[Sis-dtn] [EXTERNAL] Re: [EXT] RE: LTP vs LTPv2
Vint Cerf
vint at google.com
Mon Oct 11 14:18:00 UTC 2021
i think Keith and Leigh have correctly characterized the situation. I would
stick with both as valid but incompatible. CF: IPv4 and IPv6'
v
On Mon, Oct 11, 2021 at 10:12 AM Dr. Keith L Scott <kscott at mitre.org> wrote:
> Peter,
>
>
>
> I think the real issue at hand is whether or not to maintain the LTPv1
> spec as Blue once LTPv2 is published.
>
>
>
> My interpretation of Leigh’s argument is that vendors are currently
> implementing to LTPv1 (and the current BPv6-based BP for CCSDS Book) and
> that deprecating those specs in favor of new, non-backward-compatible ones
> would be looked upon unfavorably.
>
>
>
> v/r,
>
>
>
> --keith
>
>
>
> *From: *Tomaso.deCola at dlr.de <Tomaso.deCola at dlr.de>
> *Date: *Monday, October 11, 2021 at 3:11 AM
> *To: *peter.m.shames at jpl.nasa.gov <peter.m.shames at jpl.nasa.gov>
> *Cc: *Dr. Keith L Scott <kscott at mitre.org>, Gifford, Kevin <
> kevin.gifford at colorado.edu>, marc.sanchez.net at jpl.nasa.gov <
> marc.sanchez.net at jpl.nasa.gov>, sis-dtn at mailman.ccsds.org <
> sis-dtn at mailman.ccsds.org>
> *Subject: *RE: [EXTERNAL] Re: [EXT] RE: LTP vs LTPv2
>
> Dear Peter,
>
>
>
> Thank you for your kind support and availability for helping us in finding
> a suitable solution.
>
> Indeed the two options you have mentioned are also those we have put on
> the table as possible solutions, although both of them show pros and cons
> and therefore compromise and agreement/consensus between the parties will
> have to be reached. This discussion will keep on going during the next DTN
> telco as well as the official CCSDS DTN WG Fall meetings in order to reach
> soon an agreed approach as also mentioned by Keith in a previous e-mail. In
> case no solution will be agreed, then I’ll certainly bring this point in
> the SIS area summary at the CESG meeting in November in order to find a way
> out for this impasse. Obviously, I’ll certainly count on your and other
> CESG colleagues suggestions to move forward and more importantly to avoid
> any postponed decision that would be detrimental to the activities of the
> DTN WG.
>
>
>
> Best Regards
>
> Tomaso
>
>
>
>
>
> *From:* Shames, Peter M (US 312B) <peter.m.shames at jpl.nasa.gov>
> *Sent:* Samstag, 9. Oktober 2021 01:26
> *To:* Kevin K Gifford <kevin.gifford at colorado.edu>; Dr. Keith L Scott <
> kscott at mitre.org>; Cola, Tomaso de <Tomaso.deCola at dlr.de>; Sanchez Net,
> Marc (US 332H) <marc.sanchez.net at jpl.nasa.gov>
> *Cc:* sis-dtn at mailman.ccsds.org
> *Subject:* Re: [EXTERNAL] Re: [EXT] RE: LTP vs LTPv2
>
>
>
> Guys,
>
>
>
> As a long term member of the CESG I do agree that you can kick it
> “upstairs” to the CESG and have, I believe, a hope of getting a sensible
> response (most of the time). Heck, we are human and therefore fallible.
>
>
>
> From my own point of view I recommend doing two things:
>
>
>
> 1. As I understand it, they are different protocols, hence not
> “backward compatible”. Using the “version” option, including, in this
> case, adopting some explicit name extension like LTPv2 makes the most sense
> to me. The rationale for that is that what you plan to produce is not
> backward compatible with v1. In other words, there is no way to configure
> V2, without the new options, and still have a v1 implementation accept it.
