Introduction to Networking for NonStop S-Series Servers

Communications Product Concepts and
Components
Introduction to Networking for HP NonStop S-Series Servers—520670-005
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Interfaces
File-System and Standards-Based Interfaces
The majority of HP communications products have file-system interfaces. That is, your
application communicates with the target device or line by making file-system calls.
The file system sends the request to the appropriate process. Although the exact
operation of some procedures is product-dependent and protocol-dependent, there is
still considerable similarity among these interfaces.
A few products have standards-based interfaces instead of file-system interfaces;
instead of file-system calls, your application uses procedures that map directly to a
standard interface. (Most standards describe functions rather than interfaces, but in
some cases a specific interface is common enough to be regarded as standard.)
If you have used another vendor’s implementation of the same interface, a
standards-based interface should be quite easy for you to learn, and your applications
should be able to migrate reasonably quickly. OSI/AS, OSI/FTAM, and NonStop
TCP/IP all have standards-based procedural interfaces.
Management Interfaces
Subsystems also include the following types of management interfaces:
Subdevices
A concept common to almost all communications subsystems is that of the subdevice.
Subdevices are defined if a subsystem potentially operates on numerous, separately
addressable objects, such as stations on a multipoint line or X.25 virtual circuits. The
line is considered a device; the stations or virtual circuits are subdevices. The concept
is also applied in other ways; even a product that does not manage real devices or
lines can have subdevices. For example, a management or diagnostic subdevice might
serve as the abstract recipient of management or diagnostic requests.
A subdevice is actually just a way of relating a group of requests. An application that
wishes to use a particular subdevice, or an operator who wishes to control or inquire
about the subdevice, refers to it by name. For example, communications subsystems
that support multipoint lines normally allow the stations on those lines to have different
Interactive Every communications subsystem has an interactive
command interface. Most communications subsystems share
a command interpreter; a few have their own.
Programmatic Several communications subsystems have a programmatic
command interface, which allows you to write management
applications that automate operator functions.
Event
Management
All communications subsystems report significant events,
such as hardware malfunctions, to a common location from
which you can retrieve the information interactively or
programmatically.