Configuring SNAplus2 for Enterprise Extender

Configuring SNAplus2 for Enterprise Extender White Paper 33
APPN Nodes
Introduction
In an APPN network, nodes can be of the following types.
Network Nodes (NN)
End Nodes (EN)
Low-entry networking nodes (LEN nodes)
Branch Network Nodes (BrNN)
Each node in an APPN network is connected to at least one other node in the
APPN network. Wherever supported, CP-CP (Control Point to Control Point)
sessions are established over these connections to adjacent nodes (nodes in
the same network that can establish direct connections without going through
a third node). CP-CP sessions are used to exchange network topology
information, request the location of network resources and manage sessions.
All nodes in an APPN network share a common network name.
Network Node
A Network Node provides distributed directory and routing services for all LUs
in its “domain”, where its domain is all directly attached End Nodes and LEN
nodes that are using the services of the Network Node. The Network Node is
referred to as the Network Node Server (NNS) for those directly attached End
Nodes and LEN nodes.
A Network Node provides the following services:
¾ LU-LU session services for its local LUs
¾ Directory searches and route selection for all LUs in its
domain
¾ Intermediate session routing for sessions between LUs on
different nodes
¾ Routing for Management Services (MS) data, such as alerts,
between a served End Node or LEN node and an MS focal
point.
End Node
An End Node is an end point in an APPN network. It maintains directory
information only for local resources. An APPN End Node can independently
establish sessions between local LUs and LUs on adjacent nodes. Sessions with
LUs on nodes, not directly connected to the End Node, an End Node requests
routing and directory information from its Network Node Server using these
CP-CP sessions. End Nodes can register their local LUs with their Network Node
Server. This capability means the network operator at the Network Node
Server does not have to predefine the names of all LUs on the attached End
Nodes to which the Network Node provides services.
An End Node can be attached to multiple network nodes, but it can have CP-CP
session
s active with only one Network Node at a time, that is, with its Network
Node Server. The other Network Nodes can be used only to provide
intermediate routing for the end node or as substitute Network Node servers if
the main Network Node Server becomes unavailable.