> 2. Silverize the v1 book. This is normally done when a new protocol
> version is created. The old silver book will still be available and it may
> be referenced with its (new) silver name and number. This has happened
> before with other specs. It is not unusual for some mission to nail their
> interface to some specific version of a document, even, in some cases, a
> Red Book (which is really dangerous since they are likely to change).
>
>
>
> If you want to discuss this further please let me know. And it you do
> decide to send it to the CESG you now know where I stand, and why. Of
> course, if any of my assumptions are flawed I am happy to be corrected.
>
>
>
> Cheers, Peter
>
>
>
>
>
> *From: *Kevin K Gifford <kevin.gifford at colorado.edu>
> *Date: *Friday, October 8, 2021 at 11:58 AM
> *To: *Keith Scott <kscott at mitre.org>, "Tomaso.deCola at dlr.de" <
> Tomaso.deCola at dlr.de>, Marc Sanchez Net <marc.sanchez.net at jpl.nasa.gov>
> *Cc: *"sis-dtn at mailman.ccsds.org" <sis-dtn at mailman.ccsds.org>, Peter
> Shames <peter.m.shames at jpl.nasa.gov>, Kevin K Gifford <
> kevin.gifford at colorado.edu>
> *Subject: *[EXTERNAL] Re: [EXT] RE: LTP vs LTPv2
>
>
>
> Hi SIS-DTN -
>
>
>
> FWIW, I want to emphasize that the CESG does a great job in this regard
> (fixing issues that arise in WGs or inter-WG conflicts or inter-agency
> conflicts).
>
> -- Keith was a member of the CESG for several years and understands this
> vital role that the CESG plays in issues such as this
>
>
>
> Thus, my *two cents worth* is await CESG advice as well as Keith already
> stated (I wanted to maybe ease any queasiness in regard to CESG
> involvement/inputs).
>
>
>
> Thanks.
>
>
>
> Kevin
> ------------------------------
>
> *From:* SIS-DTN <sis-dtn-bounces at mailman.ccsds.org> on behalf of Dr.
> Keith L Scott <kscott at mitre.org>
> *Sent:* Friday, October 8, 2021 12:49 PM
> *To:* Tomaso.deCola at dlr.de <Tomaso.deCola at dlr.de>;
> marc.sanchez.net at jpl.nasa.gov <marc.sanchez.net at jpl.nasa.gov>
> *Cc:* sis-dtn at mailman.ccsds.org <sis-dtn at mailman.ccsds.org>
> *Subject:* Re: [Sis-dtn] [EXT] RE: LTP vs LTPv2
>
>
>
> OK fine, if the CESG decides to not rule on it, great, we’ll make a
> decision in the WG and they can live with it (and we can certainly discuss
> it SOME in the WG; don’t want to put too much time into it until the CESG
> is at least given a chance to get us out of this).
>
>
>
> --keith
>
>
>
> *From: *Tomaso.deCola at dlr.de <Tomaso.deCola at dlr.de>
> *Date: *Friday, October 8, 2021 at 10:04 AM
> *To: *Dr. Keith L Scott <kscott at mitre.org>, marc.sanchez.net at jpl.nasa.gov
> <marc.sanchez.net at jpl.nasa.gov>
> *Cc: *sis-dtn at mailman.ccsds.org <sis-dtn at mailman.ccsds.org>
> *Subject: *RE: [EXT] RE: LTP vs LTPv2
>
> Hi Keith,
>
>
>
> I agree with your point on troubles in maintaining two books and the fact
> that this will imply the same treatment for BPv7. Then whether agencies are
> happy to refer to a silver book rather than a blue book is a bit question
> mark in my opinion. I remember we decided a few years ago not to silverize
> SCPS-TP exactly because there were activities or usage of the corresponding
> blue book.
>
> We can certainly bring this matter to the next CESG meeting, although I
> fear that there might be no strict decision in this regard, since I think
> there is no specific rule again either approaches and the hot potato could
> be sent back to WG.
