VTAM® extends support for dependent (non-LU 6.2) LUs to APPN networks and combined subarea and APPN networks. Dependent LUs are owned by VTAM and rely on the SSCP to start sessions. There are SSCP-PU and SSCP-LU sessions for dependent LUs. Dependent LUs can start a session when the primary LU supports SLU-initiated sessions (for example, as does a VTAM application program). Dependent LUs can be the secondary LU in sessions with VTAM application programs in APPN, subarea, and combined APPN and subarea networks.