SNAX/HLS Application Programming Manual

Glossary
Glossary–8 104707 Tandem Computers Incorporated
SSCP–PU. In SNA, a session between an SSCP and a PU that allows the SSCP to send
requests to and receive status information from individual nodes in order to control
the network configuration.
SSCP–SSCP session. In SNA, a session between the SSCP in one domain and the SSCP
in another domain. An SSCP–SSCP session is used to initiate and terminate cross–
domain LU–LU sessions.
static passthrough. A passthrough mode that allows SLUs connected to a Tandem
system to take the initiative in establishing sessions with host application programs.
With static passthrough, the host SSCP can send USS messages to devices connected to
a Tandem system.
subsystem. A process or collection of processes that give users access to a set of related
resources or services. A subsystem typically controls a cohesive set of objects.
Subsystem Control Facility (SCF). A Tandem product that is used to configure, control,
and collect information about Tandem data communications subsystems. SCF can be
used to dynamically configure and manage the entities in the SNAX/XF or
SNAX/CDF environment.
Subsystem Programmatic Interface. A Tandem product that presents a common
message–based interface used to build and decode messages for communications
between requestors on sessions. Generally used for control and enquiry functions.
See event management service. See also distributed systems management.
SPI. See subsystem programmatic interface. See also event management service. See also
Distributed Systems Management.
STSN. Set and test sequence number request. Only used by TS–profile 4.
SUT. Site update tape.
SVC. Switched virtual circuit.
switched floating LU. A LU that is subordinate to a switched floating PU. When a
switched floating PU becomes subordinate to a line, all switched floating LUs
subordinate to that switched floating PU also become subordinate to the line.
switched floating PU. A PU that is not permanently subordinate to any line, but rather is
temporarily subordinate to the Service Manager ($SSCP) until it is becomes
temporarily subordinate to a switched line because it is needed.
switched line. A telecommunications line in which the connection is established by
dialing. Contrast with nonswitched line. See leased line.
syncdepth parameter. A parameter that sets the maximum number of operations or
messages that a process is allowed to queue before action must be taken or a reply
must be performed.
SYSGEN. Tandem system generation program used to tailor the operating system for a
specific hardware and software configuration. SYSGEN is a subset of Install that
creates a system image only. The SYSGEN process can be divided into three phases: