draft-ietf-quic-recovery-04.txt		draft-ietf-quic-recovery-05.txt
	QUIC J. Iyengar, Ed.		QUIC J. Iyengar, Ed.
	Internet-Draft I. Swett, Ed.		Internet-Draft I. Swett, Ed.
	Intended status: Standards Track Google		Intended status: Standards Track Google
	Expires: December 15, 2017 June 13, 2017		Expires: February 16, 2018 August 15, 2017
	QUIC Loss Detection and Congestion Control		QUIC Loss Detection and Congestion Control
	draft-ietf-quic-recovery-04		draft-ietf-quic-recovery-05
	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 41 ¶		skipping to change at page 1, line 41 ¶
	Internet-Drafts are working documents of the Internet Engineering		Internet-Drafts are working documents of the Internet Engineering
	Task Force (IETF). Note that other groups may also distribute		Task Force (IETF). Note that other groups may also distribute
	working documents as Internet-Drafts. The list of current Internet-		working documents as Internet-Drafts. The list of current Internet-
	Drafts is at http://datatracker.ietf.org/drafts/current/.		Drafts is at http://datatracker.ietf.org/drafts/current/.
	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 December 15, 2017.		This Internet-Draft will expire on February 16, 2018.
	Copyright Notice		Copyright Notice
	Copyright (c) 2017 IETF Trust and the persons identified as the		Copyright (c) 2017 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
	(http://trustee.ietf.org/license-info) in effect on the date of		(http://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
	skipping to change at page 2, line 27 ¶		skipping to change at page 2, line 27 ¶
	2.1. Relevant Differences Between QUIC and TCP . . . . . . . . 4		2.1. Relevant Differences Between QUIC and TCP . . . . . . . . 4
	2.1.1. Monotonically Increasing Packet Numbers . . . . . . . 4		2.1.1. Monotonically Increasing Packet Numbers . . . . . . . 4
	2.1.2. No Reneging . . . . . . . . . . . . . . . . . . . . . 4		2.1.2. No Reneging . . . . . . . . . . . . . . . . . . . . . 4
	2.1.3. More ACK Ranges . . . . . . . . . . . . . . . . . . . 5		2.1.3. More ACK Ranges . . . . . . . . . . . . . . . . . . . 5
	2.1.4. Explicit Correction For Delayed Acks . . . . . . . . 5		2.1.4. Explicit Correction For Delayed Acks . . . . . . . . 5
	3. Loss Detection . . . . . . . . . . . . . . . . . . . . . . . 5		3. Loss Detection . . . . . . . . . . . . . . . . . . . . . . . 5
	3.1. Overview . . . . . . . . . . . . . . . . . . . . . . . . 5		3.1. Overview . . . . . . . . . . . . . . . . . . . . . . . . 5
	3.2. Algorithm Details . . . . . . . . . . . . . . . . . . . . 6		3.2. Algorithm Details . . . . . . . . . . . . . . . . . . . . 6
	3.2.1. Constants of interest . . . . . . . . . . . . . . . . 6		3.2.1. Constants of interest . . . . . . . . . . . . . . . . 6
	3.2.2. Variables of interest . . . . . . . . . . . . . . . . 6		3.2.2. Variables of interest . . . . . . . . . . . . . . . . 6
	3.2.3. Initialization . . . . . . . . . . . . . . . . . . . 7		3.2.3. Initialization . . . . . . . . . . . . . . . . . . . 8
	3.2.4. On Sending a Packet . . . . . . . . . . . . . . . . . 8		3.2.4. On Sending a Packet . . . . . . . . . . . . . . . . . 8
	3.2.5. On Ack Receipt . . . . . . . . . . . . . . . . . . . 8		3.2.5. On Ack Receipt . . . . . . . . . . . . . . . . . . . 9
	3.2.6. On Packet Acknowledgment . . . . . . . . . . . . . . 9		3.2.6. On Packet Acknowledgment . . . . . . . . . . . . . . 9
