[Sis-ipo] Thin IPoC Magenta Book Proposal

[Kazz, Greg J (313B)]

Dear SIS-IPO,

This email is in response to several ESA RIDs against RED-4 of IP over CCSDS.


The IP over CCSDS (IPoC) document was intended to select among the many possible ways of carrying IP over CCSDS link layers, and establish a NORMATIVE practice for how this was to be done.  There's one key statement in the document (unfortunately in an INFORMATIVE section) that gets at the heart of the profiling activity:



"The recommended CCSDS method of transferring an IP PDU (enumerated in annex A of reference [8]) over a CCSDS space link is to prepend the IP PDU with the CCSDS IPE header and then incorporate the result into the Encapsulation Packet defined in the CCSDS Encapsulation Service (reference [7])."



Why is this important?  Because it unambiguously states that we DO NOT recommend OTHER methods (e.g., IP-over-HDLC-over-bitstream).  That's EXACTLY what a Magenta book that constitutes a prescriptive profile (which is what IPO is) is supposed to do:  to select among the many ALTERNATIVES established by the plethora of CCSDS Blue Books out there and recommend ONE PATH through those books.


However, currently all of the *protocol* information is in other CCSDS blue books. The rational for this was to provide a "one stop shop" for users/implementers. Nevertheless, I propose stripping out all of the duplication and instead use references to existing blue books where appropriate. Doing so will reduce this book to its core purpose which is the key profiling statement above.



This book SELECTS, it RESTRICTS, it STANDARDIZES.  Profiles are the solution to that.  This is the profile for carrying IP datagrams in CCSDS link layers.  In that sense it is an appropriate document.

So here's my recommendation as WG chair:


1)Move all of the profiling statements in the current document to a normative section. The key profiling statement is the one I quoted above. All other profiling statements in the document are in direct support of that one statement.



2) Remove all of the duplicative text (text found in other CCSDS blue books) and replace with references.



3) Move the IPE specification out of Annex A of reference [8] i.e., Space Link Identifiers Blue book and into this IP over CCSDS Magenta book, it's true home. (This also makes sense since the SLS area has determined that the contents of the Space Link Identifiers book should become a CCSDS registry)



4) Review this Thin IPoC book at the CCSDS meeting in London in the IP over CCSDS WG - note: no new material will be introduced in the book than we currently have rather duplicate information will be stripped and only the profiling information will remain. I will send the current and thin document versions to the WG by the end of this week.



5) If consensus is reached at the London meeting, move to publish IP over CCSDS





Towards this goal I have now published a revised Sept15 (dated in the file name) version of IP over CCSDS with the word revision feature turned on, so that you can see the deletions and modifications that I have made. In addition, I created a copy of the resulting document, with all the revisions accepted. It's file name contains the date, Sept 15 and the words "Thin book".



The URL in the CWE under the SIS-IPO public folder under the Fall 2010 meetings is:

http://cwe.ccsds.org/sis/docs/Forms/AllItems.aspx?RootFolder=%2fsis%2fdocs%2fSIS-IPO%2fMeeting%20Materials%2f2010%2fFall&FolderCTID=&View={390C4ADA-A69B-4E52-A0DA-50C48F989C4B}<http://cwe.ccsds.org/sis/docs/Forms/AllItems.aspx?RootFolder=%2fsis%2fdocs%2fSIS-IPO%2fMeeting%20Materials%2f2010%2fFall&FolderCTID=&View=%7b390C4ADA-A69B-4E52-A0DA-50C48F989C4B%7d>



Please review this new version and I would greatly appreciate your comments and updates to the file: 702x1r4working_Sept15_2010_gjk before our meeting in London -by at least Oct 4, 2010.



Best regards and thanks,



Greg

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