BBRv2 draft-related issues

[Fátima Fernández]

Hello!

I have a conceptual question about how BBR transitions from STARTUP to DRAIN state when packet loss occurs. It must meet the following conditions to estimate that the bottleneck is full and move to DRAIN: 

• The connection has been in fast recovery for at least one full round trip. 
• The loss rate over the time scale of a single full round trip exceeds BBRLossThresh (2%).
• There are at least BBRStartupFullLossCnt=3 discontiguous sequence ranges lost in that round trip. 

discontiguous sequence ranges lost is refered to the packet number?? I mean, do three "isolated" packet loss events have to occur in the same RTT? 

Maybe the question is obvious but we are studying QUIC and we are using quic-go implementation. It does not yet support BBR and we are trying to add it as an additional congestion mechanism.

Thank you very much in advance!:)