HP HP-UX SNAplus2, Administration Manual

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50 Chapter 1
SNA Terms and Concepts
Basic APPN Concepts
Figure 1-5 LEN Node Directory
To establish a session with an LU on a node that is not directly attached,
Node LEN1 sends an LU-LU session activation (BIND) request to its
network node server (Node NNA). The server automatically locates the
destination LU and forwards the BIND.
NOTE
In this example, Node LEN1 can establish a session with LU1 on Node
EN1 through its network node server, NNA. However, LU2 on Node EN1
is not defined in the directory for Node LEN1, so Node LEN1 cannot
establish sessions with that LU.
End Node Directories.
When an LU is not represented in an end
node directory, the end node initiates a
LOCATE
search to find the desired
LU. To activate the search for a remote LU, the end node invokes the
services of its network node server. An example of an end node directory
is shown in Figure 1-6, “End Node Directory.”