draft-ietf-tcpm-alternativebackoff-ecn-06.txt   draft-ietf-tcpm-alternativebackoff-ecn-07.txt 
Network Working Group N. Khademi Network Working Group N. Khademi
Internet-Draft M. Welzl Internet-Draft M. Welzl
Intended status: Experimental University of Oslo Intended status: Experimental University of Oslo
Expires: August 18, 2018 G. Armitage Expires: September 21, 2018 G. Armitage
Swinburne University of Technology Swinburne University of Technology
G. Fairhurst G. Fairhurst
University of Aberdeen University of Aberdeen
February 14, 2018 March 20, 2018
TCP Alternative Backoff with ECN (ABE) TCP Alternative Backoff with ECN (ABE)
draft-ietf-tcpm-alternativebackoff-ecn-06 draft-ietf-tcpm-alternativebackoff-ecn-07
Abstract Abstract
Active Queue Management (AQM) mechanisms allow for burst tolerance Active Queue Management (AQM) mechanisms allow for burst tolerance
while enforcing short queues to minimise the time that packets spend while enforcing short queues to minimise the time that packets spend
enqueued at a bottleneck. This can cause noticeable performance enqueued at a bottleneck. This can cause noticeable performance
degradation for TCP connections traversing such a bottleneck, degradation for TCP connections traversing such a bottleneck,
especially if there are only a few flows or their bandwidth-delay- especially if there are only a few flows or their bandwidth-delay-
product is large. An Explicit Congestion Notification (ECN) signal product is large. An Explicit Congestion Notification (ECN) signal
indicates that an AQM mechanism is used at the bottleneck, and indicates that an AQM mechanism is used at the bottleneck, and
skipping to change at page 1, line 45 skipping to change at page 1, line 45
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 https://datatracker.ietf.org/drafts/current/. Drafts is at https://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 August 18, 2018. This Internet-Draft will expire on September 21, 2018.
Copyright Notice Copyright Notice
Copyright (c) 2018 IETF Trust and the persons identified as the Copyright (c) 2018 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
skipping to change at page 3, line 11 skipping to change at page 3, line 11
The rules for ECN were originally written to be very conservative, The rules for ECN were originally written to be very conservative,
and required the congestion control algorithms of ECN-Capable and required the congestion control algorithms of ECN-Capable
transport protocols to treat ECN congestion signals exactly the same transport protocols to treat ECN congestion signals exactly the same
as they would treat an inferred packet loss [RFC3168]. as they would treat an inferred packet loss [RFC3168].
Research has demonstrated the benefits of reducing network delays Research has demonstrated the benefits of reducing network delays
that are caused by interaction of loss-based TCP congestion control that are caused by interaction of loss-based TCP congestion control
and excessive buffering [BUFFERBLOAT]. This has led to the creation and excessive buffering [BUFFERBLOAT]. This has led to the creation
of new AQM mechanisms like PIE [RFC8033] and CoDel of new AQM mechanisms like PIE [RFC8033] and CoDel
[CODEL2012][I-D.CoDel], which prevent bloated queues that are common [CODEL2012][RFC8289], which prevent bloated queues that are common
with unmanaged and excessively large buffers deployed across the with unmanaged and excessively large buffers deployed across the
Internet [BUFFERBLOAT]. Internet [BUFFERBLOAT].
The AQM mechanisms mentioned above aim to keep a sustained queue The AQM mechanisms mentioned above aim to keep a sustained queue
short while tolerating transient (short-term) packet bursts. short while tolerating transient (short-term) packet bursts.
However, currently used loss-based congestion control mechanisms However, currently used loss-based congestion control mechanisms
cannot always utilise a bottleneck link well where there are short cannot always utilise a bottleneck link well where there are short
queues. For example, a TCP sender must be able to store at least an queues. For example, a TCP sender must be able to store at least an
end-to-end bandwidth-delay product (BDP) worth of data at the end-to-end bandwidth-delay product (BDP) worth of data at the
bottleneck buffer if it is to maintain full path utilisation in the bottleneck buffer if it is to maintain full path utilisation in the
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network path. network path.