	3.2.7. Setting the Loss Detection Alarm . . . . . . . . . . 10		3.2.7. Setting the Loss Detection Alarm . . . . . . . . . . 10
	3.2.8. On Alarm Firing . . . . . . . . . . . . . . . . . . . 12		3.2.8. On Alarm Firing . . . . . . . . . . . . . . . . . . . 12
	3.2.9. Detecting Lost Packets . . . . . . . . . . . . . . . 12		3.2.9. Detecting Lost Packets . . . . . . . . . . . . . . . 13
	3.3. Discussion . . . . . . . . . . . . . . . . . . . . . . . 13		3.3. Discussion . . . . . . . . . . . . . . . . . . . . . . . 14
	4. Congestion Control . . . . . . . . . . . . . . . . . . . . . 14		4. Congestion Control . . . . . . . . . . . . . . . . . . . . . 14
	4.1. Slow Start . . . . . . . . . . . . . . . . . . . . . . . 14		4.1. Slow Start . . . . . . . . . . . . . . . . . . . . . . . 15
	4.2. Recovery . . . . . . . . . . . . . . . . . . . . . . . . 14		4.2. Recovery . . . . . . . . . . . . . . . . . . . . . . . . 15
	4.3. Constants of interest . . . . . . . . . . . . . . . . . . 14		4.3. Constants of interest . . . . . . . . . . . . . . . . . . 15
	4.4. Variables of interest . . . . . . . . . . . . . . . . . . 14		4.4. Variables of interest . . . . . . . . . . . . . . . . . . 15
	4.5. Initialization . . . . . . . . . . . . . . . . . . . . . 15		4.5. Initialization . . . . . . . . . . . . . . . . . . . . . 16
	4.6. On Packet Acknowledgement . . . . . . . . . . . . . . . . 15		4.6. On Packet Acknowledgement . . . . . . . . . . . . . . . . 16
	4.7. On Packets Lost . . . . . . . . . . . . . . . . . . . . . 15		4.7. On Packets Lost . . . . . . . . . . . . . . . . . . . . . 16
	4.8. On Retransmission Timeout Verified . . . . . . . . . . . 16		4.8. On Retransmission Timeout Verified . . . . . . . . . . . 17
	4.9. Pacing Packets . . . . . . . . . . . . . . . . . . . . . 16		4.9. Pacing Packets . . . . . . . . . . . . . . . . . . . . . 17
	5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16		5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 17
	6. References . . . . . . . . . . . . . . . . . . . . . . . . . 16		6. References . . . . . . . . . . . . . . . . . . . . . . . . . 17
	6.1. Normative References . . . . . . . . . . . . . . . . . . 16		6.1. Normative References . . . . . . . . . . . . . . . . . . 17
	6.2. Informative References . . . . . . . . . . . . . . . . . 16		6.2. Informative References . . . . . . . . . . . . . . . . . 17
	Appendix A. Acknowledgments . . . . . . . . . . . . . . . . . . 17		Appendix A. Acknowledgments . . . . . . . . . . . . . . . . . . 18
	Appendix B. Change Log . . . . . . . . . . . . . . . . . . . . . 17		Appendix B. Change Log . . . . . . . . . . . . . . . . . . . . . 18
	B.1. Since draft-ietf-quic-recovery-02 . . . . . . . . . . . . 17		B.1. Since draft-ietf-quic-recovery-04 . . . . . . . . . . . . 18
	B.2. Since draft-ietf-quic-recovery-01 . . . . . . . . . . . . 18		B.2. Since draft-ietf-quic-recovery-03 . . . . . . . . . . . . 18
	B.3. Since draft-ietf-quic-recovery-00 . . . . . . . . . . . . 18		B.3. Since draft-ietf-quic-recovery-02 . . . . . . . . . . . . 18
	B.4. Since draft-iyengar-quic-loss-recovery-01 . . . . . . . . 18		B.4. Since draft-ietf-quic-recovery-01 . . . . . . . . . . . . 19
	Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 18		B.5. Since draft-ietf-quic-recovery-00 . . . . . . . . . . . . 19
			B.6. Since draft-iyengar-quic-loss-recovery-01 . . . . . . . . 19
			Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 19
	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].
