Re: [quicwg/base-drafts] max_packet_size in 0-RTT (#3447)

Kazuho Oku <> Fri, 21 February 2020 00:20 UTC

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From: Kazuho Oku <>
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Subject: Re: [quicwg/base-drafts] max_packet_size in 0-RTT (#3447)
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> While I don't have a strong opinion on this, I think I'd prefer to just close this with no action, or at most an editorial change, thus forcing clients to remember the value. Freeing the client is not a lot of value add for protocol churn at this stage.

I think the counter argument would be that it does not cause churn, because clients that are willing to remember the value can.

Also, assuming that we agree that "max_packet_size" was in fact "max_udp_payload_size" (as we've been discussing in #3473), I'd point out that applying the "max_udp_payload_size" of the previous connection is going to be pretty complex. A client should not be sending a coalesced datagram that is greater than "max_udp_payload_size" until it learns that peer's maximum for the current connection. Therefore, a client would be having different limits on the packet size depending of if it is generating a coalesced packet.

I am not sure if we should design our protocol based on such a complex (and IMO fragile) design.

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