[quicwg/base-drafts] It seems the minimal packet number length should be 14 bits (#2955)

Luo Kai <notifications@github.com> Tue, 06 August 2019 02:54 UTC

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Subject: [quicwg/base-drafts] It seems the minimal packet number length should be 14 bits (#2955)
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According to the current packet number decode algorithm, if the packet number length is set to 7 bits, and the packets arrived disorder more than 64 packet numbers, the decode algorithm will not work properly. For example:

1. the current maximum packet number is 556917, and arrived packet number is 118, packet number length is 7 bits, then the arrived packet number will be decoded to 556918

2. now the current maximum packet number is 556918, and new arrived packet number is 16310 with packet number length 14 bits, then the new arrived packet number will be decoded to 556982. The packet number 556982 is correct and it is 64 bigger than 556918

3. the current maximum packet number is 556982 now, a new arrived packet number is 119 with packet number length 7 bits, then the new arrived packet number will be decoded to 557047. This number is wrong and it should be 556919. 

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