diff options
Diffstat (limited to 'proposals/324-rtt-congestion-control.txt')
| -rw-r--r-- | proposals/324-rtt-congestion-control.txt | 17 |
1 files changed, 14 insertions, 3 deletions
diff --git a/proposals/324-rtt-congestion-control.txt b/proposals/324-rtt-congestion-control.txt index 78d526d..0e8c349 100644 --- a/proposals/324-rtt-congestion-control.txt +++ b/proposals/324-rtt-congestion-control.txt @@ -169,10 +169,12 @@ Moving Average with alpha = 2/(N+1): N_EWMA = BDP*2/(N+1) + N_EWMA_prev*(N-1)/(N+1). -Flow control rate limiting uses this function +Flow control rate limiting uses this function. -For both RTT and SENDME BDP estimation, N is the number of SENDME acks -between congestion window updates, divided by the value of consensus +During Slow Start, N is set to `cc_ewma_ss`, for RTT estimation. + +After Slow Start, for both RTT and SENDME BDP estimation, N is the number +of SENDME acks between congestion window updates, divided by the value of consensus parameter 'cc_ewma_cwnd_pct', and then capped at a max of 'cc_ewma_max', but always at least 2: @@ -1293,6 +1295,15 @@ These are sorted in order of importance to tune, most important first. congestion, to avoid overloading slow relays. Values of 10 or 20 were best. + cc_ewma_ss: + - Description: This specifies the N in N_EWMA smoothing of RTT during + Slow Start. + - Range: [2, INT32_MAX] + - Default: 2 + - Tuning Values: [2,4] + - Shadow Tuning Results: + Setting this to 2 helped reduce overshoot during Slow Start. + cc_cwnd_inc: - Description: How much to increment the congestion window by during steady state, every cwnd. |