trace files.
- NMMAINT
Node management services maintenance utility. A
utility that lists the software module version numbers for all HP
AdvanceNet products, including NS 3000/iX. It detects missing
or invalid software modules.
- NMMGR
Node management services configuration manager. A software
subsystem that enables you to configure DTC connectivity and network
access parameters for an HP e3000 computer.
- NMMGRVER
Node management services conversion utility. A conversion
program that converts configuration files created with NMMGR from
an earlier version to the latest format.
- NMSAMP1.PUB.SYS
A sample configuration file supplied with FOS that can
be used as a template for DTS configuration.
- NMSTART.PUB.SYS
The file which contains maintenance mode commands executed
during NMMGR startup.
- node
A computer that is part of a network. The DTC is
also considered to be a node and has its own address.
- node address
The node portion of an IP address. The IP address
consists of a node portion and a network portion.
- node management services configuration manager
See NMMGR.
- node name
A character string that uniquely identifies each
system in a network or internetwork. Each node name in a network
or internetwork must be unique; however, a single node can be identified
by more than one node name.
- node names list
A list defined on the OpenView workstation and subsequently
downloaded to all DTCs for which it is the "owner." The list specifies
all of the HP e3000 hosts on the LAN that are accessible from the
DTCs.
- non-adjacent
Describes a node on an NS Point-to-Point 3000/iX network that is
separated from a given node by intervening or intermediate
node.
- non-nailed device
A session accepting device that is not permanently associated
with an ldev number at configuration time. When the user at such a device
logs on to an HP e3000 system, an ldev is assigned from a pool of ldevs
set aside for this purpose at configuration time. The association between
a non-nailed device and this temporarily assigned ldev exists only for
the duration of the session. One advantage of the use of non-nailed
device connections is that configuration is simplified, since it is not
required that each non-nailed device be individually
configured.
- NS 3000/iX
A Hewlett-Packard data communication product that provides
networking capabilities for HP e3000 minicomputers. NS 3000/iX
consists of a link and network services.
- NS 3000/iX Link
Software and hardware that provides the connection
between nodes on a network. Some of the NS 3000/iX links available
are the ThinLAN 3000/iX Link and its ThickLAN option, the DTC/X.25
iX Network Link, the NS Point-to-Point 3000/ iX Link, and the Token
Ring 3000/iX network link.
- NS 3000/iX Network Services
Software applications that can be used to access data, initiate
processes, and exchange information among nodes in a network. The
services are RPM, VT, RFA, RDBA, and NFT.
- NS Point-to-Point 3000/iX Link
Hardware and software necessary to create networks
in which data is transmitted from node to node over a defined route
until it reaches it destination. This technique is referred to as
store and forward. Systems in a point-to-point network are connected by
means of leased or dial-up telephone lines. HP e3000 systems
attach to the point-to-point network via HP e3000 Programmable
Serial Interface (PSI) cards that fit into the back of each system's
SPU.
- NSDIR.NET.SYS
Name of the active network directory file. See also
network directory.
- octet
An eight-bit byte operated upon as an entity.
- OpenView
HP OpenView Windows is HP's network management environment. It
provides the basic services for accessing and managing networks used by
the DTC Manager, and other applications, such as Switch/PAD
Manager, Hub Manager, etc.
- OpenView Admin
An OpenView Windows program that enables you to configure how
your OpenView Windows applications will function. For example, it enables
you to set a default map for the OpenView DTC Manager.
- OpenView Draw
An OpenView windows program that is used to draw
the network map and to label the components on it.
- OpenView DTC Manager
An OpenView Windows application that enables you
to configure, control, monitor, and troubleshoot the operation of
the datacommunications terminal subsystems on the LAN.
- OpenView Run
An OpenView windows program that covers most of
the control features used by the DTC Manager, including monitoring
and diagnostic functions.
- OpenView Windows
The set of three programs: OV Admin, OV Draw
and OV Run, running on the OpenView workstation under MS
Windows, that acts as the platform for all OpenView applications,
such as DTC Manager.
