From efe6dc378389e206d05a3333e8166cf33f7054d6 Mon Sep 17 00:00:00 2001 From: ianswett Date: Mon, 22 May 2017 16:21:09 -0400 Subject: [PATCH] Declare latest_rtt And remove rtt_sample. --- draft-ietf-quic-recovery.md | 22 +++++++++++++--------- 1 file changed, 13 insertions(+), 9 deletions(-) diff --git a/draft-ietf-quic-recovery.md b/draft-ietf-quic-recovery.md index 0e65d37409..9fde7f3067 100644 --- a/draft-ietf-quic-recovery.md +++ b/draft-ietf-quic-recovery.md @@ -255,6 +255,10 @@ largest_sent_before_rto: : The last packet number sent prior to the first retransmission timeout. +latest_rtt: +: The most recent RTT measurement made when receiving an ack for + a previously unacked packet. + smoothed_rtt: : The smoothed RTT of the connection, computed as described in {{?RFC6298}} @@ -343,10 +347,10 @@ Pseudocode for OnAckReceived and UpdateRtt follow: OnAckReceived(ack): // If the largest acked is newly acked, update the RTT. if (sent_packets[ack.largest_acked]): - rtt_sample = now - sent_packets[ack.largest_acked].time - if (rtt_sample > ack.ack_delay): - rtt_sample -= ack.delay - UpdateRtt(rtt_sample) + latest_rtt = now - sent_packets[ack.largest_acked].time + if (latest_rtt > ack.ack_delay): + latest_rtt -= ack.delay + UpdateRtt(latest_rtt) // The sender may skip packets for detecting optimistic ACKs if (packets acked that the sender skipped): abortConnection() @@ -358,14 +362,14 @@ Pseudocode for OnAckReceived and UpdateRtt follow: SetLossDetectionAlarm() - UpdateRtt(rtt_sample): + UpdateRtt(latest_rtt): // Based on {{?RFC6298}}. if (smoothed_rtt == 0): - smoothed_rtt = rtt_sample - rttvar = rtt_sample / 2 + smoothed_rtt = latest_rtt + rttvar = latest_rtt / 2 else: - rttvar = 3/4 * rttvar + 1/4 * (smoothed_rtt - rtt_sample) - smoothed_rtt = 7/8 * smoothed_rtt + 1/8 * rtt_sample + rttvar = 3/4 * rttvar + 1/4 * (smoothed_rtt - latest_rtt) + smoothed_rtt = 7/8 * smoothed_rtt + 1/8 * latest_rtt ~~~ ### On Packet Acknowledgment