N020: Cannot find name called or no answer.

Either the XDB Server is not running, or you are trying to log into an XDB Server that does not exist. Access Options and change the server name. See the XDB Server Administration Guide for instructions on configuring the XDB Server. You may need to increase the timeout period on the client. Also check that NetBIOS is loaded and that your NetBIOS settings are compatible between the server and the client.
Restriction: This topic applies to Windows environments only.

Also make sure you are using the same type of NetBIOS (for example IBM to IBM). This also may be related to not having a bridge for NetBIOS. If you are in a WAN environment, you need to have a bridge established to have connectivity to a server on another LAN.