	QUIC implements the spirit of known TCP loss recovery mechanisms,		QUIC implements the spirit of known TCP loss recovery mechanisms,
	described in RFCs, various Internet-drafts, and also those prevalent		described in RFCs, various Internet-drafts, and also those prevalent
	skipping to change at page 7, line 19 ¶		skipping to change at page 7, line 19 ¶
	without receiving an ack.		without receiving an ack.
	rto_count: The number of times an rto has been sent without		rto_count: The number of times an rto has been sent without
	receiving an ack.		receiving an ack.
	largest_sent_before_rto: The last packet number sent prior to the		largest_sent_before_rto: The last packet number sent prior to the
	first retransmission timeout.		first retransmission timeout.
	time_of_last_sent_packet: The time the most recent packet was sent.		time_of_last_sent_packet: The time the most recent packet was sent.
			largest_sent_packet: The packet number of the most recently sent
			packet.
			largest_acked_packet: The largest packet number acknowledged in an
			ack frame.
	latest_rtt: The most recent RTT measurement made when receiving an		latest_rtt: The most recent RTT measurement made when receiving an
	ack for a previously unacked packet.		ack for a previously unacked packet.
	smoothed_rtt: The smoothed RTT of the connection, computed as		smoothed_rtt: The smoothed RTT of the connection, computed as
	described in [RFC6298]		described in [RFC6298]
	rttvar: The RTT variance, computed as described in [RFC6298]		rttvar: The RTT variance, computed as described in [RFC6298]
	reordering_threshold: The largest delta between the largest acked		reordering_threshold: The largest delta between the largest acked
	retransmittable packet and a packet containing retransmittable		retransmittable packet and a packet containing retransmittable
	skipping to change at page 8, line 20 ¶		skipping to change at page 8, line 25 ¶
	reordering_threshold = infinite		reordering_threshold = infinite
	time_reordering_fraction = kTimeReorderingFraction		time_reordering_fraction = kTimeReorderingFraction
	else:		else:
	reordering_threshold = kReorderingThreshold		reordering_threshold = kReorderingThreshold
	time_reordering_fraction = infinite		time_reordering_fraction = infinite
	loss_time = 0		loss_time = 0
	smoothed_rtt = 0		smoothed_rtt = 0
	rttvar = 0		rttvar = 0
	largest_sent_before_rto = 0		largest_sent_before_rto = 0
	time_of_last_sent_packet = 0		time_of_last_sent_packet = 0
			largest_sent_packet = 0
	3.2.4. On Sending a Packet		3.2.4. On Sending a Packet
	After any packet is sent, be it a new transmission or a rebundled		After any packet is sent, be it a new transmission or a rebundled
	transmission, the following OnPacketSent function is called. The		transmission, the following OnPacketSent function is called. The
	parameters to OnPacketSent are as follows:		parameters to OnPacketSent are as follows:
	o packet_number: The packet number of the sent packet.		o packet_number: The packet number of the sent packet.
	o is_retransmittable: A boolean that indicates whether the packet		o is_retransmittable: A boolean that indicates whether the packet
	skipping to change at page 8, line 41 ¶		skipping to change at page 9, line 6 ¶
	retransmittability of various QUIC frames is described in		retransmittability of various QUIC frames is described in
	[QUIC-TRANSPORT]. If false, it is still acceptable for an ack to		[QUIC-TRANSPORT]. If false, it is still acceptable for an ack to
	be received for this packet. However, a caller MUST NOT set		be received for this packet. However, a caller MUST NOT set
	is_retransmittable to true if an ack is not expected.		is_retransmittable to true if an ack is not expected.
	o sent_bytes: The number of bytes sent in the packet.		o sent_bytes: The number of bytes sent in the packet.
