Interfaces and interactions

The two sessions that the application program must initiate with ISTPDCLU use the following LU-LU session type 0 protocols:

The user's application program initiates the sessions and acts as the primary logical unit.
No error recovery exists for the sessions.
The user's application program must restart any failed session.
The user's application program only receives data over the sessions; it might never send data.
The ISTPDCLU application program sends data to the user's application program.
No responses are requested from the primary logical unit.
The session uses function management profile 2 and transmission profile 3.

The session parameter contained in the BIND must specify the following:

No brackets and no chaining of RUs are permitted.
Inbound data to the user's application program is paced.
No responses are requested from the primary session end.
The secondary session end runs in delayed request mode.
Normal flow is specified.
No compression is allowed.
Data flow control RUs are not allowed.
There are no function management headers.
The SEND/RECEIVE mode is full-duplex.
The LU type is 0.
Cryptography is not supported for the session.
Negotiable BIND is not supported.

When the trace data session is bound, the BIND user data area must contain the EBCDIC characters TRACE. When the session-awareness data session is bound, the BIND must contain the EBCDIC characters SESSA. The ISTPDCLU application program's SCIP exit routine ensures a session limit of two and rejects any BIND requests after the limit is exceeded.