Modern AQM mechanisms can use ECN to signal the early signs of Modern AQM mechanisms can use ECN to signal the early signs of
impending queue buildup long before a tail-drop queue would be forced impending queue buildup long before a tail-drop queue would be forced
to resort to dropping packets. It is therefore appropriate for the to resort to dropping packets. It is therefore appropriate for the
transport protocol congestion control algorithm to have a more transport protocol congestion control algorithm to have a more
measured response when an early-warning signal of congestion is measured response when an early-warning signal of congestion is
received in the form of an ECN CE-marked packet. Recognizing these received in the form of an ECN CE-marked packet. Recognizing these
changes in modern AQM practices, more recent rules have relaxed the changes in modern AQM practices, more recent rules have relaxed the
strict requirement that ECN signals be treated identically to strict requirement that ECN signals be treated identically to
inferred packet loss [I-D.ECN-exp]. Following these newer, more inferred packet loss [RFC8311]. Following these newer, more flexible
flexible rules, this document defines a new sender-side-only rules, this document defines a new sender-side-only congestion
congestion control response, called "ABE" (Alternative Backoff with control response, called "ABE" (Alternative Backoff with ECN). ABE
ECN). ABE improves TCP's average throughput when routers use AQM improves TCP's average throughput when routers use AQM controlled
controlled buffers that allow for short queues only. buffers that allow for short queues only.
2. Definitions 2. Definitions
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119]. document are to be interpreted as described in RFC 2119 [RFC2119].
3. Specification 3. Specification
This specification updates the congestion control algorithm of an This specification updates the congestion control algorithm of an
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congestion loss in non-ECN-Capable TCP. That is, the TCP source congestion loss in non-ECN-Capable TCP. That is, the TCP source
halves the congestion window "cwnd" and reduces the slow start halves the congestion window "cwnd" and reduces the slow start
threshold "ssthresh". threshold "ssthresh".
Replacing this with: Replacing this with:
Receipt of a packet with the ECN-Echo flag SHOULD trigger the TCP Receipt of a packet with the ECN-Echo flag SHOULD trigger the TCP
source to set the slow start threshold (ssthresh) to 0.8 times the source to set the slow start threshold (ssthresh) to 0.8 times the
FlightSize, with a lower bound of 2 * SMSS applied to the result. FlightSize, with a lower bound of 2 * SMSS applied to the result.
As in [RFC5681], the TCP sender also reduces the cwnd value to no As in [RFC5681], the TCP sender also reduces the cwnd value to no
more than the new ssthresh value. more than the new ssthresh value. RFC 3168 section 6.1.2 provides
guidance on setting a cwnd less than 2 * SMSS.
4. Discussion 4. Discussion
Much of the technical background to ABE can be found in a research Much of the technical background to ABE can be found in a research
paper [ABE2017]. This paper used a mix of experiments, theory and paper [ABE2017]. This paper used a mix of experiments, theory and
simulations with NewReno [RFC5681] and CUBIC [I-D.CUBIC] to evaluate simulations with NewReno [RFC5681] and CUBIC [RFC8312] to evaluate
the technique. The technique was shown to present "...significant the technique. The technique was shown to present "...significant
performance gains in lightly-multiplexed [few concurrent flows] performance gains in lightly-multiplexed [few concurrent flows]
scenarios, without losing the delay-reduction benefits of deploying scenarios, without losing the delay-reduction benefits of deploying
CoDel or PIE". The performance improvement is achieved when reacting CoDel or PIE". The performance improvement is achieved when reacting
to ECN-Echo in congestion avoidance by multiplying cwnd and ssthresh to ECN-Echo in congestion avoidance (when ssthresh > cwnd) by
with a value in the range [0.7,0.85]. multiplying cwnd and ssthresh with a value in the range [0.7,0.85].