	Pseudocode for OnPacketSent follows:		Pseudocode for OnPacketSent follows:
	OnPacketSent(packet_number, is_retransmittable, sent_bytes):		OnPacketSent(packet_number, is_retransmittable, sent_bytes):
	time_of_last_sent_packet = now;		time_of_last_sent_packet = now
			largest_sent_packet = packet_number
	sent_packets[packet_number].packet_number = packet_number		sent_packets[packet_number].packet_number = packet_number
	sent_packets[packet_number].time = now		sent_packets[packet_number].time = now
	if is_retransmittable:		if is_retransmittable:
	sent_packets[packet_number].bytes = sent_bytes		sent_packets[packet_number].bytes = sent_bytes
	SetLossDetectionAlarm()		SetLossDetectionAlarm()
	3.2.5. On Ack Receipt		3.2.5. On Ack Receipt
	When an ack is received, it may acknowledge 0 or more packets.		When an ack is received, it may acknowledge 0 or more packets.
	Pseudocode for OnAckReceived and UpdateRtt follow:		Pseudocode for OnAckReceived and UpdateRtt follow:
	OnAckReceived(ack):		OnAckReceived(ack):
			largest_acked_packet = ack.largest_acked
	// If the largest acked is newly acked, update the RTT.		// If the largest acked is newly acked, update the RTT.
	if (sent_packets[ack.largest_acked]):		if (sent_packets[ack.largest_acked]):
	latest_rtt = now - sent_packets[ack.largest_acked].time		latest_rtt = now - sent_packets[ack.largest_acked].time
	if (latest_rtt > ack.ack_delay):		if (latest_rtt > ack.ack_delay):
	latest_rtt -= ack.delay		latest_rtt -= ack.delay
	UpdateRtt(latest_rtt)		UpdateRtt(latest_rtt)
	// Find all newly acked packets.		// Find all newly acked packets.
	for acked_packet in DetermineNewlyAckedPackets():		for acked_packet in DetermineNewlyAckedPackets():
	OnPacketAcked(acked_packet.packet_number)		OnPacketAcked(acked_packet.packet_number)
	skipping to change at page 10, line 6 ¶		skipping to change at page 10, line 17 ¶
	numbers that are detected as lost.		numbers that are detected as lost.
	If this is the first acknowledgement following RTO, check if the		If this is the first acknowledgement following RTO, check if the
	smallest newly acknowledged packet is one sent by the RTO, and if so,		smallest newly acknowledged packet is one sent by the RTO, and if so,
	inform congestion control of a verified RTO, similar to F-RTO		inform congestion control of a verified RTO, similar to F-RTO
	[RFC5682]		[RFC5682]
	Pseudocode for OnPacketAcked follows:		Pseudocode for OnPacketAcked follows:
	OnPacketAcked(acked_packet_number):		OnPacketAcked(acked_packet_number):
			OnPacketAckedCC(acked_packet_number)
	// If a packet sent prior to RTO was acked, then the RTO		// If a packet sent prior to RTO was acked, then the RTO
	// was spurious. Otherwise, inform congestion control.		// was spurious. Otherwise, inform congestion control.
	if (rto_count > 0 &&		if (rto_count > 0 &&
	acked_packet_number > largest_sent_before_rto)		acked_packet_number > largest_sent_before_rto)
	OnRetransmissionTimeoutVerified()		OnRetransmissionTimeoutVerified()
	handshake_count = 0		handshake_count = 0
	tlp_count = 0		tlp_count = 0
	rto_count = 0		rto_count = 0
	sent_packets.remove(acked_packet_number)		sent_packets.remove(acked_packet_number)
	skipping to change at page 10, line 29 ¶		skipping to change at page 10, line 41 ¶
	detection. The duration of the alarm is based on the alarm's mode,		detection. The duration of the alarm is based on the alarm's mode,
	which is set in the packet and timer events further below. The		which is set in the packet and timer events further below. The
	function SetLossDetectionAlarm defined below shows how the single		function SetLossDetectionAlarm defined below shows how the single
	timer is set based on the alarm mode.		timer is set based on the alarm mode.
