[CESG] CESG-P-2020-12-004 Approval to publish CCSDS 766.1-B-3, Digital Motion Imagery (Blue Book, Issue 3)

Thu Mar 11 17:45:50 UTC 2021

Dear CESG Members,

Conditions for approval of CCSDS 766.1-B-3, Digital Motion Imagery 
(Blue Book, Issue 3) have been disposed to the satisfaction of the 
AD(s) who voted to approve with conditions. The Secretariat will now 
proceed with CMC polling to authorize publication.
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From:	Wilmot, Jonathan J. (GSFC-5800) <jonathan.j.wilmot at nasa.gov>
Sent:	Thursday, March 11, 2021 12:16 PM
To:	Grubbs, Rodney P. (MSFC-HP27); Thomas Gannett
Cc:	Burleigh, Scott C (JPL-312B)[JPL Employee]; Lindblom, Walter E. (MSFC-
IS40)[NICS]
Subject:	RE: [EXTERNAL] RE: Conditions/Comments related to approval to publish 
766.1-B-3

Categories:	Poll Condition Closure

Rodney,

   Thanks. Consider the condition closed.

And yes Tom, you were correct in that this was not closed.

   Kind regards,

         Jonathan

Jonathan Wilmot
NASA/GSFC 
Code 580 Senior Engineer for Flight Systems
cFS Software Architect
CCSDS SOIS Area Director
Office 301-286-2623
Cell 301-751-2658

From: Grubbs, Rodney P. (MSFC-HP27) <rodney.grubbs at nasa.gov>  
Sent: Thursday, March 11, 2021 12:07 PM 
To: Thomas Gannett <thomas.gannett at tgannett.net>; Wilmot, Jonathan J. (GSFC-5800) 
<jonathan.j.wilmot at nasa.gov> 
Cc: Burleigh, Scott C (JPL-312B)[JPL Employee] <scott.c.burleigh at jpl.nasa.gov>; Lindblom, Walter E. 
(MSFC-IS40)[NICS] <walt.lindblom at nasa.gov> 
Subject: Re: [EXTERNAL] RE: Conditions/Comments related to approval to publish 766.1-B-3

Yes, we agreed with the changed wording. I think the trail broke when I asked Walt to get with you 
about all the changes, versioning, etc. I failed to notify you (Tom) directly. So as usual, its the damn 
working group Chairmans fault!

Jonathan, with this, do you agree your conditions are closed?

Rodney Grubbs
NASA Imagery Experts Program Manager
256-603-3270

From: Thomas Gannett <thomas.gannett at tgannett.net> 
Date: Thursday, March 11, 2021 at 11:03 AM 
To: "Wilmot, Jonathan J. (GSFC-5800)" <jonathan.j.wilmot at nasa.gov>, Rodney Grubbs 
<rodney.grubbs at nasa.gov> 
Cc: "Burleigh, Scott C (JPL-312B)[JPL Employee]" <scott.c.burleigh at jpl.nasa.gov>, "Lindblom, 
Walter E. (MSFC-IS40)[NICS]" <walt.lindblom at nasa.gov> 
Subject: [EXTERNAL] RE: Conditions/Comments related to approval to publish 766.1-B-3

Jonathan, Rodney:

If the loop was closed on the last requested change, I did not see it. I need an email chain showing 
Rodney agrees with the changed wording and that Jonathan agrees his conditions are closed.

(Sorry to be so nit-picky, but as Erik pointed out, we have disputative ADs watching all this stuff.)

Tom

Logothete, L.L.C.
thomas.gannett at tgannett.net
+1 443 472 0805

From: Wilmot, Jonathan J. (GSFC-5800) [mailto:jonathan.j.wilmot at nasa.gov]  
Sent: Thursday, January 28, 2021 12:13 PM 
To: Grubbs, Rodney P. (MSFC-HP27) 
Cc: Burleigh, Scott C (JPL-312B)[JPL Employee]; Thomas Gannett; Lindblom, Walter E. (MSFC-
IS40)[NICS] 
Subject: RE: Conditions/Comments related to approval to publish 766.1-B-3

Rodney,

   For 3.6.2.4, I would still like to see Note - RTP-based decoders need to have sufficient buffering to 
manage out-of-order arrival., to something like

Note - RTP-based decoders need to be aware of, and manage out-of-order arrival.

With my implementation hat on, it is not feasible to have RTP buffers that hold hours of outof-order 
RTP packets over DTN. In reality, I expect they would just skip that packet and continue functioning. RTP 
decoders already handle packet loss.

   Kind regards,

         Jonathan

Jonathan Wilmot
NASA/GSFC 
Code 580 Senior Engineer for Flight Systems
cFS Software Architect
CCSDS SOIS Area Director
Office 301-286-2623
Cell 301-751-2658

From: Grubbs, Rodney P. (MSFC-HP27) <rodney.grubbs at nasa.gov>  
Sent: Thursday, January 28, 2021 11:21 AM 
To: Wilmot, Jonathan J. (GSFC-5800) <jonathan.j.wilmot at nasa.gov> 
Cc: Burleigh, Scott C (JPL-312B)[JPL Employee] <scott.c.burleigh at jpl.nasa.gov>; Thomas Gannett 
<thomas.gannett at tgannett.net>; Lindblom, Walter E. (MSFC-IS40)[NICS] <walt.lindblom at nasa.gov> 
Subject: Conditions/Comments related to approval to publish 766.1-B-3

Jonathan, please see below related to your conditions/comments and confirm they resolve your 
concerns:

1) Concern that 
    section 3.6.2.3  references CCSDS 766.3-R-1 specification for RTP as 
    Transport for Audio and Video over DTN and the red book is not 
    available to the reader.

Response: after discussion with Tom, he recommends the following:

So 3.6.2.3 should read:

3.6.2.3   RTP data conveyed over Bundle Protocol networks must be compliant with reference 
[n] the CCSDS 766.3-R-1 Specification for RTP as Transport for Audio and Video over DTN.

Where [n] is a new normative reference,

[n] Specification for RTP as Transport for Audio and Video over DTN. Issue 1. Recommendation for Space 
Data System Standards (Blue Book), CCSDS 766.3-B-1. Forthcoming.

2) The statement in 3.6.2.4 that "RTP-based decoders must have 
sufficient buffering to manage out-of-order arrival" would be very 
difficult to bound as the needed bundle may come at the next contact 
if it took a different path. Suggest that 3.6.2.4 reference 766.3 and 
state that RTP decoder buffer size is related to bundle TTL and 
should be tolerant of packet loss and/or use DTPC as described in 766.3

Response: Again, after discussing with Tom, he recommends the following:

For 3.6.2.4, I can change it to the following note:

Note - RTP-based decoders need to have sufficient buffering to manage out-of-order arrival.

3) 3.7.2.2.2 CFDP class 2 should be stated as an option for reliable 
    transmission where a eliable UT layer is not available.

Response: I deferred this one to Scott Burleigh. I understand hes discussed this with you and there is 
agreement to remove the words transfer over a reliable UT layer from the line on Class 1 in 3.7.2.2.1

Rodney Grubbs
NASA Imagery Experts Program Manager
256-603-3270