Applying ABE when cwnd <= ssthresh is not currently recommended, but
may benefit from additional attention, experimentation and
specification.
4.1. Why Use ECN to Vary the Degree of Backoff? 4.1. Why Use ECN to Vary the Degree of Backoff?
The classic rule-of-thumb dictates that a network path needs to AQM mechanisms such as CoDel [RFC8289] and PIE [RFC8033] set a delay
provide a BDP of bottleneck buffering if a TCP connection wishes to target in routers and use congestion notifications to constrain the
optimise path utilisation. A single TCP bulk transfer running queuing delays experienced by packets, rather than in response to
through such a bottleneck will have increased its congestion window
(cwnd) up to 2*BDP by the time that packet loss occurs. According to
[RFC5681], when a TCP sender detects segment loss using the
retransmission timer and the given segment has not yet been resent by
way of the retransmission timer, the value of ssthresh must be set to
no more of the maximum of half of the FlightSize and 2*SMSS. The
same equation is also used during Fast Retransmit/Fast Recovery
[RFC5681]. As a result, the TCP congestion control only allows one
BDP of packets in flight. This is just sufficient to maintain 100%
utilisation of the bottleneck on the network path.
AQM mechanisms such as CoDel [I-D.CoDel] and PIE [RFC8033] set a
delay target in routers and use congestion notifications to constrain
the queuing delays experienced by packets, rather than in response to
impending or actual bottleneck buffer exhaustion. With current impending or actual bottleneck buffer exhaustion. With current
default delay targets, CoDel and PIE both effectively emulate a default delay targets, CoDel and PIE both effectively emulate a
bottleneck with a short queue (section II, [ABE2017]) while also bottleneck with a short queue (section II, [ABE2017]) while also
allowing short traffic bursts into the queue. This provides allowing short traffic bursts into the queue. This provides
acceptable performance for TCP connections over a path with a low acceptable performance for TCP connections over a path with a low
BDP, or in highly multiplexed scenarios (many concurrent transport BDP, or in highly multiplexed scenarios (many concurrent transport
flows). However, in a lightly-multiplexed case over a path with a flows). However, in a lightly-multiplexed case over a path with a
large BDP, conventional TCP backoff leads to gaps in packet large BDP, conventional TCP backoff leads to gaps in packet
transmission and under-utilisation of the path. transmission and under-utilisation of the path.
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increase factor [ICC2002]. The goal of this former work was to increase factor [ICC2002]. The goal of this former work was to
operate across AQM bottlenecks using Random Early Detection (RED) operate across AQM bottlenecks using Random Early Detection (RED)
that were not necessarily configured to emulate a short queue (The that were not necessarily configured to emulate a short queue (The
current usage of RED as an Internet AQM method is limited [RFC7567]). current usage of RED as an Internet AQM method is limited [RFC7567]).
4.2. Focus on ECN as Defined in RFC3168 4.2. Focus on ECN as Defined in RFC3168
Some transport protocol mechanisms rely on ECN semantics that differ Some transport protocol mechanisms rely on ECN semantics that differ
from the original ECN definition [RFC3168]. For instance, Accurate from the original ECN definition [RFC3168]. For instance, Accurate
ECN [I-D.ietf-tcpm-accurate-ecn] permits more frequent and detailed ECN [I-D.ietf-tcpm-accurate-ecn] permits more frequent and detailed
feedback. Use of mechanisms (such as Accurate ECN, Datacenter TCP feedback. Use of such mechanisms (including Accurate ECN, Datacenter
(DCTCP) [RFC8257], or Congestion Exposure (ConEx) [RFC7713]) is out TCP (DCTCP) [RFC8257], or Congestion Exposure (ConEx) [RFC7713]) is
of scope for this document. This specification focuses on ECN as out of scope for this document. This specification focuses on ECN as
defined in [RFC3168]. defined in [RFC3168].