	3.2.7.1. Handshake Packets		3.2.7.1. Handshake Packets
	The initial flight has no prior RTT sample. A client SHOULD remember		The initial flight has no prior RTT sample. A client SHOULD remember
	the previous RTT it observed when resumption is attempted and use		the previous RTT it observed when resumption is attempted and use
	that for an initial RTT value. If no previous RTT is available, the		that for an initial RTT value. If no previous RTT is available, the
	initial RTT defaults to 200ms.		initial RTT defaults to 100ms.
	Endpoints MUST retransmit handshake frames if not acknowledged within		Endpoints MUST retransmit handshake frames if not acknowledged within
	a time limit. This time limit will start as the largest of twice the		a time limit. This time limit will start as the largest of twice the
	rtt value and MinTLPTimeout. Each consecutive handshake		RTT value and MinTLPTimeout. Each consecutive handshake
	retransmission doubles the time limit, until an acknowledgement is		retransmission doubles the time limit, until an acknowledgement is
	received.		received.
	Handshake frames may be cancelled by handshake state transitions. In		Handshake frames may be cancelled by handshake state transitions. In
	particular, all non-protected frames SHOULD be no longer be		particular, all non-protected frames SHOULD be no longer be
	transmitted once packet protection is available.		transmitted once packet protection is available.
	When stateless rejects are in use, the connection is considered		When stateless rejects are in use, the connection is considered
	immediately closed once a reject is sent, so no timer is set to		immediately closed once a reject is sent, so no timer is set to
	retransmit the reject.		retransmit the reject.
	Version negotiation packets are always stateless, and MUST be sent		Version negotiation packets are always stateless, and MUST be sent
	once per per handshake packet that uses an unsupported QUIC version,		once per handshake packet that uses an unsupported QUIC version, and
	and MAY be sent in response to 0RTT packets.		MAY be sent in response to 0RTT packets.
	3.2.7.2. Tail Loss Probe and Retransmission Timeout		3.2.7.2. Tail Loss Probe and Retransmission Timeout
	Tail loss probes [LOSS-PROBE] and retransmission timeouts [RFC6298]		Tail loss probes [LOSS-PROBE] and retransmission timeouts [RFC6298]
	are an alarm based mechanism to recover from cases when there are		are an alarm based mechanism to recover from cases when there are
	outstanding retransmittable packets, but an acknowledgement has not		outstanding retransmittable packets, but an acknowledgement has not
	been received in a timely manner.		been received in a timely manner.
	3.2.7.3. Early Retransmit		3.2.7.3. Early Retransmit
	skipping to change at page 14, line 47 ¶		skipping to change at page 15, line 42 ¶
	kLossReductionFactor (default 0.5): Reduction in congestion window		kLossReductionFactor (default 0.5): Reduction in congestion window
	when a new loss event is detected.		when a new loss event is detected.
	4.4. Variables of interest		4.4. Variables of interest
	Variables required to implement the congestion control mechanisms are		Variables required to implement the congestion control mechanisms are
	described in this section.		described in this section.
	bytes_in_flight: The sum of the size in bytes of all sent packets		bytes_in_flight: The sum of the size in bytes of all sent packets
	that contain at least one retransmittable frame, and have not been		that contain at least one retransmittable or PADDING frame, and
	acked or declared lost.		have not been acked or declared lost. The size does not include
			IP or UDP overhead. Ack only frames do not count towards
			byte_in_flight.
	congestion_window: Maximum number of bytes in flight that may be		congestion_window: Maximum number of bytes in flight that may be
	sent.		sent.