- OpenView Windows Workstation
The personal computer that provides software downloads
to enable operation of the Datacommunications and Terminal Controller
(DTC). The configuration software that runs on this workstation
is called the OpenView DTC Manager software.
- OSI model
Open Systems Interconnection model. A model of network
architecture devised by the International Standards Organization
(ISO). The OSI model defines seven layers of a network architecture
with each layer performing specified functions.
- packet
A block of data whose maximum length is fixed. The unit of
information exchanged by X.25 at Level 3. The types of packets are DATA
packets and various control packets. A packet type is identified by the
encoding of its header.
- packet exchange protocol
PXP. A transport layer protocol used in NS 3000/iX links to
initially establish communication between nodes when NetIPC socket
registry is used.
- packet-switched network name
The name of a data communication network adhering
to the CCITT X.25 recommendation. This can be a PDN or a private
network such as the HP PPN.
- PAD (Packet Assembler/Disassembler
A device that converts asynchronous character streams
into packets that can be transmitted over a packet switching network
(PSN).
- PAD name
A name of up to eight characters that is associated
with a configured PAD device. The PAD name is known to both the
DTC and the host systems that the device can access.
- PAD profile
A terminal or printer profile that specifies the
configuration characteristics for PAD-connected devices.
- partner gateway half
When gateway halves are used, two gateway halves
are required in order to provide communication between two networks.
Each is the partner of the other.
- path name
When configuring with NMMGR, you can type a string in the
COMMAND: field on a screen to branch to another screen. Each
screen has a unique path name that corresponds to its location in the
hierarchy of configuration screens presented by NMMGR.
- PDN
Public data network. A data communication network
whose services are available to any user willing to pay for them.
Most PDNs use packet switching techniques.
- point-to-point
A link that connects either two nodes in a NS Point-to-Point
3000/iX network or two gateway halves.
- port
An outlet through which a device can be connected to a computer,
consisting of a physical connection point and controlling hardware,
controlling software, and configurable port characteristics. Ports
can be thought of as data paths through which a device communicates
with the computer.
- Precision Architecture
The hardware design structure for the HP e3000 computer
family.
- printer name
A character string of up to 16 characters specified
in the DTC Manager configuration (for networks using OpenView Network
Management) to define a printer by name. Can be shared by several
printers (port pool).
- printer profile
A set of configuration characteristics that can be associated
with one or more printers through the NMMGR configuration.
Printer profile specifications include the printer type, line speed,
device class assignment, and other values relevant to printers connected
through a DTC.
- printer type
A collection of characteristics that cause a printer connected to
an HP e3000 system to act and react in a specified manner. You can
configure a printer to use one of the system-supplied printer types, or
you can create custom printer types using workstation
configurator.
- privileged mode
A capability assigned to accounts, groups, or users allowing
unrestricted memory access, access to privileged CPU instructions,
and the ability to call privileged procedures
- probe protocol
An HP protocol used by NS 3000/iX IEEE 802.3 networks to obtain
information about other nodes on the network.
- probe proxy server
A node on an IEEE 802.3 network that possesses a network
directory. A probe proxy server can provide a node with information about
other nodes on the same or other networks of an
internetwork.
- profile
A method of grouping device connection specifications
and characteristics so that the set of characteristics can be easily
associated with groups of like devices. See also printer
profile, terminal profile.
- program captive device
See programmatic
device.
- Programmable Serial Interface
PSI. A hardware card that fits into the backplane of
the HP e3000 computer. It provides a physical layer interface
for NS Point-to-Point 3000/iX Links.
- programmatic device
A device operating under control of a program running
on a computer. Programmatic devices can be used for input, output,
or both, depending on the device and how it is opened by the controlling
program.
- protocol
A set of rules that enables two or more data processing entities
to exchange information. In networks, protocols are the rules that govern
each layer of network architecture. They define which functions are to be
performed and how messages are to be exchanged.
- PSN
Packet-Switching Network. Any data communication network in which
data is disassembled into packets at a source interface and reassembled
into a data stream at a destination interface. A public PSN offers the
service to any paying customer.