4.3. Choice of ABE Multiplier 4.3. Choice of ABE Multiplier
ABE decouples the reaction of a TCP sender to inferred packet loss ABE decouples the reaction of a TCP sender to inferred packet loss
and ECN-signalled congestion in the congestion avoidance phase. To and ECN-signalled congestion in the congestion avoidance phase. To
achieve this, ABE uses different the scaling factor in Equation 4 in achieve this, ABE uses a different scaling factor in Equation 4 in
Section 3.1 of [RFC5681]. The description respectively uses Section 3.1 of [RFC5681]. The description respectively uses
beta_{loss} and beta_{ecn} to refer to the multiplicative decrease beta_{loss} and beta_{ecn} to refer to the multiplicative decrease
factors applied in response to inferred packet loss, and in response factors applied in response to inferred packet loss, and in response
to a receiver indicating ECN-signalled congestion. For non-ECN- to a receiver indicating ECN-signalled congestion. For non-ECN-
enabled TCP connections, only beta_{loss} applies. enabled TCP connections, only beta_{loss} applies.
In other words, in response to inferred packet loss: In other words, in response to inferred packet loss:
ssthresh = max (FlightSize * beta_{loss}, 2 * SMSS) ssthresh = max (FlightSize * beta_{loss}, 2 * SMSS)
and in response to an indication of an ECN-signalled congestion: and in response to an indication of an ECN-signalled congestion:
ssthresh = max (FlightSize * beta_{ecn}, 2 * SMSS) ssthresh = max (FlightSize * beta_{ecn}, 2 * SMSS)
and and
cwnd = ssthresh cwnd = ssthresh
(If ssthresh == 2 * SMSS, RFC 3168 section 6.1.2 provides guidance
on setting a cwnd lower than 2 * SMSS.)
where FlightSize is the amount of outstanding data in the network, where FlightSize is the amount of outstanding data in the network,
upper-bounded by the smaller of the sender's cwnd and the receiver's upper-bounded by the smaller of the sender's cwnd and the receiver's
advertised window (rwnd) [RFC5681]. The higher the values of advertised window (rwnd) [RFC5681]. The higher the values of
beta_{loss} and beta_{ecn}, the less aggressive the response of any beta_{loss} and beta_{ecn}, the less aggressive the response of any
individual backoff event. individual backoff event.
The appropriate choice for beta_{loss} and beta_{ecn} values is a The appropriate choice for beta_{loss} and beta_{ecn} values is a
balancing act between path utilisation and draining the bottleneck balancing act between path utilisation and draining the bottleneck
queue. More aggressive backoff (smaller beta_*) risks underutilising queue. More aggressive backoff (smaller beta_*) risks underutilising
the path, while less aggressive backoff (larger beta_*) can result in the path, while less aggressive backoff (larger beta_*) can result in
slower draining of the bottleneck queue. slower draining of the bottleneck queue.
The Internet has already been running with at least two different The Internet has already been running with at least two different
beta_{loss} values for several years: the standard value is 0.5 beta_{loss} values for several years: the standard value is 0.5
[RFC5681], and the Linux implementation of CUBIC [I-D.CUBIC] has used [RFC5681], and the Linux implementation of CUBIC [RFC8312] has used a
a multiplier of 0.7 since kernel version 2.6.25 released in 2008. multiplier of 0.7 since kernel version 2.6.25 released in 2008. ABE
ABE proposes no change to beta_{loss} used by current TCP proposes no change to beta_{loss} used by current TCP
implementations. implementations.
