From: [email-masked]
Date: Thu, 3 Mar 94 13:33:35 +0100

During our studies on the implementation of CPI-C 2.0 on an OSI-TP CRM,
we encountered the following problem:

Let's have a half duplex conversation with sync_level CM_SYNC_POINT, using
the X/Open TX interface for resource recovery and commitment.

When the TP issues the CMPREP call, it enters the state Prepared (18) 
(see the HDX state table in appendix C in the CPI-C revised third draft from 
december 15, 1993). According to the mapping tables in appendix D.2.2,
the Prepare is mapped to a TP-PREPARE-REQ and the OSI-TP CRM, after having
sent the primitive, enters a state in which it essentially is waiting for 
the TP-READY-IND.

Let's assume now, the TP issues a CMRCV in this state (which is valid in 
the Prepared state due to the state table) to wait for the outcome of the 
Prepare by checking the status_received parameter, as described in the
usage notes for the Prepare call.

Having received the TP-READY-IND, the entry for the TP-READY-IND in the 
mapping table 48 in appendix D.2.3 reads:
"Handeled by a resource recovery component".

Thus, there is no statement in the CPI-C 2.0 specification on how and when 
the outstanding CMRCV will be completed, returning with status_received set 
to CM_PREPARE_OK to inform the TP about the positive outcome of the Prepare.
On the other hand, this is the only way for the TP to get that information,
see usage notes for the Prepare call.

The TX specification, of course, doesn't provide any mapping information 
either, because that interface is independent of CPI-C.

Now, if this is just an error in the mapping tables in appendix D.2.3, it 
should be fixed.

However, we believe that this rather is a general problem of the CPI-C 2.0
specification, concerning the insufficient description of the interactions 
between CPI-C and the TX interface, and that for this reason some extensions
to the CPI-C 2.0 specification are necessary to clarify that relationship.

    Best regards
    Uwe Goellner

-----------------------------------------------------------------------------
Uwe Goellner                         |   Tel.:  07531-87-4628
Computer Gesellschaft Konstanz mbH   |   Fax:   07531-87-4888
Max-Stromeyer-Strasse 116            |   Email: [email-masked]
78467 Konstanz                       |   NERV:  [email-masked]
Germany                              |
=============================================================================