Loss detection fencepost error

[michael-eriksson]

There seems (to me) to be a fencepost error in the discussion about Setting the Reordering Threshold value. I think that the Reordering Threshold value should be set to the same value as RFC 9000's kPacketThreshold.

Example: Loss detection with kPacketThreshold set to 3 would perfectly catch the reported missing packets in the Table 1 example. Please check the pseudocode in A.10 of RFC 9002, where the condition for declaring a packet as lost is:

largest_acked_packet (5) >= unacked.packet_number (2) + kPacketThreshold (3)

See also the quicdev Slack message: https://quicdev.slack.com/archives/CTDAH4H71/p1725959899164449