[Css-csts] Proper response to invalid procedure-instance-identifier

[John Pietras]

Members of the CSTSWG ---

In revising the EXECUTE-DIRECTIVE operation definition, I came across a
statement of a question for which I have not been able to find an answer
in the current CSTS documentation. Perhaps I'm just not looking in the
proper place, or the answer seems obvious (but it is not obvious to me).

The question is, what is the proper response to an unrecognized/invalid
procedure-instance-identifier? It is possible for the Provider to
receive an invocation with an invalid value for the
procedure-instance-identifier parameter. 

Should the response of the Provider be to:
a. Ignore the invocation in which the invalid
procedure-instance-identifier appears?;

b. Treat it as an error and return a negative result? If so, should it
be mapped to an existing diagnostic (e.g., 'invalid range'), or should
it get it's own diagnostic ('invalid procedure instance')? If a new
diagnostic, it should be a standard base diagnostic, since the
procedure-instance-identifier parameter is part of the standard
operation headers; 

c. Peer abort? If so, should it be mapped to an existing PEER-ABORT
diagnostic (e.g., 'encoding error') or should it get it's own PEER-ABORT
diagnostic ('invalid procedure instance')? 

It seems that it would be reasonable to peer abort, given that using the
wrong procedure instance identifier would indicate a serious breakdown
in the User's CSTS protocol machine. 

Is there a consensus on which of these responses would apply?

Best regards,
John

John Pietras
Global Science & Technology, Inc. (GST)
7855 Walker Drive
Suite 200
Greenbelt, Maryland, USA
20770-3239
Direct:   +1-240-542-1155
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