[tcpm] Questions on HyStart++ draft 02

[Junho Choi <[e-mail]>]

Hi,

I am working on QUIC implementation (https://github.com/cloudflare/quiche)
at Cloudflare. While I am researching on hystart, I came across
HyStart++ recently and I think this is a reasonable replacement of original
hystart, so I started the work based on the hystartplusplus draft 02.

This is about quic implementation but it's more general questions, so I am
posting here.

While I am implementing it, I have a few questions:

1. Section 4.2 -- each round is initialized as

   lastRoundMinRTT = currentRoundMinRTT
   currentRoundMinRTT = infinity
   rttSampleCount = 0

In the very beginning of the connection, what is "currentRoundMinRTT" when
there is no previous value?

I am using current rtt (or initial rtt value) and is it ok?

2. Section 4.2 -- When used with cubic, CA_cwnd() is based on cubic
algorithm I think.
 This means I need to do cubic variables calculation during slow start
 such as K and W_cubic. When is considered as a start of
 congestion avoidance and what W_max will be?

 Currently I use a start of limited slow start as a beginning of congestion
recovery
 and use cwnd at the time for W_max. Is my understanding correct?

Best,

-- 
Junho Choi <junho dot choi at gmail.com>