draft-ietf-quic-recovery-21.txt   draft-ietf-quic-recovery-22.txt 
QUIC J. Iyengar, Ed. QUIC J. Iyengar, Ed.
Internet-Draft Fastly Internet-Draft Fastly
Intended status: Standards Track I. Swett, Ed. Intended status: Standards Track I. Swett, Ed.
Expires: January 9, 2020 Google Expires: January 10, 2020 Google
July 08, 2019 July 09, 2019
QUIC Loss Detection and Congestion Control QUIC Loss Detection and Congestion Control
draft-ietf-quic-recovery-21 draft-ietf-quic-recovery-22
Abstract Abstract
This document describes loss detection and congestion control This document describes loss detection and congestion control
mechanisms for QUIC. mechanisms for QUIC.
Note to Readers Note to Readers
Discussion of this draft takes place on the QUIC working group Discussion of this draft takes place on the QUIC working group
mailing list (quic@ietf.org), which is archived at mailing list (quic@ietf.org), which is archived at
skipping to change at page 1, line 42 skipping to change at page 1, line 42
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
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working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
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Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on January 9, 2020. This Internet-Draft will expire on January 10, 2020.
Copyright Notice Copyright Notice
Copyright (c) 2019 IETF Trust and the persons identified as the Copyright (c) 2019 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info) in effect on the date of (https://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
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to this document. Code Components extracted from this document must to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Conventions and Definitions . . . . . . . . . . . . . . . . . 4 2. Conventions and Definitions . . . . . . . . . . . . . . . . . 4
3. Design of the QUIC Transmission Machinery . . . . . . . . . . 5 3. Design of the QUIC Transmission Machinery . . . . . . . . . . 5
3.1. Relevant Differences Between QUIC and TCP . . . . . . . . 5 3.1. Relevant Differences Between QUIC and TCP . . . . . . . . 6
3.1.1. Separate Packet Number Spaces . . . . . . . . . . . . 6 3.1.1. Separate Packet Number Spaces . . . . . . . . . . . . 6
3.1.2. Monotonically Increasing Packet Numbers . . . . . . . 6 3.1.2. Monotonically Increasing Packet Numbers . . . . . . . 6
3.1.3. Clearer Loss Epoch . . . . . . . . . . . . . . . . . 6 3.1.3. Clearer Loss Epoch . . . . . . . . . . . . . . . . . 7
3.1.4. No Reneging . . . . . . . . . . . . . . . . . . . . . 7 3.1.4. No Reneging . . . . . . . . . . . . . . . . . . . . . 7
3.1.5. More ACK Ranges . . . . . . . . . . . . . . . . . . . 7 3.1.5. More ACK Ranges . . . . . . . . . . . . . . . . . . . 7
3.1.6. Explicit Correction For Delayed Acknowledgements . . 7 3.1.6. Explicit Correction For Delayed Acknowledgements . . 7
4. Generating Acknowledgements . . . . . . . . . . . . . . . . . 7 4. Generating Acknowledgements . . . . . . . . . . . . . . . . . 7
4.1. Crypto Handshake Data . . . . . . . . . . . . . . . . . . 8 4.1. Crypto Handshake Data . . . . . . . . . . . . . . . . . . 8
4.2. ACK Ranges . . . . . . . . . . . . . . . . . . . . . . . 8 4.2. ACK Ranges . . . . . . . . . . . . . . . . . . . . . . . 8
