Figure 1 depicts PLU-initiated session flows for the alias selection function; it indicates when the alias selection function is invoked and for what reason. The numbers correspond to the descriptions after the figure.

1. VTAM® passes the DLU alias name, the OLU real name, and the logon mode name as known in the OLU's network. The alias selection function has the option of returning the DLU real name, the network ID of the DLU real name, the name of the SSCP that owns the DLU, the OLU alias name, and the logon mode name as known in the DLU network.
2. Same description as number 1.
3. VTAM passes the DLU alias name. The alias selection function has the option of returning the DLU real name, the network ID of the DLU real name, and the owning SSCP of the DLU.
4. VTAM requests translations from NETA to NETC for the OLU alias name and the logon mode name. VTAM also requests the name of the SSCP that owns the DLU.
5. Identical to number 3 except no request is made for the owning SSCP.
6. VTAM drives the session management exit routine to translate the COS name from NETC to NETB, and to translate the associated LU names from NETC to NETA.
7. Same description as number 6.
8. VTAM drives the exit routine to translate the COS name from NETB to NETA. No attempt is made to translate the associated LU names because this host has already attempted to translate them.
9. VTAM drives the exit routine to translate the COS name from NETB to NETA, and to translate the associated LU names from NETC to NETA.