The recommendation in Section 3 in this document corresponds to a The recommendation in Section 3 in this document corresponds to a
value of beta_{ecn}=0.8. This recommended beta_{ecn} value is only value of beta_{ecn}=0.8. This recommended beta_{ecn} value is only
applicable for the standard TCP congestion control [RFC5681]. The applicable for the standard TCP congestion control [RFC5681]. The
selection of beta_{ecn} enables tuning the response of a TCP selection of beta_{ecn} enables tuning the response of a TCP
connection to shallow AQM marking thresholds. beta_{loss} connection to shallow AQM marking thresholds. beta_{loss}
characterizes the response of a congestion control algorithm to characterizes the response of a congestion control algorithm to
packet loss, i.e., exhaustion of buffers (of unknown depth). packet loss, i.e., exhaustion of buffers (of unknown depth).
Different values for beta_{loss} have been suggested for TCP Different values for beta_{loss} have been suggested for TCP
congestion control algorithms. Consequently, beta_{ecn} is likely to congestion control algorithms. Consequently, beta_{ecn} is likely to
be an algorithm-specific parameter rather than a constant multiple of be an algorithm-specific parameter rather than a constant multiple of
the algorithm's existing beta_{loss}. the algorithm's existing beta_{loss}.
A range of tests (section IV, [ABE2017]) with NewReno and CUBIC over A range of tests (section IV, [ABE2017]) with NewReno and CUBIC over
CoDel and PIE in lightly-multiplexed scenarios have explored this CoDel and PIE in lightly-multiplexed scenarios have explored this
choice of parameter. The results of these tests indicate that CUBIC choice of parameter. The results of these tests indicate that CUBIC
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5. ABE Deployment Requirements 5. ABE Deployment Requirements
This update is a sender-side only change. Like other changes to This update is a sender-side only change. Like other changes to
congestion control algorithms, it does not require any change to the congestion control algorithms, it does not require any change to the
TCP receiver or to network devices. It does not require any ABE- TCP receiver or to network devices. It does not require any ABE-
specific changes in routers or the use of Accurate ECN feedback specific changes in routers or the use of Accurate ECN feedback
[I-D.ietf-tcpm-accurate-ecn] by a receiver. [I-D.ietf-tcpm-accurate-ecn] by a receiver.
RFC3168 states that the congestion control response to an ECN- RFC3168 states that the congestion control response to an ECN-
signalled congestion is the same as the response to a dropped packet signalled congestion is the same as the response to a dropped packet
[RFC3168]. [I-D.ECN-exp] updates this specification to allow systems [RFC3168]. [RFC8311] updates this specification to allow systems to
to provide a different behaviour when they experience ECN-signalled provide a different behaviour when they experience ECN-signalled
congestion rather than packet loss. The present specification congestion rather than packet loss. The present specification
defines such an experiment and has thus been assigned an Experimental defines such an experiment and has thus been assigned an Experimental
status before being proposed as a Standards-Track update. status before being proposed as a Standards-Track update.
The purpose of the Internet experiment is to collect experience with The purpose of the Internet experiment is to collect experience with
deployment of ABE, and confirm the safety in deployed networks using deployment of ABE, and confirm the safety in deployed networks using
this update to TCP congestion control. this update to TCP congestion control.
When used with bottlenecks that do not support ECN-marking the When used with bottlenecks that do not support ECN-marking the
specification does not modify the transport protocol. specification does not modify the transport protocol.
skipping to change at page 8, line 51 skipping to change at page 8, line 46
XX RFC ED - PLEASE REMOVE THIS SECTION XXX XX RFC ED - PLEASE REMOVE THIS SECTION XXX
This document includes no request to IANA. This document includes no request to IANA.
8. Implementation Status 8. Implementation Status
ABE is implemented as a patch for Linux and FreeBSD. It is meant for ABE is implemented as a patch for Linux and FreeBSD. It is meant for
research and available for download from research and available for download from
http://heim.ifi.uio.no/naeemk/research/ABE/. This code was used to http://heim.ifi.uio.no/naeemk/research/ABE/. This code was used to
produce the test results that are reported in [ABE2017]. An evolved produce the test results that are reported in [ABE2017]. The FreeBSD
version of the patch for FreeBSD is currently under review for code has been committed to the mainline kernel on March 19, 2018
potential inclusion in the mainline kernel [ABE-FreeBSD]. [ABE-FreeBSD].
