draft-ietf-rmcat-coupled-cc-00.txt   draft-ietf-rmcat-coupled-cc-01.txt 
RTP Media Congestion Avoidance S. Islam RTP Media Congestion Avoidance S. Islam
Techniques (rmcat) M. Welzl Techniques (rmcat) M. Welzl
Internet-Draft S. Gjessing Internet-Draft S. Gjessing
Intended status: Experimental University of Oslo Intended status: Experimental University of Oslo
Expires: March 17, 2016 September 14, 2015 Expires: September 22, 2016 March 21, 2016
Coupled congestion control for RTP media Coupled congestion control for RTP media
draft-ietf-rmcat-coupled-cc-00 draft-ietf-rmcat-coupled-cc-01
Abstract Abstract
When multiple congestion controlled RTP sessions traverse the same When multiple congestion controlled RTP sessions traverse the same
network bottleneck, it can be beneficial to combine their controls network bottleneck, it can be beneficial to combine their controls
such that the total on-the-wire behavior is improved. This document such that the total on-the-wire behavior is improved. This document
describes such a method for flows that have the same sender, in a way describes such a method for flows that have the same sender, in a way
that is as flexible and simple as possible while minimizing the that is as flexible and simple as possible while minimizing the
amount of changes needed to existing RTP applications. It specifies amount of changes needed to existing RTP applications. It specifies
how to apply the method for the NADA congestion control algorithm. how to apply the method for both the NADA and Google congestion
control algorithms.
Status of this Memo Status of this Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
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 March 17, 2016. This Internet-Draft will expire on September 22, 2016.
Copyright Notice Copyright Notice
Copyright (c) 2015 IETF Trust and the persons identified as the Copyright (c) 2016 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
carefully, as they describe your rights and restrictions with respect carefully, as they describe your rights and restrictions with respect
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
skipping to change at page 2, line 18 skipping to change at page 2, line 19
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Definitions . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Definitions . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Limitations . . . . . . . . . . . . . . . . . . . . . . . . . 4 3. Limitations . . . . . . . . . . . . . . . . . . . . . . . . . 4
4. Architectural overview . . . . . . . . . . . . . . . . . . . . 5 4. Architectural overview . . . . . . . . . . . . . . . . . . . . 5
5. Roles . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 5. Roles . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
5.1. SBD . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 5.1. SBD . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
5.2. FSE . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 5.2. FSE . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
5.3. Flows . . . . . . . . . . . . . . . . . . . . . . . . . . 7 5.3. Flows . . . . . . . . . . . . . . . . . . . . . . . . . . 7
5.3.1. Example algorithm 1 - Active FSE . . . . . . . . . . . 7 5.3.1. Example algorithm 1 - Active FSE . . . . . . . . . . . 8
5.3.2. Example algorithm 2 - Conservative Active FSE . . . . 8 5.3.2. Example algorithm 2 - Conservative Active FSE . . . . 8
6. Application . . . . . . . . . . . . . . . . . . . . . . . . . 10 6. Application . . . . . . . . . . . . . . . . . . . . . . . . . 10
6.1. NADA . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 6.1. NADA . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
6.2. General recommendations . . . . . . . . . . . . . . . . . 10 6.2. GCC . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
6.3. General recommendations . . . . . . . . . . . . . . . . . 11
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 11 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 11
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11
9. Security Considerations . . . . . . . . . . . . . . . . . . . 11 9. Security Considerations . . . . . . . . . . . . . . . . . . . 11
10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 11 10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 12
10.1. Normative References . . . . . . . . . . . . . . . . . . . 11 10.1. Normative References . . . . . . . . . . . . . . . . . . . 12
10.2. Informative References . . . . . . . . . . . . . . . . . . 12 10.2. Informative References . . . . . . . . . . . . . . . . . . 12
Appendix A. Scheduling . . . . . . . . . . . . . . . . . . . . . 13 Appendix A. Scheduling . . . . . . . . . . . . . . . . . . . . . 13
Appendix B. Example algorithm - Passive FSE . . . . . . . . . . . 13 Appendix B. Example algorithm - Passive FSE . . . . . . . . . . . 13
B.1. Example operation (passive) . . . . . . . . . . . . . . . 15 B.1. Example operation (passive) . . . . . . . . . . . . . . . 16
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 20 Appendix C. Change log . . . . . . . . . . . . . . . . . . . . . 20
C.1. draft-welzl-rmcat-coupled-cc . . . . . . . . . . . . . . . 20
C.1.1. Changes from -00 to -01 . . . . . . . . . . . . . . . 20
C.1.2. Changes from -01 to -02 . . . . . . . . . . . . . . . 20
C.1.3. Changes from -02 to -03 . . . . . . . . . . . . . . . 21
C.1.4. Changes from -03 to -04 . . . . . . . . . . . . . . . 21
C.1.5. Changes from -04 to -05 . . . . . . . . . . . . . . . 21
C.2. draft-ietf-rmcat-coupled-cc . . . . . . . . . . . . . . . 21
C.2.1. Changes from draft-welzl-rmcat-coupled-cc-05 . . . . . 21
C.2.2. Changes from -00 to -01 . . . . . . . . . . . . . . . 21
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 21
1. Introduction 1. Introduction
When there is enough data to send, a congestion controller must When there is enough data to send, a congestion controller must
increase its sending rate until the path's capacity has been reached; increase its sending rate until the path's capacity has been reached;
depending on the controller, sometimes the rate is increased further, depending on the controller, sometimes the rate is increased further,
until packets are ECN-marked or dropped. This process inevitably until packets are ECN-marked or dropped. This process inevitably
creates undesirable queuing delay -- an effect that is amplified when creates undesirable queuing delay -- an effect that is amplified when
multiple congestion controlled connections traverse the same network multiple congestion controlled connections traverse the same network
bottleneck. bottleneck.
