Re: [quicwg/base-drafts] Padding outside QUIC packet (#3333)

ianswett <> Mon, 13 January 2020 14:29 UTC

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Subject: Re: [quicwg/base-drafts] Padding outside QUIC packet (#3333)
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As @ekr pointed out, this type of padding doesn't allow coalescing 0-RTT with the client hello or 0.5RTT server data with the server's first flight, so it limits coalescing in common use cases, though I agree may be easier to implement.

To me, the biggest risk here is that the non-QUIC padding is removed by something on the path.  However, that risk seems similar to the risk that something on the path would split a coalesced packet into two UDP datagrams(discussed in #3317), so it seems acceptable.

Because it prevents coalescing in some useful cases, I don't think it should be recommended, but I can't come up with a strong reason for disallowing it, so I think it should continue to be allowed.

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