4.3. Receiver Tracking of ACK Frames . . . . . . . . . . . . . 8 4.3. Receiver Tracking of ACK Frames . . . . . . . . . . . . . 8
4.4. Measuring and Reporting Host Delay . . . . . . . . . . . 8 4.4. Measuring and Reporting Host Delay . . . . . . . . . . . 9
5. Estimating the Round-Trip Time . . . . . . . . . . . . . . . 9 5. Estimating the Round-Trip Time . . . . . . . . . . . . . . . 9
5.1. Generating RTT samples . . . . . . . . . . . . . . . . . 9 5.1. Generating RTT samples . . . . . . . . . . . . . . . . . 9
5.2. Estimating min_rtt . . . . . . . . . . . . . . . . . . . 10 5.2. Estimating min_rtt . . . . . . . . . . . . . . . . . . . 10
5.3. Estimating smoothed_rtt and rttvar . . . . . . . . . . . 10 5.3. Estimating smoothed_rtt and rttvar . . . . . . . . . . . 10
6. Loss Detection . . . . . . . . . . . . . . . . . . . . . . . 11 6. Loss Detection . . . . . . . . . . . . . . . . . . . . . . . 11
6.1. Acknowledgement-based Detection . . . . . . . . . . . . . 11 6.1. Acknowledgement-based Detection . . . . . . . . . . . . . 12
6.1.1. Packet Threshold . . . . . . . . . . . . . . . . . . 12 6.1.1. Packet Threshold . . . . . . . . . . . . . . . . . . 12
6.1.2. Time Threshold . . . . . . . . . . . . . . . . . . . 12 6.1.2. Time Threshold . . . . . . . . . . . . . . . . . . . 12
6.2. Crypto Retransmission Timeout . . . . . . . . . . . . . . 13 6.2. Crypto Retransmission Timeout . . . . . . . . . . . . . . 13
6.3. Probe Timeout . . . . . . . . . . . . . . . . . . . . . . 14 6.3. Probe Timeout . . . . . . . . . . . . . . . . . . . . . . 14
6.3.1. Computing PTO . . . . . . . . . . . . . . . . . . . . 14 6.3.1. Computing PTO . . . . . . . . . . . . . . . . . . . . 15
6.3.2. Sending Probe Packets . . . . . . . . . . . . . . . . 15 6.3.2. Sending Probe Packets . . . . . . . . . . . . . . . . 15
6.3.3. Loss Detection . . . . . . . . . . . . . . . . . . . 16 6.3.3. Loss Detection . . . . . . . . . . . . . . . . . . . 16
6.4. Retry and Version Negotiation . . . . . . . . . . . . . . 16 6.4. Retry and Version Negotiation . . . . . . . . . . . . . . 16
6.5. Discarding Keys and Packet State . . . . . . . . . . . . 17 6.5. Discarding Keys and Packet State . . . . . . . . . . . . 17
6.6. Discussion . . . . . . . . . . . . . . . . . . . . . . . 17 6.6. Discussion . . . . . . . . . . . . . . . . . . . . . . . 17
7. Congestion Control . . . . . . . . . . . . . . . . . . . . . 17 7. Congestion Control . . . . . . . . . . . . . . . . . . . . . 17
7.1. Explicit Congestion Notification . . . . . . . . . . . . 18 7.1. Explicit Congestion Notification . . . . . . . . . . . . 18
7.2. Slow Start . . . . . . . . . . . . . . . . . . . . . . . 18 7.2. Slow Start . . . . . . . . . . . . . . . . . . . . . . . 18
7.3. Congestion Avoidance . . . . . . . . . . . . . . . . . . 18 7.3. Congestion Avoidance . . . . . . . . . . . . . . . . . . 18
7.4. Recovery Period . . . . . . . . . . . . . . . . . . . . . 18 7.4. Recovery Period . . . . . . . . . . . . . . . . . . . . . 18
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Appendix B. Congestion Control Pseudocode . . . . . . . . . . . 33 Appendix B. Congestion Control Pseudocode . . . . . . . . . . . 33
