OSI/MHS P7 Application Programmatic Interface (P7 API) Manual

Glossary
OSI/MHS P7 Application Programmatic Interface (P7 API) Manual—424825-001
Glossary-24
RTS (reliable transfer service) process
RTS (reliable transfer service) process. A process in the MR group that implements the
RTSE protocol and accesses the PDU store to read and write messages.
RUA (remote user agent). A user agent that submits and retrieves messages through a
message store and resides on a system or device other than the system that provides the
message store. See also LUA.
SAP (service access point). In OSI, a logical location between two layers, through which the
services of the lower layer are made available to local users, and those of the upper layer
are made available to remote systems. (The SAP is always named after the lower layer;
for instance, an SSAP is between the Session and Presentation Layers.) For the Network
Layer and below, local users and remote systems use the Network Service Access Point
(NSAP) address to establish and maintain connections. For the Transport Layer and
above, local users and remote systems do not use SAP addresses explicitly; rather, they
specify an address called the “(N)-address,” consisting of one or more selectors. See
also selector.
S-selector. See SSEL.
SC (store cleaner) process. A process that scans the MR group PDU store periodically and
removes messages that have been fully processed.
SCF (Subsystem Control Facility). A part of DSM, used to provide a common, interactive
management interface for configuring, controlling, and collecting information from
Compaq data communications products.
SCP (Subsystem Control Point). In DSM, the management process for all Compaq data
communications subsystems. There can be several instances of this process.
Applications using SPI send all commands for data communications subsystems to an
instance of this process, which in turn sends the commands on to the manager processes
of the target subsystems. SCP also processes a few commands itself. It provides
security features, version compatibility, support for tracing, and support for applications
implemented as NonStop process pairs.
segment. See string segment.
selector. In OSI, an address component that refers to one or more service access points
(SAPs) of the Transport, Session, or Presentation Layer and is used to establish and
maintain connections. Remote systems and local users specify the selectors as part of an
address called the “n-address.” See also SAP.
send file. In the P7 API, a file used for sending data to the OSI/MHS subsystem. The file
number is returned by a call to the LOS_OPEN_ procedure. See also result file.
sensitive command. In DSM, a command that can be issued only by a restricted set of
operating system users, such as the owner of a subsystem process. For Compaq data
communications subsystems, the sensitive commands are those that can change the state
or configuration of objects, start or stop tracing, or change the values of statistics
counters. See also nonsensitive command.