- PSS
Packet-Switching System. The national public PSN
of the United Kingdom.
- PVC
Permanent Virtual Circuit. A permanent logical association
between two physically separate DTEs that does not require call
set-up or clearing procedures.
- PXP
See packet exchange
protocol.
- Q bit
Qualified bit. When set in DATA packets the Q bit
signifies that the packet's user data is a control signal
for the remote device, not a message for its user.
- QuickVal
A software program that tests whether Network Services
are operating correctly between nodes.
- RDBA
Remote data base access. A network service that
allows users to access data bases on remote nodes.
- reachable network
A network that can be accessed (with additional
internet hops possibly required) by a particular gateway.
- remote connect device
An asynchronous device that is indirectly connected to a DTC
through a modem and telephone hook-up or through a PAD.
- remote node
Any network node that is physically separate from
the node you are currently using or referring to.
- retransmission count (N2)
The maximum number of times a frame will be retransmitted
following the expiration of the Retransmission Timer, T1.
- retransmission timer (T1)
The length of time that a transmitter will wait for an
acknowledgment from a destination address before attempting to retransmit
a frame. When choosing this value, factors like the line speed and
maximum frame size should be taken into account.
- RFA
Remote file access. A network service that allows
users to access file and devices on remote nodes.
- RMP
Remote Maintenance Protocol. HP proprietary protocol
used in DTC management.
- router network
See point-to-point.
- routing
The path that packets or fragments of a message
take through a network to reach a destination node.
- RPM
Remote Process Management. A network service that allows a
process to programmatically initiate and terminate other processes
throughout a network from any node on the network.
- RS-232-C
The Electronic Industries Association (EIA) Level
1 protocol specification that defines electrical circuit functions
for 25 connector pins. HP provides two implementations of this standard:
a 3-pin version for direct connections up to a distance of 15 meters (50
feet), and a version which makes use of additional circuits and
can be used for either modem or direct connections.
- RS-422
The Electronic Industries Association (EIA) Level
1 protocol specification implemented by HP in a 5-pin version which
can be used for direct device connection up to a distance of 1500
meters (4000 feet).
- security string
An alphanumeric character string that functions
as a password for dial links. The security string is used by the
dial IP protocol.
- serial device
Any device that is attached to and communicates
with a computer by means of a serial transmission interface. Terminals,
printers, and plotters are among the devices that communicate serially
with HP e3000 computers.
- serial transmission
A method of transferring data in which characters
are transmitted one bit at a time and received one bit at a time
in the order of transmission. This transmission scheme is employed
by devices connected to the system via the DTC.
- session-accepting device
A terminal or personal computer running in terminal- emulation
mode that is able to establish an interactive (conversational) session
with an HP e3000 computer. Also referred to as a logon
device.
- shared dial
A dial link that provides connection to more than
one remote system, although to only one at a time.
- shared-line access
The feature that allows two or more HP e3000
hosts to use the same DTC/X.25 Network Access card on a DTC to access
an X.25 network.
- SIC
Serial Interface Card. A card installed in the front
of the DTC that acts as an interface between a corresponding Connector
Card (CC) and the DTC's processor.
- slaved device
A device that shares the same DTC port as another
device and is connected, to the other device, referred to as its
master, by a cable. The actions of the slaved device are controlled
by the master device.
- SNMP
Simple Network Management Protocol. An industry standard for
managing networked computers in a multi-vendor environment.
- SNMP agent
A network node, such as a DTC, that is able to respond
to SNMP requests.
- SNMP manager
A network management platform that is running software
which allows it to manage SNMP nodes.
- SNP
Synchronous Network Processor card; an alternative
name for an X.25 board.
- spooled device
A printer that is accessed through the spooling
facility. The spooling facility allows a nonsharable device to be shared
among several users by temporarily storing output data on disk and
managing the selection of output spool files destined for the spooled
device.
- start bit
A data bit used to signal the start of a character
being transmitted in an asynchronous communication mode.
