Re: [quicwg/base-drafts] unrecoverable loss pattern leads to deadlock (#2863)

Kazuho Oku <notifications@github.com> Fri, 18 October 2019 23:26 UTC

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Date: Fri, 18 Oct 2019 16:26:18 -0700
From: Kazuho Oku <notifications@github.com>
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Subject: Re: [quicwg/base-drafts] unrecoverable loss pattern leads to deadlock (#2863)
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@ekr
> Why not simply prohibit migration until all handshake packets have been ACKed. There is no ambiguity here, as the server is forbidden from initiating migration.

The problem here is that even in the case where an endpoint (e.g., server) has received all the handshake transcript and also the ACKs for all the ack-eliciting Handshake packets it has sent, the other side (e.g., client) might have still some data outstanding (due to ACKs being lost).

@ianswett
> I'd suggest we add a paragraph to section 5.5(https://tools.ietf.org/html/draft-ietf-quic-recovery-23#section-5.5) like:
> "When the handshake has been confirmed, all data sent in Handshake packet is known to be delivered and all recovery state should be discarded."

It's not only the the receive-side state of the Handshake packets that you need to retain forever, but also the state related to that path (e.g., socket). I am not sure we'd prefer that.

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