Introduction to Networking for NonStop S-Series Servers

Communications Product Concepts and
Components
Introduction to Networking for HP NonStop S-Series Servers—520670-005
2-2
Layered Structures and Common Components
This modular product structure has three important characteristics:
•
The same higher-level component can often use any of several lower-level
components. Higher-level components and your applications are insulated from
lower-level network characteristics. Conversely, multiple components at a given
level can often use the services of the same lower-level component.
•
Application program interfaces (APIs) are usually available at several levels of
function and complexity—in fact, as Figure 2-1 on page 2-3 shows, the same
component can have APIs on several levels—letting you tailor the connection to
your needs. In effect, you can choose to perform higher-level protocol functions in
your own application. In some cases you can also replace functions within the
stack (for example, to customize a protocol for a specific kind of device) and still
use higher-level HP software, such as Transaction Services/MP (TS/MP).
•
Management interfaces are available as modules, allowing system managers (or
management applications) to examine or control subsets of the communications
resources. HP also provides management tools that present an integrated view of
all communications resources.
Layered structures are very common in implementations of communications protocols.
Other sections of this manual will show how particular HP products provide the
functions of one or more layers defined by well-known communications protocols.