9. Security Considerations 9. Security Considerations
The described method is a sender-side only transport change, and does The described method is a sender-side only transport change, and does
not change the protocol messages exchanged. The security not change the protocol messages exchanged. The security
considerations for ECN [RFC3168] therefore still apply. considerations for ECN [RFC3168] therefore still apply.
This is a change to TCP congestion control with ECN that will This is a change to TCP congestion control with ECN that will
typically lead to a change in the capacity achieved when flows share typically lead to a change in the capacity achieved when flows share
a network bottleneck. This could result in some flows receiving more a network bottleneck. This could result in some flows receiving more
than their fair share of capacity. Similar unfairness in the way than their fair share of capacity. Similar unfairness in the way
that capacity is shared is also exhibited by other congestion control that capacity is shared is also exhibited by other congestion control
mechanisms that have been in use in the Internet for many years mechanisms that have been in use in the Internet for many years
(e.g., CUBIC [I-D.CUBIC]). Unfairness may also be a result of other (e.g., CUBIC [RFC8312]). Unfairness may also be a result of other
factors, including the round trip time experienced by a flow. ABE factors, including the round trip time experienced by a flow. ABE
applies only when ECN-marked packets are received, not when packets applies only when ECN-marked packets are received, not when packets
are lost, hence use of ABE cannot lead to congestion collapse. are lost, hence use of ABE cannot lead to congestion collapse.
10. Revision Information 10. Revision Information
XX RFC ED - PLEASE REMOVE THIS SECTION XXX XX RFC ED - PLEASE REMOVE THIS SECTION XXX
-07. Addressed comments following WGLC.
o Updated Reference citations
o Removed paragraph containing a wrong statement related to timeout
in section 4.1.
o Discuss what happens when cwnd <= ssthresh
o Added text on Concern about lower bound of 2*SMSS
-06. Addressed Michael Scharf's comments. -06. Addressed Michael Scharf's comments.
-05. Refined the description of the experiment based on feedback at -05. Refined the description of the experiment based on feedback at
IETF-100. Incorporated comments from David Black. IETF-100. Incorporated comments from David Black.
-04. Incorporates review comments from Lawrence Stewart and the -04. Incorporates review comments from Lawrence Stewart and the
remaining comments from Roland Bless. References are updated. remaining comments from Roland Bless. References are updated.
-03. Several review comments from Roland Bless are addressed. -03. Several review comments from Roland Bless are addressed.
Consistent terminology and equations. Clarification on the scope of Consistent terminology and equations. Clarification on the scope of
skipping to change at page 10, line 29 skipping to change at page 10, line 37
Individual draft -00. draft-khademi-tsvwg-ecn-response-00 and draft- Individual draft -00. draft-khademi-tsvwg-ecn-response-00 and draft-
khademi-tcpm-alternativebackoff-ecn-00 replace draft-khademi- khademi-tcpm-alternativebackoff-ecn-00 replace draft-khademi-
alternativebackoff-ecn-03, following discussion in the TSVWG and TCPM alternativebackoff-ecn-03, following discussion in the TSVWG and TCPM
working groups. working groups.
11. References 11. References
11.1. Normative References 11.1. Normative References
[I-D.ECN-exp]
Black, D., "Explicit Congestion Notification (ECN)
Experimentation", Internet-draft, IETF work-in-progress
draft-ietf-tsvwg-ecn-experimentation-08, November 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,
<https://www.rfc-editor.org/info/rfc2119>. <https://www.rfc-editor.org/info/rfc2119>.
