HP-UX SNAplus2 R7 General Information

Introducing SNAplus2

SNAplus2 Resources

Figure 2–1 PU Concentration Linking Multiple Downstream Workstations to a Host

Computer

PU Concentration

System/390 Host

SNA Network

AIX

Windows

OS/2

Controller

When PU concentration is used, 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 can set up several

downstream computers connected to SNAplus2 over a local token ring network, so that they all access the same

long-distance SDLC 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 needs to include only 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.

TN Server

3270 emulation programs that communicate over TCP/IP (rather than over an SNA network) are referred to as

“TN3270 programs” (Telnet 3270 emulation programs).

TN3270 programs can also include support for TN3270E (Telnet 3270 standard extensions). TN3270E supports

3270 device emulation (including both terminals and printers) using Telnet. It enables a Telnet client to select a

particular device (by specifying the LU name), and provides enhanced support for various functions, including the

ATTN and SYSREQ keys and SNA response handling.

Note

This book uses the term TN3270 to refer to information that applies equally to the TN3270,

TN3287, and TN3270E protocols.

SNAplus2 TN server provides access to 3270 host computers for TN3270 users on other computers. TN server

enables TN3270 users to share a host connection with SNAplus2 or with other TN3270 users, instead of requiring

a direct link. TN server also enables TN3270 users to access hosts that are not running TCP/IP.

The SNAplus2 TN server function is shown in Figure 2–2, TN Server.