B.1. Constants of interest . . . . . . . . . . . . . . . . . . 33 B.1. Constants of interest . . . . . . . . . . . . . . . . . . 33
B.2. Variables of interest . . . . . . . . . . . . . . . . . . 34 B.2. Variables of interest . . . . . . . . . . . . . . . . . . 34
B.3. Initialization . . . . . . . . . . . . . . . . . . . . . 35 B.3. Initialization . . . . . . . . . . . . . . . . . . . . . 35
B.4. On Packet Sent . . . . . . . . . . . . . . . . . . . . . 35 B.4. On Packet Sent . . . . . . . . . . . . . . . . . . . . . 35
B.5. On Packet Acknowledgement . . . . . . . . . . . . . . . . 35 B.5. On Packet Acknowledgement . . . . . . . . . . . . . . . . 35
B.6. On New Congestion Event . . . . . . . . . . . . . . . . . 36 B.6. On New Congestion Event . . . . . . . . . . . . . . . . . 36
B.7. Process ECN Information . . . . . . . . . . . . . . . . . 36 B.7. Process ECN Information . . . . . . . . . . . . . . . . . 36
B.8. On Packets Lost . . . . . . . . . . . . . . . . . . . . . 37 B.8. On Packets Lost . . . . . . . . . . . . . . . . . . . . . 37
Appendix C. Change Log . . . . . . . . . . . . . . . . . . . . . 37 Appendix C. Change Log . . . . . . . . . . . . . . . . . . . . . 37
C.1. Since draft-ietf-quic-recovery-20 . . . . . . . . . . . . 37 C.1. Since draft-ietf-quic-recovery-21 . . . . . . . . . . . . 37
C.2. Since draft-ietf-quic-recovery-19 . . . . . . . . . . . . 37 C.2. Since draft-ietf-quic-recovery-20 . . . . . . . . . . . . 37
C.3. Since draft-ietf-quic-recovery-18 . . . . . . . . . . . . 38 C.3. Since draft-ietf-quic-recovery-19 . . . . . . . . . . . . 38
C.4. Since draft-ietf-quic-recovery-17 . . . . . . . . . . . . 38 C.4. Since draft-ietf-quic-recovery-18 . . . . . . . . . . . . 38
C.5. Since draft-ietf-quic-recovery-16 . . . . . . . . . . . . 39 C.5. Since draft-ietf-quic-recovery-17 . . . . . . . . . . . . 38
C.6. Since draft-ietf-quic-recovery-14 . . . . . . . . . . . . 39 C.6. Since draft-ietf-quic-recovery-16 . . . . . . . . . . . . 39
C.7. Since draft-ietf-quic-recovery-13 . . . . . . . . . . . . 40 C.7. Since draft-ietf-quic-recovery-14 . . . . . . . . . . . . 40
C.8. Since draft-ietf-quic-recovery-12 . . . . . . . . . . . . 40 C.8. Since draft-ietf-quic-recovery-13 . . . . . . . . . . . . 40
C.9. Since draft-ietf-quic-recovery-11 . . . . . . . . . . . . 40 C.9. Since draft-ietf-quic-recovery-12 . . . . . . . . . . . . 40
C.10. Since draft-ietf-quic-recovery-10 . . . . . . . . . . . . 40 C.10. Since draft-ietf-quic-recovery-11 . . . . . . . . . . . . 40
C.11. Since draft-ietf-quic-recovery-09 . . . . . . . . . . . . 40 C.11. Since draft-ietf-quic-recovery-10 . . . . . . . . . . . . 40
C.12. Since draft-ietf-quic-recovery-08 . . . . . . . . . . . . 41 C.12. Since draft-ietf-quic-recovery-09 . . . . . . . . . . . . 41
C.13. Since draft-ietf-quic-recovery-07 . . . . . . . . . . . . 41 C.13. Since draft-ietf-quic-recovery-08 . . . . . . . . . . . . 41
C.14. Since draft-ietf-quic-recovery-06 . . . . . . . . . . . . 41 C.14. Since draft-ietf-quic-recovery-07 . . . . . . . . . . . . 41
C.15. Since draft-ietf-quic-recovery-05 . . . . . . . . . . . . 41 C.15. Since draft-ietf-quic-recovery-06 . . . . . . . . . . . . 41
C.16. Since draft-ietf-quic-recovery-04 . . . . . . . . . . . . 41 C.16. Since draft-ietf-quic-recovery-05 . . . . . . . . . . . . 41