[RFC3168] Ramakrishnan, K., Floyd, S., and D. Black, "The Addition [RFC3168] Ramakrishnan, K., Floyd, S., and D. Black, "The Addition
of Explicit Congestion Notification (ECN) to IP", of Explicit Congestion Notification (ECN) to IP",
RFC 3168, DOI 10.17487/RFC3168, September 2001, RFC 3168, DOI 10.17487/RFC3168, September 2001,
<https://www.rfc-editor.org/info/rfc3168>. <https://www.rfc-editor.org/info/rfc3168>.
skipping to change at page 11, line 10 skipping to change at page 11, line 15
[RFC7567] Baker, F., Ed. and G. Fairhurst, Ed., "IETF [RFC7567] Baker, F., Ed. and G. Fairhurst, Ed., "IETF
Recommendations Regarding Active Queue Management", Recommendations Regarding Active Queue Management",
BCP 197, RFC 7567, DOI 10.17487/RFC7567, July 2015, BCP 197, RFC 7567, DOI 10.17487/RFC7567, July 2015,
<https://www.rfc-editor.org/info/rfc7567>. <https://www.rfc-editor.org/info/rfc7567>.
[RFC8257] Bensley, S., Thaler, D., Balasubramanian, P., Eggert, L., [RFC8257] Bensley, S., Thaler, D., Balasubramanian, P., Eggert, L.,
and G. Judd, "Data Center TCP (DCTCP): TCP Congestion and G. Judd, "Data Center TCP (DCTCP): TCP Congestion
Control for Data Centers", RFC 8257, DOI 10.17487/RFC8257, Control for Data Centers", RFC 8257, DOI 10.17487/RFC8257,
October 2017, <https://www.rfc-editor.org/info/rfc8257>. October 2017, <https://www.rfc-editor.org/info/rfc8257>.
[RFC8311] Black, D., "Relaxing Restrictions on Explicit Congestion
Notification (ECN) Experimentation", RFC 8311,
DOI 10.17487/RFC8311, January 2018,
<https://www.rfc-editor.org/info/rfc8311>.
11.2. Informative References 11.2. Informative References
[ABE-FreeBSD] [ABE-FreeBSD]
"ABE patch review in FreeBSD", "ABE patch review in FreeBSD",
<https://reviews.freebsd.org/D11616>. <https://svnweb.freebsd.org/
base?view=revision&revision=331214>.
[ABE2017] Khademi, N., Armitage, G., Welzl, M., Fairhurst, G., [ABE2017] Khademi, N., Armitage, G., Welzl, M., Fairhurst, G.,
Zander, S., and D. Ros, "Alternative Backoff: Achieving Zander, S., and D. Ros, "Alternative Backoff: Achieving
Low Latency and High Throughput with ECN and AQM", IFIP Low Latency and High Throughput with ECN and AQM", IFIP
NETWORKING 2017, Stockholm, Sweden, June 2017. NETWORKING 2017, Stockholm, Sweden, June 2017.
[BUFFERBLOAT] [BUFFERBLOAT]
Gettys, J. and K. Nichols, "Bufferbloat: Dark Buffers in Gettys, J. and K. Nichols, "Bufferbloat: Dark Buffers in
the Internet", November 2011. the Internet", November 2011.
[CODEL2012] [CODEL2012]
Nichols, K. and V. Jacobson, "Controlling Queue Delay", Nichols, K. and V. Jacobson, "Controlling Queue Delay",
July 2012, <http://queue.acm.org/detail.cfm?id=2209336>. July 2012, <http://queue.acm.org/detail.cfm?id=2209336>.
[I-D.CoDel]
Nichols, K., Jacobson, V., McGregor, V., and J. Iyengar,
"Controlled Delay Active Queue Management", Internet-
draft, IETF work-in-progress draft-ietf-aqm-codel-10,
October 2017.
