Administration Guide

Chapter 5. Defining Connectivity Components

In order for the CS/AIX 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 CS/AIX, see Defining DLCs, Ports, and Connection Networks.

To configure a link, you need to define a port as described in Defining DLCs, Ports, and Connection Networks. In addition (in most cases), you must configure a link station as described in Defining Link Stations. If LUs on the local node are to communicate with a host using DLUR, you must also define a DLUR PU on the local node as described in 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 or LUA

If you are going to use 3270 or 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 CS/AIX node, so consult your SNA network planner.

Using CPI-C, 5250, or APPC

If you are going to use CPI-C, 5250, 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 CS/AIX node, so you may need to consult your SNA network planner.

Note:

If you are using only AnyNet APPC over IP to access a particular adjacent node, you do not need to configure a link for independent traffic.

Operating as an APPN Node

If the CS/AIX 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 5250 and independent APPC, but they do not apply to 3270 or 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 or LUA on Multiple Nodes

If you are going to use 3270 or LUA on multiple nodes, you can reduce the number of host links required by using SNA gateway. You can use SNA gateway to connect non-CS/AIX nodes. If you want to use SNA gateway, you need to configure a host link, enable SNA gateway, and configure links between the CS/AIX node and the downstream systems. Traffic between the host and downstream LUs can then use links to the SNA gateway 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 SNA gateway.

For information about configuring SNA gateway, see Configuring SNA Gateway.

Using LU 0

If you are configuring LU 0 primary, configure an LU 0 primary line as described in Configuring an LU 0 Primary Line. LU 0 primary is supported only on SDLC links using EIA-232D or EIA-422A adapters.

If you are configuring LU 0 secondary, you can use a port and link station of any DLC type.