OSI/AS Configuration and Management Manual

Introduction
OSI/AS Configuration and Management Manual—424119-001
1-6
OSI/AS Subsystem Components
You can have several OSI/AS subsystems within one Compaq NonStop system.
Figure 1-3 on page 1-5 illustrates a single OSI/AS subsystem. The figure shows a
complete set of the components that work together to provide OSI services. Each
subsystem consists of:
•
Processes to handle OSI protocols and provide layer services
°
One or more NSP (network service provider) processes to handle the OSI Data
Link Layer (Layer 2) and Network Layer (Layer 3) protocols and to provide
Network Layer services (X25AM or TCP/IP) and Data Link Layer services
(TLAM for D-series or PAM for G-series).
°
One or more TSP (transport service provider) processes to handle OSI Transport
Layer (Layer 4) protocols and Network Layer (Layer 3) protocols, and to
provide Transport Layer services. The Network Layer protocols handle the OSI
internet protocol (IP), the end system to intermediate system (ES-IS) routing
exchange protocol for local area networks, and the subnetwork dependent
convergence function (SNDCF) for wide area networks.
°
One or more TAPS (application, presentation, and session service provider)
processes to handle the OSI Session Layer, Presentation Layer, and ACSE
protocols (Layer 5 through Layer 7), and to provide OSI session, presentation,
and ACSE services.
•
Exactly one OSI manager process.
•
A Management Information Base (MIB) that the OSI manager process uses to store
and retrieve configuration information, and application names and their associated
OSI addresses.
The OSI manager process and the subsystem processes registered to it constitute a single
OSI/AS subsystem. The configuration information stored in the MIB specifies which
individual processes at different layers bind to service specific user requests.
NSP, TSP, and TAPS processes provide OSI layer services and peer protocols. A single
subsystem can have many instances of each of these process types. When you build an
OSI/AS subsystem, you must register each NSP, TSP, and TAPS process with the OSI
manager process.
All processes within the same subsystem use the Guardian system procedures to
communicate with one another. Each process is thus independent of any other with
respect to its location within a single NonStop system, or an Expand or FOX network of
NonStop systems. This modularity allows you considerable flexibility in designing the
configuration of a particular subsystem. (Naturally, there are performance penalties
when subsystem components are separated by network connections.) In systems using
D-series releases of the NonStop Kernel operating system, all TSP and TAPS processes
can run as high PIN (process identification number) processes.