[I-D.CUBIC]
Rhee, I., Xu, L., Ha, S., Zimmermann, A., Eggert, L., and
R. Scheffenegger, "CUBIC for Fast Long-Distance Networks",
Internet-draft, IETF work-in-progress draft-ietf-tcpm-
cubic-07, November 2017.
[I-D.ietf-tcpm-accurate-ecn] [I-D.ietf-tcpm-accurate-ecn]
Briscoe, B., Kuehlewind, M., and R. Scheffenegger, "More Briscoe, B., Kuehlewind, M., and R. Scheffenegger, "More
Accurate ECN Feedback in TCP", draft-ietf-tcpm-accurate- Accurate ECN Feedback in TCP", draft-ietf-tcpm-accurate-
ecn-03 (work in progress), May 2017. ecn-06 (work in progress), March 2018.
[ICC2002] Kwon, M. and S. Fahmy, "TCP Increase/Decrease Behavior [ICC2002] Kwon, M. and S. Fahmy, "TCP Increase/Decrease Behavior
with Explicit Congestion Notification (ECN)", IEEE with Explicit Congestion Notification (ECN)", IEEE
ICC 2002, New York, New York, USA, May 2002, ICC 2002, New York, New York, USA, May 2002,
<http://dx.doi.org/10.1109/ICC.2002.997262>. <http://dx.doi.org/10.1109/ICC.2002.997262>.
[RFC7713] Mathis, M. and B. Briscoe, "Congestion Exposure (ConEx) [RFC7713] Mathis, M. and B. Briscoe, "Congestion Exposure (ConEx)
Concepts, Abstract Mechanism, and Requirements", RFC 7713, Concepts, Abstract Mechanism, and Requirements", RFC 7713,
DOI 10.17487/RFC7713, December 2015, DOI 10.17487/RFC7713, December 2015,
<https://www.rfc-editor.org/info/rfc7713>. <https://www.rfc-editor.org/info/rfc7713>.
skipping to change at page 12, line 21 skipping to change at page 12, line 21
"Proportional Integral Controller Enhanced (PIE): A "Proportional Integral Controller Enhanced (PIE): A
Lightweight Control Scheme to Address the Bufferbloat Lightweight Control Scheme to Address the Bufferbloat
Problem", RFC 8033, DOI 10.17487/RFC8033, February 2017, Problem", RFC 8033, DOI 10.17487/RFC8033, February 2017,
<https://www.rfc-editor.org/info/rfc8033>. <https://www.rfc-editor.org/info/rfc8033>.
[RFC8087] Fairhurst, G. and M. Welzl, "The Benefits of Using [RFC8087] Fairhurst, G. and M. Welzl, "The Benefits of Using
Explicit Congestion Notification (ECN)", RFC 8087, Explicit Congestion Notification (ECN)", RFC 8087,
DOI 10.17487/RFC8087, March 2017, DOI 10.17487/RFC8087, March 2017,
<https://www.rfc-editor.org/info/rfc8087>. <https://www.rfc-editor.org/info/rfc8087>.
[RFC8289] Nichols, K., Jacobson, V., McGregor, A., Ed., and J.
Iyengar, Ed., "Controlled Delay Active Queue Management",
RFC 8289, DOI 10.17487/RFC8289, January 2018,
<https://www.rfc-editor.org/info/rfc8289>.
[RFC8312] Rhee, I., Xu, L., Ha, S., Zimmermann, A., Eggert, L., and
R. Scheffenegger, "CUBIC for Fast Long-Distance Networks",
RFC 8312, DOI 10.17487/RFC8312, February 2018,
<https://www.rfc-editor.org/info/rfc8312>.
Authors' Addresses Authors' Addresses
Naeem Khademi Naeem Khademi
University of Oslo University of Oslo
PO Box 1080 Blindern PO Box 1080 Blindern
Oslo N-0316 Oslo N-0316
Norway Norway
Email: naeemk@ifi.uio.no Email: naeemk@ifi.uio.no
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