Expand Configuration and Management Manual (G06.24+)

Glossary
Expand Configuration and Management Manual—523347-008
Glossary-15
passthrough routing
over-ATM line-handler process. See also active connect request and network access
method (NAM).
passthrough routing. A routing scheme used by the Expand subsystem that permits
intermediate nodes to route, or passthrough, data packets to the destination system.
This scheme reduces the number of lines required between systems because systems
do not have to be directly connected.
passthrough traffic. Packets received from a remote node that are destined for another
remote node. See also passthrough routing.
path. One or more lines between two adjacent nodes. See also route and best-path route.
path function. One of the two functions of an Expand line-handler process. A single-line
Expand line-handler process performs both path and line functions with a single logical
device. A multi-line path requires a logical device to manage the path function and a
separate logical device for each line in the path.
path logical device. A logical device that manages the path function for a multi-line path.
permanent virtual circuit (PVC). A virtual circuit that is permanently established. PVCs
save bandwidth associated with circuit establishment and tear down in situations
where certain virtual circuits must exist all the time. See also switched virtual circuit
(SVC) and ATMSAP connection.
persistence. The capability of a generic process to restart automatically if it was stopped
abnormally.
persistence manager. A process named $ZPM that starts generic processes and manages
their persistence.
physical unit (PU). In the Systems Network Architecture (SNA), the component that
manages and monitors the resources of a node.
PIN. See process identification number (PIN)
.
port number. A 16-bit address used to select a socket on a host. The Transmission Control
Protocol (TCP) and the User Datagram Protocol (UDP) add to the Internet Protocol (IP)
the capability of having several simultaneous sessions with a given host. Multiple
sessions are accommodated by specifying a port number, which identifies the
communications path, along with the IP address. Each end of a communications path
is assigned a port number for that session. See also Internet Protocol (IP) address
.
process. A program that has been submitted to the operating system for execution or a
program that is currently running in the computer.
process ID. A number that uniquely identifies a process. It consists of the processor
number and the process identification number (PIN).