C.17. Since draft-ietf-quic-recovery-03 . . . . . . . . . . . . 41 C.17. Since draft-ietf-quic-recovery-04 . . . . . . . . . . . . 41
C.18. Since draft-ietf-quic-recovery-02 . . . . . . . . . . . . 41 C.18. Since draft-ietf-quic-recovery-03 . . . . . . . . . . . . 41
C.19. Since draft-ietf-quic-recovery-01 . . . . . . . . . . . . 41 C.19. Since draft-ietf-quic-recovery-02 . . . . . . . . . . . . 41
C.20. Since draft-ietf-quic-recovery-00 . . . . . . . . . . . . 42 C.20. Since draft-ietf-quic-recovery-01 . . . . . . . . . . . . 42
C.21. Since draft-iyengar-quic-loss-recovery-01 . . . . . . . . 42 C.21. Since draft-ietf-quic-recovery-00 . . . . . . . . . . . . 42
C.22. Since draft-iyengar-quic-loss-recovery-01 . . . . . . . . 42
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 42 Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 42
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 42 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 42
1. Introduction 1. Introduction
QUIC is a new multiplexed and secure transport atop UDP. QUIC builds QUIC is a new multiplexed and secure transport atop UDP. QUIC builds
on decades of transport and security experience, and implements on decades of transport and security experience, and implements
mechanisms that make it attractive as a modern general-purpose mechanisms that make it attractive as a modern general-purpose
transport. The QUIC protocol is described in [QUIC-TRANSPORT]. transport. The QUIC protocol is described in [QUIC-TRANSPORT].
skipping to change at page 22, line 38 skipping to change at page 22, line 38
9. IANA Considerations 9. IANA Considerations
This document has no IANA actions. Yet. This document has no IANA actions. Yet.
10. References 10. References
10.1. Normative References 10.1. Normative References
[QUIC-TLS] [QUIC-TLS]
Thomson, M., Ed. and S. Turner, Ed., "Using TLS to Secure Thomson, M., Ed. and S. Turner, Ed., "Using TLS to Secure
QUIC", draft-ietf-quic-tls-21 (work in progress), July QUIC", draft-ietf-quic-tls-22 (work in progress), July
2019. 2019.
[QUIC-TRANSPORT] [QUIC-TRANSPORT]
Iyengar, J., Ed. and M. Thomson, Ed., "QUIC: A UDP-Based Iyengar, J., Ed. and M. Thomson, Ed., "QUIC: A UDP-Based
Multiplexed and Secure Transport", draft-ietf-quic- Multiplexed and Secure Transport", draft-ietf-quic-
transport-21 (work in progress), July 2019. transport-22 (work in progress), July 2019.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>. <https://www.rfc-editor.org/info/rfc2119>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>. May 2017, <https://www.rfc-editor.org/info/rfc8174>.
skipping to change at page 37, line 37 skipping to change at page 37, line 37
if (InPersistentCongestion(largest_lost_packet)): if (InPersistentCongestion(largest_lost_packet)):
congestion_window = kMinimumWindow congestion_window = kMinimumWindow
Appendix C. Change Log Appendix C. Change Log
*RFC Editor's Note:* Please remove this section prior to *RFC Editor's Note:* Please remove this section prior to
publication of a final version of this document. publication of a final version of this document.
Issue and pull request numbers are listed with a leading octothorp. Issue and pull request numbers are listed with a leading octothorp.
