Subject: [Ecn-in-quic] Pull request for adding ECN in QUIC

From: Magnus Westerlund <[email-masked]>
Date: Tue, 22 May 2018 20:35:30 +0200

Design Team

I have produced a pull request based on our proposal for how to add ECN 
support in QUIC. It is based on the Wiki content, but I have written 
quite some glue and other changes. I like to send this out to the WG 
later the week. As it is in github the active contributors may start 
comment on it immediately. So please review and comment.

https://github.com/quicwg/base-drafts/pull/1372

There is one part in the transport draft that I don't think quite work, 
and that is Section 6.9.4.2.

    In the sub-sequent ACK or ACK_ECN received, the endpoint needs to
    track which packets that are acknowledged.  Only packets sent after
    connection migration are included in the number of ACKed packets and
    compared to the difference in the ECN counters received in the ACK
    compared to the locally stored state.

The issue I have is that this is not robust against cases where you 
might have acking of packets from prior to the connection migration 
point. Thus counting can be corrupted. Help apreciated.

Also the recovery part needs more than pseudo code, and that hasn't been 
written yet.

Cheers

Magnus Westerlund

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