HP-UX SNAplus2 R7 NOF Programmer's Guide

Introduction to the NOF API
SNAplus2 Resources
Figure 1–2 PU Concentration Facilities Provided by SNAplus2
Downstream
Computers
Host
Controller
SNA Node Providing
PU Concentration
The downstream computer must contain an SNA PU type 2.0 or 2.1 to support dependent LUs. For example,
the downstream computer could be a PC running Microsoft’s SNA Server for Windows NT, or another SNAplus2
computer.
Using this feature, all the data transferred between the host and the downstream computer is routed through the
SNAplus2 local node. This enables a downstream computer to share a host connection with SNAplus2 or with
other downstream computers instead of requiring a direct link. For example, you could set up several downstream
computers connected to SNAplus2 over a local Token Ring network, so that they could all access the same long-
distance leased line from SNAplus2 to the host.
Using PU concentration also simplifies the configuration at the host because there is no need to define the downstream
computers and the communications links to them. The host configuration only needs to include the SNAplus2
computer and its host communications link; the LUs at the downstream computers are configured as part of the
resources of the SNAplus2 computer. The host computer is not aware that PU concentration is being used.
1.3.3 TN Server
SNAplus2 TN server provides access to 3270 host computers for TN3270 users on other computers. The TN server
feature enables TN3270 users to share a host connection with SNAplus2 or with other TN3270 users, instead of
requiring a direct link. It also enables TN3270 users to access hosts that are not running TCP/IP.
Figure 1–3, SNAplus2 TN Server, illustrates the SNAplus2 TN server function:
46