- station address
A link-level address used by the IEEE 802.3 protocol
that is assigned to every node on an IEEE 802.3 network.
- stop bit
A data bit used to signal the end of a character
being transmitted in an asynchronous communication mode.
- store-and-forward
A technique in which messages are passed from one node to another
in a network to reach their destination. Point-to-point networks use the
store-and-forward technique to transmit messages.
- subnet
Another name for a network, especially if the network
is part of an internetwork. The word subnet is also a synonym for
intranet.
- subnet mask
Grouping of bits that determines which bits of the
IP address will be used to define a subnetwork. The subnet mask
is configured using the NMMGR utility and specified in the same format
as an IP address.
- SVC
Switched Virtual Circuit. The path through an X.25
network that is established at call set-up time.
- switching
See DTC
switching.
- Switching user interface
The user interface available when DTC switching is enabled that
allows terminal users to choose the HP e3000 computer with which they
want to establish a communication link.
- synchronous
A mode of operation or transmission in which a continuous data
stream is generated without intervals between characters. The data stream
is synchronized by clock signals at the receiver and transmitter. As a
result, fast transmission speeds (above 9600 bps) are
attainable.
- SYSGEN
The software program that allows you to configure
the operating system on HP e3000 computers.
- system configuration
The method for telling the operating system what peripheral I/O
devices are attached and what parameters are required for system
operation.
- TCP
See transmission
control protocol.
- telenet
A proprietary public data network in the USA.
- TermDSM
Terminal online diagnostic system manager. A utility
that provides diagnostic services for DTC connections by means of
a series of commands accessible through the SYSDIAG utility. TermDSM
is used only when DTCs are managed by a host system.
- terminal name
A character string of up to 16 characters specified
in the OpenView DTC Manager configuration (for networks using OpenView
Network Management) to define a terminal by name. It can be shared by
several terminals (pool port).
- terminal profile
A set of configuration characteristics that can be associated
with one or more terminals through the NMMGR configuration. Terminal
profile specifications include the terminal type, line speed, device
class assignment, and other values relevant to terminals connected
through a DTC.
- terminal type
A collection of characteristics that cause a terminal connected
to an MPE system to act and react in a specified manner. You may
configure a terminal to use one of the system-supplied terminal types, or
you can create custom terminal types using the workstation
configurator.
- ThinLAN
A LAN that conforms to the IEEE 802.3 Type 10 BASE 2
standard LAN.
- ThinLAN 3000/iX Link
Hardware and software necessary to create a broadcast network,
which uses the IEEE 802.3 LAN cable to transmit messages to all the nodes
on the network. The messages are then accepted only by the node or nodes
to which they are addressed. Also includes the ThickLAN
and StarLAN 10 options.
- throughput class
A value assigned to a given virtual circuit that
defines how many network resources should be assigned to a given
call. It is determined by the access line speed, packet and window
sizes, and the local network's internal mechanisms.
- throughput class negotiation
One of the network subscribed facilities defined
at subscription time. This allows the user to negotiate the throughput
class at call set-up time.
- timer (T3)
The length of time that a link can remain in an
idle state. After the expiration of the timer, the link is considered
to be in a non-active, non-operational state and is automatically reset.
The value should be chosen carefully. In particular, it must be
sufficiently greater than the Retransmission Timer (T1) so that no
doubt exists about the link's state.
- Token Ring
A collection of data communication systems sharing
a common cable and communicating by means of the IEEE 802.5 protocol.
In a Token Ring network, access is controlled by the passing of
a token from node to node. Outgoing messages are attached to the
token and passed with the token until they arrive at the node to
which they are addressed.
- Token Ring 3000/iX Network Link
Hardware and software required to connect a HP e3000
system to a Token Ring network.
- topology
The physical arrangement of nodes in a network.
Some common topologies are bus, star, and ring.
- Transmission Control Protocol
TCP. A network protocol that establishes and maintains
connections between nodes. TCP regulates the flow of data, breaks
messages into smaller fragments if necessary (and reassembles the
fragments at the destination), detects errors, and retransmits messages
if errors have been detected.
