[Sis-csi] Re: CCSDS Cislunar Architecture Book CESG RIDs -- RID1

[Jean-Luc.Gerner at esa.int]

Dear Keith,
Your proposal before is not really addressing my concern, that is reinforced
by your statement below:

"Acknowledges that the architecture IS in fact the agreed-to CCSDS
architecture"

This book is a Green Book, in other words an information document. No agency
has endorsed it and it is not the purpose.

The problem comes from the gradual change at CCSDS of the notion of GB. So
far, GBs were developed as a support to a book in the standards track
(generally a Blue Book). For some time now, we see developing GBs as
stand-alone books. Their role and status is undefined. I take these serve to
put together some preliminary material that could possibly be retrieved in
the future once CCSDS undergoes to develop a BB.

That is why I cannot support the terminology "proposed architecture". I
believe my proposal was a reasonable compromise. When it comes to developing
a BB, it could well be that the agencies decide on another architecture. We
must keep this option open.

I hope this can be acceptable to you.

kind regards

Jean-Luc Gerner
TEC-ETN
Tel: +31 71 565 4473


                                                                             
             "Scott, Keith L."                                               
             <kscott at mitre.org>                                              
                                                                          To 
             05/04/2007 18:23           jean-luc.gerner at esa.int              
                                                                          cc 
                                        sis-csi at mailman.ccsds.org, "Durst,   
                                        Robert C." <durst at mitre.org>         
                                                                     Subject 
                                        CCSDS Cislunar Architecture Book     
                                        CESG RIDs -- RID1                    
                                                                             
                                                                             
                                                                             
                                                                             
                                                                             
                                                                             




Jean-Luc,

You proposed changing the title of section 4:

From

"Proposed Architecture"

To

"A Possible Architecture"

on the basis that agencies have not reached consensus as to whether or
not the document represents an agreed way forward for CCSDS.


===========


While I am sensitive to your concern, the Cislunar Working group was
chartered by the CMC to develop this architecture and a suite of
protocol recommendations.  ESA had a hand in approving the WG charter
and was aware of this work even before then.

I would prefer to not change the section title to "A Possible
Architecture," since pretty much ANYTHING could fall under such a
classification.  What if instead this were changed to "Proposed
Architecture for Networked Missions"?

This would accomplish (I hope) two things:
  1) Acknowledges that the architecture IS in fact the agreed-to CCSDS
architecture for missions that use Layer-3 (networked) mechanisms
  2) Allows agencies to bypass the document if Layer-3 mechanisms are
not needed.  That is, agencies could continue with current operations
that use packets as application data units directly over TC/TM and/or
AOS links with the view that these missions do not themselves use
Layer-3 routing.

The 'SCOPE' section (1.4) also already states that the scope of the
document is for "an internetworking communications architecture in the
cislunar mission domain.  It does not prescribe a communications
architecture in general..."


Would making this change address your RID?


        Best Regards,

            --keith



Keith Scott
Chair, CCSDS Cislunar Space Internetworking Working Group
+1.703.983.6547 (voice)
+1.703.983.7142 (Fax)
kscott at mitre.org