Synonym for FIFO special
file (so named because it is a pipe that is located in the file system
by its name so that different processes can find it).
namespace
A unique identifier used for
qualifying element and attribute names used in XML. A namespace allows
you to retain unique element names by simply providing a two-part naming
system through the use of element names associated with a Universal Resource
Identifier (URI). The specific location may not actually contain any
data about the tags, but simply allows more than one use of a specific tag
name. For example, if you are using more than one DTD and both have a
<firstname> element, you can distinguish between the two by
using namespaces. For more information, go to the W3C Web site (http://www.w3.org/).
NAT
Network address table.
native console
A locally attached system
console.
NAU
Network addressable unit.
NCB
Node control block.
NCB control record
A fixed-file record that
contains information about the node control block (NCB) directory
records.
NCB directory record
A fixed-file record
that contains the names of dynamic LU resources and the addresses of the
381-byte long-term pool file node control block (NCB) records assigned to
those resources.
NCB reconciliation function
A function that
returns to the TPF system the node control block (NCB) directory record
entries and NCB records that are no longer being used.
NCB reorganization function
A function that
changes the number of node control block (NCB) directory records in the TPF
system.
NCB slot
A field in an node control block
(NCB) directory record entry that contains the address of a 381-byte long-term
pool file NCB record for a dynamic LU resource. There are 8 NCB slots
for each dynamic LU resource.
NCE
Network connection endpoint.
NCP
Network Control Program.
NEF
Network extension facility.
nested scope
In TPF transaction services, a
commit scope within a commit scope. A nested commit scope begins when a
higher-level commit scope is already active.
network address table (NAT)
The SNA table
that contains the network addresses of all local TPF LUs and remote LUs that
the TPF system has discovered dynamically.
network addressable unit (NAU)
In SNA, a
logical unit, physical unit, or system services control point; it is the
origin or the destination of information transmitted by the path control
network.
network byte order
The byte order required
for all binary integers in TCP/IP headers as they traverse a network.
In this format, the 4 bytes in a 32-bit value are transmitted in the following
order: bits 0-7 first, then bits 8-15, then bits
16-23, and bits 24-31 last. Machines that store binary
integers in other formats must convert the header values into the network byte
order before transmitting the data. See also host byte order
and dotted decimal notation.
network connection endpoint (NCE)
The
component in a high-performance routing (HPR) endpoint that processes network
layer packets (NLPs) received over rapid transport protocol (RTP)
connections. The last label in the automatic network routing field
(ANRF) is always an identifier for an NCE in the destination node.
Network Control Program (NCP)
An IBM
licensed program that provides communications controller support for
single-domain, multiple-domain, and interconnected network capability.
network extension facility (NEF)
An
extension of ACF/NCP/VS (a separate IBM licensed program) that allows ALC
devices to attach to a 37x5 running under NCP control.
network layer header (NHDR)
The part of the
network layer packet (NLP) that contains the automatic network routing (ANR)
labels, among other information, and is used by the network to route the NLP
from one rapid transport protocol (RTP) endpoint to another.
network layer packet (NLP)
A message unit
used to carry data between high-performance routing (HPR) nodes. An NLP
contains a network layer header (NHDR), transport header (THDR), and
optionally data.
new-line character
A control character that
causes the print or display position to move to the first position on the next
line. This control character is represented by '\n' in the C
language.
NHDR
Network layer header.
NLP
Network layer packet.
node
An endpoint of a link or a junction
common to two or more links in a network. Nodes can be processors,
controllers, or workstations, and they can vary in routing and other
functional capabilities. (OSF) In a tree structure, a point at which
subordinate items of data originate. (A) In SNA, an endpoint of a link
or a junction common to two or more links in a network. Nodes can be
distributed to host processors, communication controllers, or
terminals. Nodes can vary in routing and other functional
capabilities. In ACF/VTAM, a point in a network defined by a symbolic
name.
node control block (NCB) record
A record
that contains information about the message queues for an LU resource.
nonavailable state
The state a coupling
facility (CF) is in when only certain CF commands are processed normally;
all other CF commands are suppressed. Contrast with available
state. See coupling facility (CF).
nonblocking mode
Control is returned to the
caller of a socket API function even if its request is not satisfied.
For example, for a read or recvfrom function call, the
operating system does not suspend the application program if data is not
available to satisfy the request. However, a return code of -1 is
returned to the application program. See blocking
mode.
nonduplicated file
A design for a TPF
database where none of the records have duplicate copies.
nonfresh load
The part of SNA restart that
is activated on most hardware and software IPLs. All SNA tables will be
reloaded from their file copies. Contrast with fresh
load.
nonpersistent message
A message that does
not survive a restart of the queue manager. Contrast with
persistent message.
nonunique collections
Collections that can
contain elements that have the same value (such as bags and logs) or the same
key (such as dictionaries and key bags).
NORM state
The most active of the 5 system
states. All functions are available, communication lines are active,
and all types of entries are processed.
notify lock structure
On a coupling facility
(CF) this structure maintains lock granted and lock contention
information.
NPSI
X.25 NCP Packet Switching
Interface.
NSI
Next sequential instruction.
NULL
A pointer guaranteed not to point to a
data object.
null character (NULL)
The character with the
hex value 00 (all bits turned off).
null statement
A C statement that consists
solely of a semicolon.