HP-UX SNAplus2 R7 Administration Guide

Defining Connectivity Components
5Defining Connectivity Components
In order for the SNAplus2 node to communicate with other nodes, you must configure connectivity with at least
one adjacent node. A connecting link can be configured to carry dependent traffic, independent traffic, or both.
You can have adapter cards for one or more link protocols installed in your computer. Much of the information
you need to enter to configure connectivity depends on the link protocol you are using. The remote node must
also have an adapter card of the same type you choose, or there must be a bridge or router between the local and
remote nodes. For a list of the link protocols supported by SNAplus2, see Section 5.1,
Defining DLCs, Ports, and
Connection Networks.
To configure a link, you need to define a port as described in Section 5.1, Defining DLCs, Ports, and Connection
Networks. In addition (in most cases), you must configure a link station as described in Section 5.2, Defining Link
Stations. If LUs on the local node are to communicate with a host using DLUR, you must also de
fine a DLUR PU
on the local node as described in Section 5.3, Defining DLUR PUs.
When using the Motif administration program, a data link control (DLC) is automatically configured as part of the
configuration for the port. In addition, you have the option of defining the port as part of a connection network.
When using command-line configuration, this configuration is separate from port configuration.
The information required for link configuration depends on the link protocol, whether your network is an APPN
network, and on whether the link is for dependent traffic, independent traffic, or both. In addition, the links that
you need to configure depend on what kind of communication you need to support:
Using 3270, RJE or LUA
If you are going to use 3270, RJEor LUA, you need to configure a link to the host computer. The link must be
configured for dependent traffic, and it must be configured on the host computer as well as on the SNAplus2
node, so consult your SNA network planner.
Using CPI-C or APPC
If you are going to use CPI-C or APPC and your network is not an APPN network, you need to configure
links to all the adjacent nodes that you want to access. These links must be configured for independent traffic,
and they must be configured on the adjacent nodes as well as on the SNAplus2 node, so you may need to
consult your SNA network planner.
Operating as an APPN Node
If the SNAplus2 node is an end node or network node in an APPN network, the number of links that you
need to configure can be greatly reduced. You can configure links to one or more adjacent network nodes and
access all nodes in the APPN network using these links. If you want to access other adjacent nodes directly,
you can configure links to them too—this is not usually necessary, but it can give better performance. If the
adjacent nodes are connected by token ring, Ethernet, FDDI, or IP, direct links can be set up dynamically so
you don’t need to configure them—just make sure that you configure the network as a connection network
when you define the port.
The benefits of APPN networking are always available for and independent APPC, but they do not apply to
3270, RJEor LUA unless you use DLUR. (DLUR supports communications between a host and dependent
LUs on the local node or on downstream nodes in an APPN network.) You can use DLUR only if your host
supports DLUS, so you should consult your SNA network planner if you are interested in using DLUR.
Using 3270, RJE or LUA on Multiple Nodes
If you are going to use 3270, RJEor LUA on multiple nodes, you can reduce the number of host links required
by using PU concentration. You can use PU concentration to connect non-SNAplus2 nodes, or SNAplus2
nodes in a different domain. If you want to use PU concentration, you need to configure a host link, enable
PU concentration, and configure links between the SNAplus2 node and the downstream systems. Traffic
between the host and downstream LUs can then use links to the PU concentration instead of requiring direct
links to the host. Unless you already have links between each downstream node and the host, you can avoid
additional investments in cabling and link configuration by using PU concentration.
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