	end_of_recovery: The packet number after which QUIC will no longer		end_of_recovery: The packet number after which QUIC will no longer
	be in recovery.		be in recovery.
	ssthresh Slow start threshold in bytes. When the congestion window		ssthresh Slow start threshold in bytes. When the congestion window
	is below ssthresh, it grows by the number of bytes acknowledged		is below ssthresh, it grows by the number of bytes acknowledged
	for each ack.		for each ack.
	skipping to change at page 15, line 24 ¶		skipping to change at page 16, line 21 ¶
	At the beginning of the connection, initialize the loss detection		At the beginning of the connection, initialize the loss detection
	variables as follows:		variables as follows:
	congestion_window = kInitialWindow		congestion_window = kInitialWindow
	bytes_in_flight = 0		bytes_in_flight = 0
	end_of_recovery = 0		end_of_recovery = 0
	ssthresh = infinite		ssthresh = infinite
	4.6. On Packet Acknowledgement		4.6. On Packet Acknowledgement
	Invoked at the same time loss detection's OnPacketAcked is called and		Invoked from loss detection's OnPacketAcked and is supplied with
	supplied with the acked_packet from sent_packets.		acked_packet from sent_packets.
	Pseudocode for OnPacketAcked follows:		Pseudocode for OnPacketAckedCC follows:
	OnPacketAcked(acked_packet):		OnPacketAckedCC(acked_packet):
	if (acked_packet.packet_number < end_of_recovery):		if (acked_packet.packet_number < end_of_recovery):
	return		return
	if (congestion_window < ssthresh):		if (congestion_window < ssthresh):
	congestion_window += acket_packets.bytes		congestion_window += acket_packets.bytes
	else:		else:
	congestion_window +=		congestion_window +=
	acked_packets.bytes / congestion_window		acked_packets.bytes / congestion_window
	4.7. On Packets Lost		4.7. On Packets Lost
	skipping to change at page 16, line 41 ¶		skipping to change at page 17, line 41 ¶
	This document has no IANA actions. Yet.		This document has no IANA actions. Yet.
	6. References		6. References
	6.1. Normative References		6.1. Normative References
	[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 (work in progress), June 2017.		transport (work in progress), August 2017.
	[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,
	<http://www.rfc-editor.org/info/rfc2119>.		<http://www.rfc-editor.org/info/rfc2119>.
	6.2. Informative References		6.2. Informative References
	[LOSS-PROBE]		[LOSS-PROBE]
	Dukkipati, N., Cardwell, N., Cheng, Y., and M. Mathis,		Dukkipati, N., Cardwell, N., Cheng, Y., and M. Mathis,
	skipping to change at page 17, line 40 ¶		skipping to change at page 18, line 40 ¶
	RFC 6582, DOI 10.17487/RFC6582, April 2012,		RFC 6582, DOI 10.17487/RFC6582, April 2012,
	<http://www.rfc-editor.org/info/rfc6582>.		<http://www.rfc-editor.org/info/rfc6582>.
	Appendix A. Acknowledgments		Appendix A. Acknowledgments
	Appendix B. Change Log		Appendix B. 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.
	B.1. Since draft-ietf-quic-recovery-02		B.1. Since draft-ietf-quic-recovery-04
			No significant changes.
			B.2. Since draft-ietf-quic-recovery-03
			No significant changes.
			B.3. 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)
	B.2. Since draft-ietf-quic-recovery-01		B.4. 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
	B.3. Since draft-ietf-quic-recovery-00		B.5. Since draft-ietf-quic-recovery-00
	o Improved description of constants and ACK behavior		o Improved description of constants and ACK behavior
	B.4. Since draft-iyengar-quic-loss-recovery-01		B.6. 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
	Authors' Addresses		Authors' Addresses
	Jana Iyengar (editor)		Jana Iyengar (editor)
End of changes. 25 change blocks.
	44 lines changed or deleted		65 lines changed or added
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