Re: representation of interfaces to the messaging service

[Henry Lowe <hlowe@omg.org>]

Marty,

As a former OSI type, this is the sort of think I was thinking 
of when I mentioned the use of a conceptual interface (I/F). 
However, 
1. you need to add parameters to the primitives (afraid I'd have 
   to look at an old document to see exactly how we used to do it, 
   and 
2. this notation only deals with events which involved a protocol 
   exchange, i.e., it doesn't cover (what we used to call "local") 
   events which don't cause protocol to be sent or result from 
   protocol being received.

Item 2 would have to be dealt with for ebXML, IMHO.  It is usable, 
however, and can be extended to cover local events where necessary.  

Rather than start using the OSI approach (which after all, has its 
origins in the late 1970's), I would support your second suggestion 
of using UML as it's richer (and also being used by the BP folk as 
I understand). 

Best regards,
Henry
------------------------------------------
At 10:21 AM 08/30/2000 -0400, mwsachs@us.ibm.com wrote:
>There is an inter-layer interface representation that some standards use,
>which I have seen referred to as the OSI interface model. It is considered
>to be technology and implementation independent and definitely won't be
>confused with an API. It is expressed in natural language.
>
>Consider a 2-layer structure, TOP and BOTTOM.  The conceptual interface
>between the TOP and BOTTOM is expressed in terms of four primitives:
>
>   Request:  TOP makes a request to BOTTOM for a specified service.
>   Indication:  BOTTOM sends a particular signal to TOP
>   Response:  TOP sends the results of the previous Indication to BOTTOM.
>   Confirm:  BOTTOM conveys the results of one or more service requests to
>   TOP.
>
>The specific request, etc. and the name of the "sending" level are
>concatenated to the primitive name thus: TOP_Data.Request.
>
>Text associated with the primitive specifies the characteristics of the
>primitive, such as when generated, effect on receipt, and status.
>
>Associated with naming the primitive is a brief description of the
>semantics (typically one sentence).
>
>Examples of this are in the ANSI Fibre Channel Physical and Signaling
>Interface specification which I unfortunately have only on paper.
>
>I mention this only to add to the spectrum of choice.  It is highly likely
>that the BP-TRP interface will have to be in UML to mesh with the BP meta
>model. This OSI interface representation is not anywhere as rich as UML but
>it is a compact easily understood representation.  If we use a UML model,
>we will certainly have to add the same kind of explanatory text.
>
>Regards,
>Marty
>
>
>
>****************************************************************************
>*********
>
>Martin W. Sachs
>IBM T. J. Watson Research Center
>P. O. B. 704
>Yorktown Hts, NY 10598
>914-784-7287;  IBM tie line 863-7287
>Notes address:  Martin W Sachs/Watson/IBM
>Internet address:  mwsachs @ us.ibm.com
>****************************************************************************
>*********
>
>