Re: [quicwg/base-drafts] Stateless Reset Eternal Ping Pong (#1443)

[Martin Thomson <[e-mail]>]

> I'm not trying to ensure a reset is sent in response to an ACK-only packet.

A misunderstanding then...

> I'm suggesting the reset packet attempt to look like an ACK-only packet 

Yes, but I think that you're missing the point that an ACK-only packet for ANY connection is potentially much bigger than an ACK-only packet for THIS connection.

Let's say that your peer chose no connection ID (this would be common for a server that sends a stateless reset).  Then a minimal ACK-only packet is 4 octets of ACK, 2 octets of short header, and 16 octets of authentication tag.  That's 22 octets.  4 octets of ACK is unlikely, but it is a size you might expect to see early in a connection.

Now if you don't know how long the connection ID of your peer is and you want to ensure that the packet you send is plausible, you have to assume that they used the maximum size.  That's 18 octets.  Then add the short header, a PING frame (which is smaller than the ACK), and authentication tag.  That leads to 37 octets - the number in the draft.

While it might be valid to send less than 37 octets, you can't be sure that it always will be.

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