HP-UX SNAplus2 R7 Administration Guide

Introduction to SNAplus2
SNAplus2 Resources
• Balancing the traffic from user sessions across multiple servers or multiple host links, by defining a pool
containing LUs on more than one node or on more than one host link.
• Permitting access to more than one host system from the same configuration, so that if one host system becomes
unavailable, sessions can still be established to another system without requiring reconfiguration.
Default LUs
If you are configuring type 6.2 dependent LUs for use with APPC or CPI-C applications, you may wish to define
them as members of the default pool. The default pool can include LUs from more than one node. An application
that does not specify a particular local LU is assigned an unused LU from the pool of default LUs; it can be assigned
to any of these LUs as available.
The LU does not need to be on the same computer as the application. However, if you are de
fining partner LUs for
the applications, the partner LUs must be defined on all nodes where default LUs are defined, so that the application
can contact the correct partner LU using any of the default local LUs defined on any node.
Modes and Classes of Service
A mode specifies a set of characteristics that a type 6.2 local LU uses to communicate with its partner LU. These
characteristics include information about the way data is transmitted between the two LUs (such as maximum RU
size and pacing window sizes), and about whether the LUs can establish parallel sessions.
The definition of a mode can also include the name of a class of service (COS), which specifies minimum and
maximum acceptable values for characteristics such as transmission time, transmission cost, and network security,
together with weightings associated with different ranges of these values. This enables the node to calculate the
best route across the network when two or more routes to the same remote LU are available. The configuration
of the SNAplus2 node specifies whether the node performs explicit mapping between modes and COSs. If explicit
mapping is not supported, you do not need to associate a COS with the mode; the COS name is determined
dynamically.
Directory Information
APPN network and end nodes maintain dynamic directory information about remote nodes and partner LUs. In
addition, you can configure such information directly. On a LEN node, you must configure directory entries for each
partner LU. You can also configure such resources directly on an APPN end node or network node (for example,
to eliminate the need for a network node to locate a frequently used resource).
2.4.3 Domain Resources
Information about domain resources such as 3270 users, RJE workstations, CPI-C side information, and logging
levels may be needed anywhere in the network. For this reason, only one definition is required for each such
resource.
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