Re: [quicwg/base-drafts] Improve ACK_ECN frame encoding (e.g., use bit-vector) (#1439)

[Martin Thomson <[e-mail]>]

I'm not sure that this is simpler.  If we were going this way, maybe it needs a better encoding than bit-stuffing a varint.  Not sure what that looks like though.

You could save a whole bit by making it impossible to send two blocks of the same type in a row and encoding the mode as `n = (next_mode - last_mode + 4) % 5` and decoding with `next_mode = (last_mode + n + 6) % 5`.  The cost here is that a single ECN-CE-marked datagram costs 3 octets to encode.  The benefit is that you have one ACK frame; and if you don't have ECN markings, the overhead is limited to a slightly less efficient encoding of longer sequences of packets (>16 with my hack).

![Seems a little complicated](http://memedad.com/memes/1378271.jpg)

-- 
You are receiving this because you are subscribed to this thread.
Reply to this email directly or view it on GitHub:
https://github.com/quicwg/base-drafts/issues/1439#issuecomment-397157328