>
>
>
> Regards,
>
>
>
> Tomaso
>
> *From:* Dr. Keith L Scott <kscott at mitre.org>
> *Sent:* Freitag, 8. Oktober 2021 15:52
> *To:* Cola, Tomaso de <Tomaso.deCola at dlr.de>;
> marc.sanchez.net at jpl.nasa.gov
> *Cc:* sis-dtn at mailman.ccsds.org
> *Subject:* Re: [EXT] RE: LTP vs LTPv2
>
>
>
> I don’t like it, but I propose that the WG move forward with developing
> the book and you bring up the new-version vs. new-book issue to the CESG.
>
>
>
> Reasons I don’t like the two-book solution:
>
>
>
> - So now we’re maintaining two versions of LTP, which version are
> folks supposed to choose for missions going forward? They’ll choose the
> one with flight heritage, right?
> - We’ll have to do the same thing with BPv7
> - There’s a version number in the header; receivers will know what was
> sent.
> - The book as Silver is still reference-able. If folks have systems
> they’re building to the current (v1) book, they can switch to referencing
> the silver book.
> - Why don’t we do that with ALL CCSDS books, backward-compatible or
> not?
>
>
>
> --keith
>
>
>
>
>
> *From: *Tomaso.deCola at dlr.de <Tomaso.deCola at dlr.de>
> *Date: *Friday, October 8, 2021 at 4:19 AM
> *To: *marc.sanchez.net at jpl.nasa.gov <marc.sanchez.net at jpl.nasa.gov>, Dr.
> Keith L Scott <kscott at mitre.org>
> *Cc: *sis-dtn at mailman.ccsds.org <sis-dtn at mailman.ccsds.org>
> *Subject: *[EXT] RE: LTP vs LTPv2
>
> Then probably we should better keep two books, one with the “old LTP” for
> which we’ll do some pink sheets to fix some inconsistencies and another one
> (the new LTP). In such a away we could have two versions of LTP available,
> similarly to IPv4 and IPv6 in IETF. Probably we may have to slightly change
> the title of the books (v1 and v2?) to have a clear demarcation between the
> two version of the protocols and avoid any ambiguity.
>
> @Scott, Keith L. <kscott at mitre.org>:what do you think?
>
>
>
> Tomaso
>
>
>
> *From:* SIS-DTN <sis-dtn-bounces at mailman.ccsds.org> *On Behalf Of *Sanchez
> Net, Marc (US 332H) via SIS-DTN
> *Sent:* Donnerstag, 7. Oktober 2021 00:21
> *To:* sis-dtn at mailman.ccsds.org
> *Subject:* [Sis-dtn] LTP vs LTPv2
>
>
>
> All,
>
>
>
> I had to leave today’s meeting early. Did we reach consensus on how to
> proceed?
>
>
>
> Also, I will note that some colleagues at JPL (I have similar concerns) do
> not really like the idea of turning the current version of LTP into a
> silver book. The problem is that, by definition, a silver book implies that
> a protocol is deprecated or obsolete, but several systems that are being
> built today use BPv6+LTP or BPv7+LTP and thus might be in operation for a
> long time. So, essentially, we are “telling” industry that they have
> developed an already obsolete standard?
>
>
>
> Best,
>
>
> -----------------------------------------------------------------------------------------------------------------------
>
> Marc Sanchez Net
>
> Telecommunications Engineer
>
> Jet Propulsion Laboratory
>
> Office: (818) 354-1650 <(818)%20393-5840> | Email:
> marc.sanchez.net at jpl.nasa.gov
>
>
> -----------------------------------------------------------------------------------------------------------------------
>
>
> _______________________________________________
> SIS-DTN mailing list
> SIS-DTN at mailman.ccsds.org
> https://mailman.ccsds.org/cgi-bin/mailman/listinfo/sis-dtn
>
--
Please send any postal/overnight deliveries to:
Vint Cerf
1435 Woodhurst Blvd
McLean, VA 22102
703-448-0965
until further notice
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.ccsds.org/pipermail/sis-dtn/attachments/20211011/6e89c69d/attachment-0001.htm>
More information about the SIS-DTN
mailing list