Connection failure and controller descriptions

Sometimes an incorrectly configured controller description can cause a connection failure. The problem source could involve the incorrect configuration of the adapter address, source service access point (SSAP), or destination service access point (DSAP) parameters.

For more information about how these parameters influence a successful connection, see LAN device identification. For other causes of a connection failure, see LAN device connection initiation.

The remote system does not connect

If your controller description uses dial mode, it is not unusual for the system to receive message CPA58E0 (Controller not replying) or CPA57EF (Contact not successful). Remote systems or controller descriptions that do not vary on can cause one of these messages to appear.

Your server does not connect

If your controller description uses answer mode, you might receive the message CPI591A (Controller is varied off or not recognized by local system). The following situations can cause this message to appear:

• The connection requested by the remote system does not exist on the local server. The local server searches for this connection (that is indicated by combining the local adapter address, the DSAP, and the SSAP) in all varied on controller descriptions.
• The controller description does not refer to the line description that could answer the call.

Solutions

• On either side of the connection, verify that the controller description has the correct combination of adapter address, SSAP, and DSAP.
• In the Switched line list field of the controller description, enter the line description that can accept the incoming call. .
• Vary on the correct controller description (use the Work with Configuration Status (WRKCFGSTS) command to vary on the controller).
• Verify that the local and remote adapters are wired into the network correctly.

For information about the relationship between line descriptions and controller descriptions, see Connect LAN devices.