An external communication adapter major node defines a connection (port) between VTAM® and a token-bus network, a token-ring network, a CSMA/CD 802.3 LAN, or an FDDI LAN attached through the IBM® 3172 Nways interconnect controller or an IBM Open Systems Adapter. The minor nodes are the line groups, lines, and physical units attached to the port.
The XCA major node is also used to define a connection (port) between VTAM and an asynchronous transfer mode (ATM) network attached through an IBM S/390® Open Systems Adapter. In addition, the XCA major node is used to define a connection (port) between VTAM and an Enterprise Extender (EE) network.