Expand Configuration and Management Manual (G06.24+)

Glossary
Expand Configuration and Management Manual—523347-008
Glossary-13
network control process (NCP)
network control process (NCP). A process pair, named $NCP, that runs in each system of
an Expand network. $NCP is responsible for establishing and terminating system-to-
system connections, maintaining network-related system tables (including the network
routing table, NRT), calculating the most efficient way to transmit data to other systems
in the network, monitoring and logging changes in the status of the network and its
systems, informing $NCPs at neighbor systems of changes in line or Expand line-
handler process status, and aborting pending requests when all paths go down. $NCP
uses the services of the network utility process, $ZNUP. See also network routing table
(NRT) and network utility process.
network delay. The amount of time required to process a network request.
network diagram. A configuration diagram that shows the network systems and the lines
that connect the systems.
network routing table (NRT). A table that resides in each processor in each system in the
network. The NRT associates each destination system with the logical device (LDEV)
number of the best-path route Expand line-handler process to use to send messages
to that system. See also best-path route and network control process (NCP).
network topology. The pattern of interconnection of systems in a network. Common
network topologies include star, tree, ring, bus, mesh, and mixed.
network utility process. A NonStop Kernel input-output process (IOP), named $ZNUP,
which is used by the network control process ($NCP). $ZNUP answers requests that
require waits for system information. It also responds to requests for the time at remote
systems, the process information of remote processes, device information requests,
and traffic statistics.
node. A uniquely identified computer system connected to one or more other computer
systems in a network.
nonsensitive command. A command that can be issued by any user or program allowed
access to the target subsystem—that is, a command on which the subsystem imposes
no further security restrictions. For HP data communications subsystems, the
nonsensitive commands are all those that cannot change the state or configuration of
objects (usually informational commands). Compare sensitive command.
NonStop Cluster Switch. An assembly consisting of a ServerNet II Switch, an
uninterruptible power supply (UPS), and an AC transfer switch. The NonStop cluster
switch enables the routing of ServerNet messages across an external fabric of a
ServerNet cluster. The assembly can be packaged in a switch enclosure or in a 19-inch
rack.
NonStop Kernel. See HP NonStop Kernel.
NRT. See network routing table (NRT).
OBEY file. See communications access process (CAP).