Re: New Version Notification for draft-michel-quic-fec-00.txt

[François Michel <[e-mail]>]

Hi Nico,

On 26/10/22 10:04, Nicolas Kuhn wrote:
> Dear François, all,
> 
> Thank you for this document. This is very important for the 
> lossy-GEO-satellite scenario, so thank you!
> 
> I have some questions/comments on the document :
> - Taxonomy : you may want to refer to RFC8406 on the taxonomy related to 
> coding
> - On the coding channel :
>    "A coding channel can be seen as a
>     communication channel between a QUIC receiver and a FEC decoder."
>    => This is in contradiction with the notion proposed in RFC 9265.
>    I think that the coding channel should be seen between the FEC-coder 
> and the FEC-decoder.

True, I should avoid those ambiguities. :-)

> - The notion of APP_DATA in Figure 1 is not clear to me. IMHO the 
> presentation on this should be improved.

I've put APP_DATA to represent any data sent by applications transiting
through streams or datagrams. We sould find a way to make it easy to
understand that the APP_DATA are part of the source symbols.

> - On DATAGRAMS : I agree that if a solution can also protect DATAGRAMS, 
> this could help in lossy scenarios
> - "In this document,
>     we propose to consider whole frames as part of the source symbols."
>    => This is important and should be highlighted in the document. It 
> may be worth expliciting what is meant by "whole frames" and maybe 
> provide examples.
> - Alternative 1 vs Alternative 2 : alternative 2 has an impact on the 
> QUIC packet scheduler. For this reason, I am not sure whether it is 
> relevant.

(+Sam that might be interested as we had similar discussions on another
mail loop)
I also prefer a bit the concepts behind Alternative 1 but it may seem
harder to implement than Alternative 2 and introduces the concept of
wrapped frames that may be puzzling too. I guess time and implementations
may tell us which alternative is the best with running code.

> 
> I hope this helps,

This helps ! Thank you for your comments.

Franz

> Kind regards,
> 
> Nicolas
> 
> On Fri, Oct 21, 2022 at 2:50 PM François Michel 
> <[e-mail] <mailto:[e-mail]>> wrote:
> 
>     Dear all,
> 
>     Here is a draft discussing the addition of Forward Erasure
>     Correction to
>     QUIC.
> 
>     We wrote this draft to discuss FEC in QUIC and experiment with people.
>     It is inspired by our previous work at the nwcrg. We also have
>     interesting real-network results that we would be happy to show to
>     motivate the interest for this extension.
> 
>     The design is at an early stage and is intended to evolve. Do not
>     hesitate to provide us with comments on the document or the
>     extension in
>     general.
> 
>     Regards,
> 
>     François
> 
> 
>     -------- Message transféré --------
>     Sujet : New Version Notification for draft-michel-quic-fec-00.txt
>     Date : Fri, 21 Oct 2022 05:11:22 -0700
>     De : [e-mail] <mailto:[e-mail]>
>     Pour : François Michel <[e-mail]
>     <mailto:[e-mail]>>, Francois Michel
>     <[e-mail]
>     <mailto:[e-mail]>>, Olivier Bonaventure
>     <[e-mail]
>     <mailto:[e-mail]>>, Olivier Bonaventure
>     <[e-mail]
>     <mailto:[e-mail]>>
> 
> 
>     A new version of I-D, draft-michel-quic-fec-00.txt
>     has been successfully submitted by François Michel and posted to the
>     IETF repository.
> 
>     Name:           draft-michel-quic-fec
>     Revision:       00
>     Title:          Forward Erasure Correction for QUIC loss recovery
>     Document date:  2022-10-21
>     Group:          Individual Submission
>     Pages:          14
>     URL: https://www.ietf.org/archive/id/draft-michel-quic-fec-00.txt
>     <https://www.ietf.org/archive/id/draft-michel-quic-fec-00.txt>>     Status: https://datatracker.ietf.org/doc/draft-michel-quic-fec
>     <https://datatracker.ietf.org/doc/draft-michel-quic-fec>>     Html:
>     https://www.ietf.org/archive/id/draft-michel-quic-fec-00.html
>     <https://www.ietf.org/archive/id/draft-michel-quic-fec-00.html>>     Htmlized:
>     https://datatracker.ietf.org/doc/html/draft-michel-quic-fec
>     <https://datatracker.ietf.org/doc/html/draft-michel-quic-fec>> 
>     Abstract:
>          This documents lays down the QUIC protocol design considerations
>          needed for QUIC to apply Forward Erasure Correction on the data
>     sent
>          through the network.
> 
> 
> 
> 
>     The IETF Secretariat
> 
>