Before a session is established, both session partners must agree on a common set of session parameters. They do this by specifying a logon mode name that identifies a particular set of session parameters. Within an SNA network, both session partners use the same logon mode name, thus ensuring that the correct session parameters are used. When you connect independent SNA networks, however, a given set of session parameters might be known by different names in different networks. Also, a given name might see different session parameters in each network. The alias name translation facility can be used to map a logon mode name in one network to another name in the destination network that provides equivalent session parameters. This translation can occur in any SSCP on the setup path, after the network identifier of the destination network is determined.

As usual, the logon mode name that is used to establish a session must exist in the logon mode table of the secondary logical unit SSCP.