C.1. Since draft-ietf-quic-recovery-20 C.1. Since draft-ietf-quic-recovery-21
o No changes
C.2. Since draft-ietf-quic-recovery-20
o Path validation can be used as initial RTT value (#2644, #2687) o Path validation can be used as initial RTT value (#2644, #2687)
o max_ack_delay transport parameter defaults to 0 (#2638, #2646) o max_ack_delay transport parameter defaults to 0 (#2638, #2646)
o Ack Delay only measures intentional delays induced by the o Ack Delay only measures intentional delays induced by the
implementation (#2596, #2786) implementation (#2596, #2786)
C.2. Since draft-ietf-quic-recovery-19 C.3. Since draft-ietf-quic-recovery-19
o Change kPersistentThreshold from an exponent to a multiplier o Change kPersistentThreshold from an exponent to a multiplier
(#2557) (#2557)
o Send a PING if the PTO timer fires and there's nothing to send o Send a PING if the PTO timer fires and there's nothing to send
(#2624) (#2624)
o Set loss delay to at least kGranularity (#2617) o Set loss delay to at least kGranularity (#2617)
o Merge application limited and sending after idle sections. Always o Merge application limited and sending after idle sections. Always
skipping to change at page 38, line 22 skipping to change at page 38, line 30
packet is ack-eliciting but the largest_acked is not (#2592) packet is ack-eliciting but the largest_acked is not (#2592)
o Don't arm the handshake timer if there is no handshake data o Don't arm the handshake timer if there is no handshake data
(#2590) (#2590)
o Clarify that the time threshold loss alarm takes precedence over o Clarify that the time threshold loss alarm takes precedence over
the crypto handshake timer (#2590, #2620) the crypto handshake timer (#2590, #2620)
o Change initial RTT to 500ms to align with RFC6298 (#2184) o Change initial RTT to 500ms to align with RFC6298 (#2184)
C.3. Since draft-ietf-quic-recovery-18 C.4. Since draft-ietf-quic-recovery-18
o Change IW byte limit to 14720 from 14600 (#2494) o Change IW byte limit to 14720 from 14600 (#2494)
o Update PTO calculation to match RFC6298 (#2480, #2489, #2490) o Update PTO calculation to match RFC6298 (#2480, #2489, #2490)
o Improve loss detection's description of multiple packet number o Improve loss detection's description of multiple packet number
spaces and pseudocode (#2485, #2451, #2417) spaces and pseudocode (#2485, #2451, #2417)
o Declare persistent congestion even if non-probe packets are sent o Declare persistent congestion even if non-probe packets are sent
and don't make persistent congestion more aggressive than RTO and don't make persistent congestion more aggressive than RTO
verified was (#2365, #2244) verified was (#2365, #2244)
o Move pseudocode to the appendices (#2408) o Move pseudocode to the appendices (#2408)
o What to send on multiple PTOs (#2380) o What to send on multiple PTOs (#2380)
C.4. Since draft-ietf-quic-recovery-17 C.5. Since draft-ietf-quic-recovery-17
o After Probe Timeout discard in-flight packets or send another o After Probe Timeout discard in-flight packets or send another
(#2212, #1965) (#2212, #1965)
o Endpoints discard initial keys as soon as handshake keys are o Endpoints discard initial keys as soon as handshake keys are
available (#1951, #2045) available (#1951, #2045)
o 0-RTT state is discarded when 0-RTT is rejected (#2300) o 0-RTT state is discarded when 0-RTT is rejected (#2300)
o Loss detection timer is cancelled when ack-eliciting frames are in o Loss detection timer is cancelled when ack-eliciting frames are in
skipping to change at page 39, line 4 skipping to change at page 39, line 14
o Endpoints discard initial keys as soon as handshake keys are o Endpoints discard initial keys as soon as handshake keys are
available (#1951, #2045) available (#1951, #2045)
o 0-RTT state is discarded when 0-RTT is rejected (#2300) o 0-RTT state is discarded when 0-RTT is rejected (#2300)
