Re: [Ecn-in-quic] ECN in QUIC update and questions

["Roni Even (A)" <[e-mail]>]

Hi Ingemar,
This is also my understanding and we should clarify this in the document and have some text in the recovery draft referenced by the ECN draft.
I assume that we can recommend at the moment ECT(0) and make ECT(1) optional  saying that it will require a different congestion algorithm (referencing the ECN experiment section 4.2)
Roni

From: Ecn-in-quic [mailto:[e-mail]] On Behalf Of Ingemar Johansson S
Sent: Monday, January 08, 2018 2:32 PM
To: Roni Even (A); [e-mail]
Cc: De Schepper, Koen (Nokia - BE/Antwerp)
Subject: Re: [Ecn-in-quic] ECN in QUIC update and questions

Hi

As regards to the handling of ECT(0) I would say that https://tools.ietf.org/html/draft-ietf-tcpm-alternativebackoff-ecn-05 provides input.
We can probably specify the response for ECT(0) based CE marking (classic) in the recovery draft as a new section
4.7.7 On CE

ECT(1) handling is still a bit open, it should be scalable, similar to DCTCP but it does not exclude other congestion control algorithms, this is work in progress. I believe though that it is still a bit too early to specify the congestion control algorithm for ECT(1).

/Ingemar


From: Roni Even (A) [mailto:[e-mail]]
Sent: den 8 januari 2018 13:21
To: Ingemar Johansson S <[e-mail]<mailto:[e-mail]>>; [e-mail]<mailto:[e-mail]>
Cc: De Schepper, Koen (Nokia - BE/Antwerp) <[e-mail]<mailto:[e-mail]>>
Subject: RE: ECN in QUIC update and questions

Hi,

My understanding from ECN experiments draft  "It is essential that any such change in ECN congestion marking behavior be counterbalanced by use of a different IETF-approved congestion response to CE marks at the sender"

is that there must be different congestion response for ECT(0) and ECT(1) and it is not specified in ECN experiments draft.

So currently we will not have consistent congestion handling for the two ECT until we specify the congestion handling in QUIC or have some reference.

Roni

From: Ingemar Johansson S [mailto:[e-mail]]
Sent: Monday, January 08, 2018 1:30 PM
To: Roni Even (A); [e-mail]<mailto:[e-mail]>
Cc: De Schepper, Koen (Nokia - BE/Antwerp)
Subject: RE: ECN in QUIC update and questions

Hi

Thanks, I corrected the bytes-packet error. The document will not talk about congestion handling in this version, this is left was a later exercise and the intention is that ECT(0) and ECT(1) should be handled as per the recommendations in the  ECN experiments draft (soon RFC). The use of ECT(0) or ECT(1) will be a sender decision as the congestion control is on the sender side.

/Ingemar


From: Roni Even (A) [mailto:[e-mail]]
Sent: den 8 januari 2018 12:23
To: Ingemar Johansson S <[e-mail]<mailto:[e-mail]>>; [e-mail]<mailto:[e-mail]>
Cc: De Schepper, Koen (Nokia - BE/Antwerp) <[e-mail]<mailto:[e-mail]>>
Subject: RE: ECN in QUIC update and questions

Hi,

I noticed that there are still places where bytes are used instead of packets "sufficient with a report of accumulated number of bytes " and "number of ECT marked bytes(or packets) ".

Are you going to say something about when to use ECT(0) and when ECT(1). Is this a sender decision and how is it made?

I understand that the document will not talk about congestion handling, so is a different congestion handling for ECT(0) and ECT(1) will be discussed in the QUIC recovery draft or do we need another document?

Roni Even

From: Ecn-in-quic [mailto:[e-mail]] On Behalf Of Ingemar Johansson S
Sent: Monday, January 08, 2018 11:53 AM
To: [e-mail]<mailto:[e-mail]>
Cc: Ingemar Johansson S; De Schepper, Koen (Nokia - BE/Antwerp)
Subject: [Ecn-in-quic] ECN in QUIC update and questions

Hi

Hope that you have started the new year with lots of new energy.
We (me and Koen) have updated https://github.com/quicwg/base-drafts/wiki/ECN-in-QUIC . The main changes are that a lot of superfluous text is removed, for instance there is now only 1 alternative for the ACK+ECN frame. In addition all the extra text that discussed the timestamps is now gone. The ECN capability check is also clarified. Furthermore it is made possible to set ECT also after the ECN capability check.

There are some questions

  1.  I have added some text that outlines how the overhead can be reduced, this text is somewhat speculative and needs more details to qualify as specification text. Should we have this text in the first draft version or do you prefer that it is removed ?.
  2.  Given that this work is presented at the interim, is it necessary to write up a draft or is it sufficient to present the wiki ?


/Ingemar

==================================
Ingemar Johansson  M.Sc.
Master Researcher

Ericsson Research
Network Protocols & E2E Performance
Labratoriegränd 11
971 28, Luleå, Sweden
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SMS/MMS [phone]
[e-mail]<mailto:[e-mail]>
www.ericsson.com

The world is full of magical things patiently
    waiting for our wits to grow sharper
               Bertrand Russell
==================================