SNA STSN terminal considerations

ETO terminals that use the SNA STSN function (Finance, SLU-P, and ISC) must provide a user queue name during logon, because this queue is used to resolve the sequence number exchange that is part of the IMS connection process for this type of terminal.

The ways to provide the user name include:

CINIT data sent by the terminal
CINIT data provided using a separate terminal host product, such as VTAM® unsolicited system services
A user Logon exit routine (DFSLGNX0), except for ISC
An IMS command (/OPNDST can specify user name)
Autologon parameters supplied by user descriptors or by the Destination Creation exit routine

The Logon exit routine is the last opportunity to provide the user name. If no user name is provided for ETO STSN terminals, the logon is rejected with an error message. This differs slightly from other terminal types, which allow user signon after the logon has occurred. A signon is required before being able to use the terminal for IMS activity (transactions or commands), so the difference is only in requiring the signon data earlier for STSN terminals. The /SIGN command is supported for STSN terminals.