Introduction to SNA Capabilities of Tandem NonStop Systems

Applications
Introduction to SNA Capabilities of Tandem NonStop Systems–134597
4-3
Off-the-Shelf Applications
Off-the-Shelf Applications
Many applications marketed by Tandem Alliance partners are designed to run with
SNAX access methods. Table 4-1 lists some of these applications, while Appendix A
provides details of these and others. Some applications use more than one form of
SNAX connectivity, such as serving a network of ATMs and providing file transfer to a
back-office host.
Developing Your Own Applications
Applications using SNAX APIs must run in the Guardian environment, typically as
Pathway applications. You must choose the SNAX API best suited to your
communications needs:
1. For bulk file transfer between a Tandem system and an SNA host, you may use
Exchange/SNA.
2. For all other application-to-application communications, SNAX/APC is
recommended. LU-LU session type 6.2 implements IBM’s advanced program-to-
program communication (APPC), which has specific benefits over alternatives
(such as LU-LU session type 0). In a type 2.1 node (SNAX/APN) environment,
SNAX/APC allows efficient use of session resources through:
•
Multiple sessions (each LU can engage in several sessions with other LUs)
•
Parallel sessions (each LU can engage in several sessions with the same partner
LU)
•
Change number of session (CNOS) verbs
SNAX/APC also provides mapped conversation verbs (which makes programming
easier) and conversation-level security (sending of a user identification and
password).
3. For a program to communicate with multiple device types, SNAX/HLS provides
maximum flexibility.
4. For a program to communicate with a specific type of device, you can use an API
that supports the specific LU-LU session type for that device. Table 4-2
shows the
most specific APIs for some common device types.