- Transpac
The national public PSN of France.
- transparent mode
A data transfer scheme in which only a limited number
of special characters retain their meaning and are acted on by the
system. All other characters are considered to be data and are passed
through with no control actions being taken.
- transport, network
Software that corresponds to layers 4 and 3 of the OSI network
architecture model. It sends data out over the communications link,
receives incoming data, and routes incoming or outgoing data
to the appropriate destination node.
- TTUTIL
Also known as the Workstation Configurator. A program,
TTUTIL.PUB.SYS, on the HP e3000 that is used to create and
modify terminal and printer type files.
- Tymnet
A proprietary public data network in the USA.
- typeahead
A facility that allows terminal users to enter data
before a read is actually posted to the terminal.
- unacknowledged frame number (K)
The number of frames that can be transmitted without receiving an
acknowledgment from the destination address. When this number (K) frame
is reached, the same K frames are retransmitted.
- unedited mode
See transparent
mode.
- uninterruptible power supply
A hardware device that protects equipment from power failures and
contains an internal storage battery to supply reserve
power.
- UPS
See uninterruptible
power supply.
- V-Series (V.##) CCITT
A set of CCITT recommendations related to data communication
over a voice-grade telephone network.
- V.24
The CCITT recommendation that defines the function
of the interchange circuits between a DTE and a DCE.
- validation
The process of ascertaining whether the network
transport configuration file has been correctly configured. In guided
NMMGR, you do this by pressing the Validate Netxport key.
- VAN
Value-Added Network. A data communication network
that uses and pays for facilities belonging to another carrier. The
value-added package is then sold to a user.
- VC
See virtual
circuit.
- virtual circuit
A logical association between two physically separate
DTEs.
- virtual terminal
A network service that allows a user to establish
interactive sessions on a node.
- VPLUS
Software used to generate screens such as those
displayed by NMMGR.
- VT
See virtual
terminal.
- WAN
Wide Area Network. A data communications network of unlimited
size, used for connecting localities, cities, and
countries.
- workstation configurator
A utility (TTUTIL) that allows users to create customized
terminal and printer types by entering data through a series of VPLUS
screens.
- X.21
Defines the physical interface between a DTE and
a DCE of a public data network where the access to the network is made
over synchronous digital lines.
- X.25
Defines the interface between a DTE and a DCE for
packet mode operation on a public data network (PDN).
- X.25 address
The X.25 address provided by the network administration
if you are connected to a public data network (PDN).
- X.25 address key
An X.25 address key is a label that maps a node's
IP address to its X.25 address and its associated X.25 parameters.
You have a combined maximum of 1024 X.25 address keys in the SVC
and PVC path tables.
- X.25 iX System Access
The software that works in conjunction with the
DTC/X.25 Network Access software to provide access to X.25. The
software resides on an HP e3000 host and is configured
through use of NMMGR. To configure access to an X.25 network, you
must configure two software components: the X.25 iX System Access
(residing on the HP e3000 host), and the DTC/X.25 Network Access.
DTC/X.25 Network Access is configured through use of the OpenView DTC
Manager software for systems using PC-based network management or through
NMMGR for systems using host-based network management.
- X.25 LUG address
X.25 address of a node belonging to a LUG.
- X.29
Defines the interface for data exchange between
a packet-mode DTE and a remote packet assembly/disassembly (PAD)
facility over a packet-switching network.
- X.3
Defines the user facilities that should be internationally
available from a packet assembler/disassembler (PAD) facility, when
this is offered by a public data network.
- X.Series (X.##) CCITT recommendations
A set of recommendations for data communication networks
governing their services, facilities, and terminal equipment operation
and interfaces.
- XON/XOFF protocol
The flow control used by MPE/iX systems to protect against data
overruns. XON/XOFF protocol is controlled by the data recipient who sends
an XOFF character (ASCII DC3) to the sender if it is unable to continue
to receive data. The sender suspends transmission until it receives an
XON character (ASCII DC1).
|