SNAX/XF and SNAX/APN Configuration and Management Manual

Glossary
SNAX/XF and SNAX/APN Configuration and Management Manual—425836-005
Glossary-16
Pathway application
Pathway application. A set of programs that perform online transaction processing tasks in
the Guardian environment, using interfaces defined by HP.
PDN. Public data network.
peer. An entity that communicates as an equal with another entity at the same protocol
level.
peripheral node. See SNA peripheral node.
Peripheral Utility Program (PUP). A utility used in D-series and earlier RVUs to manage
disks and other peripheral devices. In G-series RVUs, PUP functions are performed by
the Subsystem Control Facility (SCF).
permanent virtual circuit (PVC). An X.25 virtual circuit that has a logical channel
permanently assigned to it at each end. Contrast with switched virtual circuit.
physical unit (PU). That part of a device (hardware or software) that provides control
functions for its own node and for the other less intelligent device nodes attached to
the PU.
PIU. See path information unit (PIU).
PLU. See primary logical unit (PLU).
point-to-point line. A telecommunications line that connects one node to one other node.
port. An entity that provides a SNAX/XF line with access to an X25AM subdevice. The
X25AM subdevice provides access to an X.25 network using the QLLC protocol. Up to
254 ports can be configured in an SCF DEVICE command and can be controlled using
SNAX/CM (Connection Manager) for each SNAX/XF switched X.25 line. Each port is
controlled independently and can support the connection of one switched PU. One
ENABLE or one CONNECT connection can be active for each port.
preferred path. The preferred path is the path the WAN subsystem uses unless it is
unavailable, in which case the alternate path is used. The preferred path is configured
in the WAN Subsystem Control Facility (SCF) product module with the ADD DEVICE
command
primary link station. In SNA, the station on a link responsible for control of the link. A link
has only one primary link station. All traffic over the link is between the primary link
station and a secondary link station. Contrast with secondary link station.
primary logical unit (PLU). The logical unit that controls an LU-LU session. Within each
LU-LU session, one of the LUs is the primary and the other is the secondary. The most
important control that the PLU exerts is the formatting and sending of the BIND request
that initiates the session.