[Css-csts] Action Item #02-0511S: Annex E with simplified service state tables

Mon Aug 29 16:33:50 EDT 2011

Martin,

Please see my responses below, in red.

John

From: Martin Karch [mailto:martin.karch at vega.de] 
Sent: Friday, August 26, 2011 8:35 AM
To: John Pietras
Cc: css-csts at mailman.ccsds.org; 'Margherita.di.Giulio at esa.int';
Yves.Doat at esa.int
Subject: RE: [Css-csts] Action Item #02-0511S: Annex E with simplified
service state tables

Dear John,

Please find attached a PDF file of Annex of the Book, which Yves
prepared according to your input "SimplifiedStatefulAnnexE.zip" and
according to the following comments to 921x1r2[Draft
201012]-Annex_E-clean.pdf:

-          In Table E-2 there is the event 'abort-causing event xxx',
but this one is not available in the state table E-1. In Table E-1
position 2 there is 'abortable event xxx'. Perhaps this one needs to be
exchanged with 'abort-causing event xxx'.

Agreed. I had actually hand-marked that inconsistency to be fixed in my
hardcopy, but I obviously didn't do it.

-          In Table E-1 position 1: we feel that in the cell for State 2
there is a {cleanup} missing. If a BIND invocation is received in the
state 'bound' there might be some returns pending, and/or some parameter
values might have changed already. Therefore we feel that also in this
case a {cleanup} is needed after the PeerAbort.

Agreed.

-          Table E-2: The event 'not-authenticated PDU' was removed from
the Access Control Procedure State Tables (in Berlin).  A reference to
'invalid PDU' should also not be made because we agreed to remove
'invalid PDU' from all the state tables. Therefor we think we do not
need the entry in table E-2, and then also not in E-1.

I remember that we agreed to remove this incoming event from the Access
Control procedure state table, and someone came up with some clever
words that specified the handling of authentication failures without
reference to the Access Control (or any other) procedure. However, since
annex E deals with  the state tables for the services themselves, it
might still be appropriate to identify non-authentication of a PDU as a
service-level incoming event. Could you please send me the text for
section 3.2 (updated to include the new wording that was agreed in
Berlin) so that I can see if I agree that it's okay to delete this
incoming event from the service state tables? Thanks.

-           Table E-5: The same problem as describe above with the
'abortable event xxx'/'abort-causing event xxx' exists in Tables E-5 and
E-6.

Agreed.

-          Table E-5: Also here we feel that the 'not authenticated PDU'
is not needed here.

See response above.

-          The Predicate Description Table and Compound Definitions
Table are missing on page E-6.

In E3.8, I stated that tables E-2 (Event Description References), E-3
(Predicate Description Table) and E-4 (Compound Definitions Table) were
also applicable to the stateful state machine case, in order to not
repeat the tables. Actually, I made a slight mistake - I should have
only referenced tables E-3 and E-4, since E-6 replaces E-4 for the Event
Description References. In any case, I can see how this cross reference
is perhaps too subtle, and just explicitly repeating the Predicate
Description and Compound Definitions tables may be easier for the
reader. However, if the new tables E-7 and E-8 are kept, then paragraph
E3.8 should be changed to read "Each CSTS that has a stateful prime
procedure instance shall conform to the state table for a CSTS with
stateful prime procedure instance defined in table E-5, supported by
information in tables E-6 through E-8."  

Best regards,

Martin

From: css-csts-bounces at mailman.ccsds.org
[mailto:css-csts-bounces at mailman.ccsds.org] On Behalf Of John Pietras
Sent: 01 June 2011 20:47
To: css-csts at mailman.ccsds.org
Subject: [Css-csts] Action Item #02-0511S: Annex E with simplified
service state tables

CSTSWG colleagues ---

At the Berlin meeting, I was assigned action item #02-0511S: "JP to
provide the revised version of Annex E, describing the approach for
flagging the active state of started and acknowledged Prime Procedure to
the Association Control Procedure."

 Actually, this action item is slightly misstated. In response to action
item #06-1010F, I had devised an approach that eliminated the need to
distinguish between state machines of CSTSes with stateful prime
procedure instances that are stateful because they employ START and STOP
operations vs. being stateful because they use a three-phased
(acknowledged) operation.  The technical note describing that approach
explained the changes needed in the state tables for the Association
Control procedure and the stateful procedures in the CSTSFW. The
technical note also identified the changes in the state tables of Annex
E (Service State Tables) but did not identify all changes in Annex E
(that is, the changes in the text of Annex E). Action item 02-0511S was
to provide the complete update to Annex E.

The resulting update to Annex E has been uploaded to the CCSDS CSTSWG
CWE Red-1 Framework Review May.2011 folder at URL

http://cwe.ccsds.org/css/docs/CSS-CSTS/CWE%20Private/CSTS%20Framework%20
and%20Concept/Red-1%20Framework%20Review%20May.2011/SimplifiedStatefulAn
nexE.zip

The zip file contains two documents. The Word document "921x1r2[Draft
201012]-stateful-110601.doc" is a marked-up version of the December 2010
Red book with Annex E updated. The PDF file "921x1r2[Draft
201012]-Annex_E-clean.pdf" is a final printing of Annex E with all
changes accepted.

I believe that the revised Annex E is complete, with one exception: the
state tables for the stateless and stateful services use the incoming
event 'not authenticated PDU', the reference for which is given as
section 3.2.3.6. I believe that the definition of this event and the
composition of 3.2.3.6 may have been altered based on our discussions of
valid/invalid PDUs and how and when they are detected. The final
agreed-to rewording of those sections need to be examined and the
reference of the 'not authenticated PDU' incoming events adjusted
accordingly. In any case, the reference to that event needs to be made
more complete - currently it just displays "a)".

Best regards,

John

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