o Loss detection timer is cancelled when ack-eliciting frames are in o Loss detection timer is cancelled when ack-eliciting frames are in
flight (#2117, #2093) flight (#2117, #2093)
o Packets are declared lost if they are in flight (#2104) o Packets are declared lost if they are in flight (#2104)
o After becoming idle, either pace packets or reset the congestion o After becoming idle, either pace packets or reset the congestion
controller (#2138, 2187) controller (#2138, 2187)
o Process ECN counts before marking packets lost (#2142) o Process ECN counts before marking packets lost (#2142)
o Mark packets lost before resetting crypto_count and pto_count o Mark packets lost before resetting crypto_count and pto_count
(#2208, #2209) (#2208, #2209)
o Congestion and loss recovery state are discarded when keys are o Congestion and loss recovery state are discarded when keys are
discarded (#2327) discarded (#2327)
C.5. Since draft-ietf-quic-recovery-16 C.6. Since draft-ietf-quic-recovery-16
o Unify TLP and RTO into a single PTO; eliminate min RTO, min TLP o Unify TLP and RTO into a single PTO; eliminate min RTO, min TLP
and min crypto timeouts; eliminate timeout validation (#2114, and min crypto timeouts; eliminate timeout validation (#2114,
#2166, #2168, #1017) #2166, #2168, #1017)
o Redefine how congestion avoidance in terms of when the period o Redefine how congestion avoidance in terms of when the period
starts (#1928, #1930) starts (#1928, #1930)
o Document what needs to be tracked for packets that are in flight o Document what needs to be tracked for packets that are in flight
(#765, #1724, #1939) (#765, #1724, #1939)
skipping to change at page 39, line 42 skipping to change at page 40, line 4
o Disable RTT calculation for packets that don't elicit o Disable RTT calculation for packets that don't elicit
acknowledgment (#2060, #2078) acknowledgment (#2060, #2078)
o Limit ack_delay by max_ack_delay (#2060, #2099) o Limit ack_delay by max_ack_delay (#2060, #2099)
o Initial keys are discarded once Handshake are avaialble (#1951, o Initial keys are discarded once Handshake are avaialble (#1951,
#2045) #2045)
o Reorder ECN and loss detection in pseudocode (#2142) o Reorder ECN and loss detection in pseudocode (#2142)
o Only cancel loss detection timer if ack-eliciting packets are in o Only cancel loss detection timer if ack-eliciting packets are in
flight (#2093, #2117) flight (#2093, #2117)
C.6. Since draft-ietf-quic-recovery-14 C.7. Since draft-ietf-quic-recovery-14
o Used max_ack_delay from transport params (#1796, #1782) o Used max_ack_delay from transport params (#1796, #1782)
o Merge ACK and ACK_ECN (#1783) o Merge ACK and ACK_ECN (#1783)
C.7. Since draft-ietf-quic-recovery-13 C.8. Since draft-ietf-quic-recovery-13
o Corrected the lack of ssthresh reduction in CongestionEvent o Corrected the lack of ssthresh reduction in CongestionEvent
pseudocode (#1598) pseudocode (#1598)
o Considerations for ECN spoofing (#1426, #1626) o Considerations for ECN spoofing (#1426, #1626)
o Clarifications for PADDING and congestion control (#837, #838, o Clarifications for PADDING and congestion control (#837, #838,
#1517, #1531, #1540) #1517, #1531, #1540)
o Reduce early retransmission timer to RTT/8 (#945, #1581) o Reduce early retransmission timer to RTT/8 (#945, #1581)
o Packets are declared lost after an RTO is verified (#935, #1582) o Packets are declared lost after an RTO is verified (#935, #1582)
C.8. Since draft-ietf-quic-recovery-12 C.9. Since draft-ietf-quic-recovery-12
o Changes to manage separate packet number spaces and encryption o Changes to manage separate packet number spaces and encryption
levels (#1190, #1242, #1413, #1450) levels (#1190, #1242, #1413, #1450)
o Added ECN feedback mechanisms and handling; new ACK_ECN frame o Added ECN feedback mechanisms and handling; new ACK_ECN frame
(#804, #805, #1372) (#804, #805, #1372)
C.9. Since draft-ietf-quic-recovery-11 C.10. Since draft-ietf-quic-recovery-11
No significant changes. No significant changes.
