HP-UX SNAplus2 R7 General Information

SNA Networking

SNA and APPN

Figure 1–2 Portion of a Sample APPN Network

EN1

LEN1

Legend

EN - End Node

NN - Network Node

LEN - Low-Entry Networking Node

EN3

NNE

EN2

NND

NNC

NNA

NNB

Host

APPN Network

Subarea Network

Controller

Except for LEN nodes, each node in an APPN network contains a control point (CP) that is responsible for managing

the node and its resources. A CP in one APPN node can establish a session with the CP in an adjacent node. These

CP-CP sessions are used to exchange network information that enables resources to be located dynamically.

APPN networks include the following types of nodes that provide different levels of connectivity and networking

support:

LEN Nodes

A low entry networking (LEN) node is a type 2.1 node. It contains the most basic functionality necessary

for connection to an APPN network.

LEN nodes do not contain control points and so cannot establish CP-CP sessions with any other node. This

means that they must be manually pre-conﬁgured with information about the remote LUs with which they

can communicate.

A LEN node can communicate using a direct point-to-point connection to any other node in the APPN net-

work. Additionally, it can communicate with a network node that provides access to other nodes in the

network. To do this, the resources on the other nodes must be conﬁgured on the LEN node as though they

were resources of the network node. If, in addition, the LEN node’s resources are conﬁgured on the network

node, other nodes in the network can locate the resources on the LEN node. In this case, the network node

acts as a network node server (NNS) on behalf of the LEN node. To the LEN node, the entire APPN net-

work appears to be located on the network node; to the rest of the APPN network, the LEN node appears to

be part of its NNS.

APPN end nodes