Introduction to SNA Capabilities of Tandem NonStop Systems

Introduction to SNA Capabilities of Tandem NonStop Systems–134597
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Connectivity
This section describes the roles that Tandem NonStop systems using the SNAX access
methods can play in SNA networks. This discussion requires clarification of the
following terms:
access method. The input-output (I/O) process or communications subsystem that
provides applications access to a communications line.
acquire. To establish communication with a device.
control. To manage the resources of a device; for example, to activate and deactivate
the device, or to establish and terminate sessions.
device. Any equipment that is used for input or output of data, such as a display
terminal, workstation, printer, automated teller machine (ATM), or point-of-sale
(POS) terminal.
serve. To provide application and database services for a device or another application.
SNA host. An IBM mainframe or equivalent system running the Virtual
Telecommunications Access Method (VTAM) or equivalent software.
type xx node. In SNA, a classification of the nodes in a network; see the following
table:
Node Type Description
1 Peripheral node that can communicate with other nodes only with host
assistance; these are old devices with fewer capabilities than type 2.0 nodes.
2.0 Peripheral node that can communicate with other nodes only with host
assistance; for example, a cluster controller, distributed processor, or personal
computer in terminal-emulation mode.
2.1 Peripheral node that can communicate with other nodes independently of a
host; for example, a PS/2.
4 SNA communication controller (running NCP).
5 SNA host (running VTAM).