Introduction to Networking for NonStop S-Series Servers

Application Programming With Communications
Products
Introduction to Networking for HP NonStop S-Series Servers—520670-005
3-2
Application Architecture Examples
Application Architecture Examples
NonStop S-series servers and Expand networks lend themselves to many kinds of
applications with different communications requirements. Figure 3-1 on page 3-3,
Figure 3-2 on page 3-5, and Figure 3-3 on page 3-7 illustrate some possible kinds of
applications and the HP products and interfaces that might be used to accomplish
them. The accompanying text describes the programming tasks the sample
applications imply.
These examples are similar, but not identical to, real applications and are meant for
illustration only. The application designs and the products used to realize them are not
necessarily the best ones for your application. In fact, you will often have many
products and interfaces from which to choose. Your selection will depend on the
equipment you have, your performance requirements, and the amount of control you
want to have over the communications part of your application.
Figure 3-1 illustrates the use of the Expand network and the Pathway environment to
automate a substantial part of a telecommunications business, including the integration
of related applications.
Figure 3-1 on page 3-3 shows nine NonStop S-series servers. Several of these servers
are dedicated to specific telecommunications or administrative applications, and two
are communications servers controlling a network of many kinds of terminals. Each
application has two parts: a terminal interface part that runs on one of the
communications servers, and a database management part that runs on a
departmental server.
For example, the database management part of the billing application runs on the
server in the accounting department. The applications are integrated in the sense that
they are selections on a common operator interface and are able to share data by
using one another’s server processes when appropriate.
Most of the programming for this kind of environment is on an extremely high level.
The network is transparent, and the device connection requirements of the IBM 3270
terminals are virtually transparent to programmers (because the Pathway environment
supports them transparently). The only communications programming the example
requires is the development of a front-end process that supports hand-held terminals.
This process receives data from the Pathway/iTS requester, modifies the data as
required by the terminal device, and passes the data to the device through the
ATP6100 asynchronous terminal process. Conversely, it accepts data from the device
through ATP6100 and modifies it before passing it to the Pathway/iTS requester.
The label IDS on the diagram refers to the Pathway/iTS intelligent device support
feature, which provides for the exchange of messages between a Pathway application
and a specialized device.