C.10. Since draft-ietf-quic-recovery-10 C.11. Since draft-ietf-quic-recovery-10
o Improved text on ack generation (#1139, #1159) o Improved text on ack generation (#1139, #1159)
o Make references to TCP recovery mechanisms informational (#1195) o Make references to TCP recovery mechanisms informational (#1195)
o Define time_of_last_sent_handshake_packet (#1171) o Define time_of_last_sent_handshake_packet (#1171)
o Added signal from TLS the data it includes needs to be sent in a o Added signal from TLS the data it includes needs to be sent in a
Retry packet (#1061, #1199) Retry packet (#1061, #1199)
o Minimum RTT (min_rtt) is initialized with an infinite value o Minimum RTT (min_rtt) is initialized with an infinite value
(#1169) (#1169)
C.11. Since draft-ietf-quic-recovery-09 C.12. Since draft-ietf-quic-recovery-09
No significant changes. No significant changes.
C.12. Since draft-ietf-quic-recovery-08 C.13. Since draft-ietf-quic-recovery-08
o Clarified pacing and RTO (#967, #977) o Clarified pacing and RTO (#967, #977)
C.13. Since draft-ietf-quic-recovery-07 C.14. Since draft-ietf-quic-recovery-07
o Include Ack Delay in RTO(and TLP) computations (#981) o Include Ack Delay in RTO(and TLP) computations (#981)
o Ack Delay in SRTT computation (#961) o Ack Delay in SRTT computation (#961)
o Default RTT and Slow Start (#590) o Default RTT and Slow Start (#590)
o Many editorial fixes. o Many editorial fixes.
C.14. Since draft-ietf-quic-recovery-06 C.15. Since draft-ietf-quic-recovery-06
No significant changes. No significant changes.
C.15. Since draft-ietf-quic-recovery-05 C.16. Since draft-ietf-quic-recovery-05
o Add more congestion control text (#776) o Add more congestion control text (#776)
C.16. Since draft-ietf-quic-recovery-04 C.17. Since draft-ietf-quic-recovery-04
No significant changes. No significant changes.
C.17. Since draft-ietf-quic-recovery-03 C.18. Since draft-ietf-quic-recovery-03
No significant changes. No significant changes.
C.18. Since draft-ietf-quic-recovery-02 C.19. Since draft-ietf-quic-recovery-02
o Integrate F-RTO (#544, #409) o Integrate F-RTO (#544, #409)
o Add congestion control (#545, #395) o Add congestion control (#545, #395)
o Require connection abort if a skipped packet was acknowledged o Require connection abort if a skipped packet was acknowledged
(#415) (#415)
o Simplify RTO calculations (#142, #417) o Simplify RTO calculations (#142, #417)
C.19. Since draft-ietf-quic-recovery-01 C.20. Since draft-ietf-quic-recovery-01
o Overview added to loss detection o Overview added to loss detection
o Changes initial default RTT to 100ms o Changes initial default RTT to 100ms
o Added time-based loss detection and fixes early retransmit o Added time-based loss detection and fixes early retransmit
o Clarified loss recovery for handshake packets o Clarified loss recovery for handshake packets
o Fixed references and made TCP references informative o Fixed references and made TCP references informative
C.20. Since draft-ietf-quic-recovery-00 C.21. Since draft-ietf-quic-recovery-00
o Improved description of constants and ACK behavior o Improved description of constants and ACK behavior
C.21. Since draft-iyengar-quic-loss-recovery-01 C.22. Since draft-iyengar-quic-loss-recovery-01
o Adopted as base for draft-ietf-quic-recovery o Adopted as base for draft-ietf-quic-recovery
o Updated authors/editors list o Updated authors/editors list
o Added table of contents o Added table of contents
Acknowledgments Acknowledgments
Authors' Addresses Authors' Addresses
 End of changes. 35 change blocks. 
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