Introduction to SNAplus2

SNAplus2 Components

Node Components

A server running SNAplus2 implements an SNA node. It can also provide passthrough services between an SNA host and computers in an APPN or TCP/IP network.

SNA Support

SNAplus2 provides SNA node type 2.0 and 2.1 (LEN node) support for communicating with host and peer computers; it also implements an APPN node, providing end node function.

SNAplus2 implements an APPN node to communicate with other nodes on the SNA network. This provides logical unit (LU) 6.2 support for APPC and CPI-C capabilities and for 5250 emulation, in addition to LU 0, 1, 2, and 3 support for 3270, RJE, and LUA communications.

SNAplus2 can operate either as a LEN node or as an APPN end node, depending on its configuration. Certain functions are supported only on end nodes, as defined by the APPN architecture. These differences are indicated where necessary in this manual; where no differences are indicated, the information applies to both node types.

Passthrough Services

Passthrough services enable downstream computers on a LAN to access host resources through a server running SNAplus2. SNAplus2 provides the following passthrough services:

•PU concentration (see “PU Concentration”).

•Dependent LU requester (see “Dependent LU Requester”).

•TN server (see “TN Server”).

•UNIX command facility (see “Remote Command Facility”).

PU Concentration. In addition to providing direct access to a host computer, SNAplus2 can provide PU concentration facilities. This feature enables other computers to access a host computer through the SNAplus2 node, instead of requiring a separate connection to the host from each computer.

The PU concentration feature is shown in Figure 2-7, “PU Concentration.”

Chapter 2

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