APPC Subsystem on MPE/XL Node Manager's Guide (30294-90007)

22 Chapter1

Introduction

The APPC Subsystem

The SNA Link Product

SNA/SDLC Link/XL is made up of a Programmable Serial Interface

(PSI) card and a software module called SNA Transport. In order to

connect the HP 3000 directly to multiple remote systems, or to connect

multiple communication lines from the HP 3000 to a remote system,

you need to install multiple copies of SNA/SDLC Link/XL.

HP 3000 Node Types

The APPC subsystem, together with SNA/SDLC Link/XL, allows the

HP 3000 to function as either a Node Type 2.0 or a Node Type 2.1.As

a Node Type 2.0, the HP 3000 can communicate with a Node Type 5

(like an IBM mainframe). As a Node Type 2.1, the HP 3000 can

communicate peer-to-peer with another Node Type 2.1 (like an IBM

AS/400).

As a Node Type 2.1, the HP 3000 can participate in Advanced

Peer-to-Peer Networking (APPN). APPN is an extension to SNA that

allows Type 2.1 (peer) nodes to communicate without the intervention

of the SSCP on a host node. In an APPN network, certain nodes are

conﬁgured as Network Nodes, which perform intermediate session

routing between nodes.

The HP 3000 functions as a Low Entry Networking (LEN) node in an

APPN network. It cannot perform intermediate session routing, but if it

is connected to a Network Node, it can take advantage of the Network

Node's intermediate routing capabilities to communicate with

non-adjacent nodes (nodes not directly connected to the HP 3000).

NOTE

When you conﬁgure an IBM AS/400 to communicate with LU 6.2 API

on the HP 3000, you must conﬁgure the HP 3000 controller as a LEN

node in an APPN network.

APPC Sessions and LUs

The APPC subsystem supports 256 active APPC sessions. The

combined total of active sessions, for all LU 6.2 products running on the

APPC subsystem, may not exceed 256. Each TP conversation requires

one session.

Though conversations can be initiated locally or remotely, all APPC

sessions are controlled locally by the node manager. The node manager

can activate or deactivate sessions interactively with control operator

commands or programmatically with control operator intrinsics. The

node manager can also control the number of active sessions

automatically through conﬁguration.

APPC session parameters must be deﬁned in APPC subsystem

conﬁguration. For more information on APPC subsystem conﬁguration,

see Chapter 4 , “APPC Subsystem Conﬁguration,” in this manual.