A VTAM® subarea node is an SNA type 5 node that functions in a hierarchical environment. Subarea nodes provide services for and control over peripheral nodes. Peripheral nodes require the services of a VTAM subarea node to communicate with other peripheral nodes and subarea nodes in the network. Peripheral nodes include SNA type 2.1, 2.0 or type 1 nodes and function as distributed processors, cluster controllers, or workstations. Type 2.1 nodes can use low-entry networking (LEN) or Advanced Peer-to-Peer Networking (APPN) connections to communicate with adjacent type 2.1 nodes; however, when attaching to a VTAM subarea node, they are restricted to using LEN connections.