skipping to change at page 3, line 26 skipping to change at page 3, line 26
single congestion controller. It is hard to implement because it single congestion controller. It is hard to implement because it
requires an additional congestion controller and removes all per- requires an additional congestion controller and removes all per-
connection congestion control functionality, which is quite a connection congestion control functionality, which is quite a
significant change to existing RTP based applications. This document significant change to existing RTP based applications. This document
presents a method to combine the behavior of congestion control presents a method to combine the behavior of congestion control
mechanisms that is easier to implement than the Congestion Manager mechanisms that is easier to implement than the Congestion Manager
[RFC3124] and also requires less significant changes to existing RTP [RFC3124] and also requires less significant changes to existing RTP
based applications. It attempts to roughly approximate the CM based applications. It attempts to roughly approximate the CM
behavior by sharing information between existing congestion behavior by sharing information between existing congestion
controllers. It is able to honor user-specified priorities, which is controllers. It is able to honor user-specified priorities, which is
required by rtcweb [rtcweb-usecases]. required by rtcweb [RFC7478].
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].
Available Bandwidth: Available Bandwidth:
The available bandwidth is the nominal link capacity minus the The available bandwidth is the nominal link capacity minus the
amount of traffic that traversed the link during a certain time amount of traffic that traversed the link during a certain time
skipping to change at page 5, line 21 skipping to change at page 5, line 21
it initiates communication with flows and SBD. However, in the it initiates communication with flows and SBD. However, in the
passive version, it does not actively initiate communication with passive version, it does not actively initiate communication with
flows and SBD; its only active role is internal state maintenance flows and SBD; its only active role is internal state maintenance
(e.g., an implementation could use soft state to remove a flow's data (e.g., an implementation could use soft state to remove a flow's data
after long periods of inactivity). Every time a flow's congestion after long periods of inactivity). Every time a flow's congestion
control mechanism would normally update its sending rate, the flow control mechanism would normally update its sending rate, the flow
instead updates information in the FSE and performs a query on the instead updates information in the FSE and performs a query on the
FSE, leading to a sending rate that can be different from what the FSE, leading to a sending rate that can be different from what the
congestion controller originally determined. Using information congestion controller originally determined. Using information
about/from the currently active flows, SBD updates the FSE with the about/from the currently active flows, SBD updates the FSE with the
correct Flow State Identifiers (FSIs). correct Flow State Identifiers (FSIs). This document describes both
active and passive versions, however the passive version is put into
the appendix as it is extremely experimental.
------- <--- Flow 1 ------- <--- Flow 1
| FSE | <--- Flow 2 .. | FSE | <--- Flow 2 ..
------- <--- .. Flow N ------- <--- .. Flow N
^ ^
| | | |
------- | ------- |
| SBD | <-------| | SBD | <-------|
------- -------
skipping to change at page 6, line 26 skipping to change at page 6, line 26
1. From multiplexing: it can be based on the simple assumption that 1. From multiplexing: it can be based on the simple assumption that
packets sharing the same five-tuple (IP source and destination packets sharing the same five-tuple (IP source and destination
address, protocol, and transport layer port number pair) and address, protocol, and transport layer port number pair) and
having the same Differentiated Services Code Point (DSCP) in the having the same Differentiated Services Code Point (DSCP) in the
IP header are typically treated in the same way along the path. IP header are typically treated in the same way along the path.
The latter method is the only one specified in this document: SBD The latter method is the only one specified in this document: SBD
MAY consider all flows that use the same five-tuple and DSCP to MAY consider all flows that use the same five-tuple and DSCP to
belong to the same FG. This classification applies to certain belong to the same FG. This classification applies to certain
tunnels, or RTP flows that are multiplexed over one transport tunnels, or RTP flows that are multiplexed over one transport
(cf. [transport-multiplex]). In one way or another, such (cf. [transport-multiplex]). Such multiplexing is also a
multiplexing will probably be recommended for use with rtcweb recommended usage of RTP in rtcweb [rtcweb-rtp-usage].
[rtcweb-rtp-usage].
2. Via configuration: e.g. by assuming that a common wireless uplink 2. Via configuration: e.g. by assuming that a common wireless uplink
is also a shared bottleneck. is also a shared bottleneck.
3. From measurements: e.g. by considering correlations among 3. From measurements: e.g. by considering correlations among
measured delay and loss as an indication of a shared bottleneck. measured delay and loss as an indication of a shared bottleneck.
The methods above have some essential trade-offs: e.g., multiplexing The methods above have some essential trade-offs: e.g., multiplexing
is a completely reliable measure, however it is limited in scope to is a completely reliable measure, however it is limited in scope to
two end points (i.e., it cannot be applied to couple congestion two end points (i.e., it cannot be applied to couple congestion
controllers of one sender talking to multiple receivers). A controllers of one sender talking to multiple receivers). A
measurement-based SBD mechanism is described in [sbd]. Measurements measurement-based SBD mechanism is described in [I-D.ietf-rmcat-sbd].
can never be 100% reliable, in particular because they are based on Measurements can never be 100% reliable, in particular because they
the past but applying coupled congestion control means to make an are based on the past but applying coupled congestion control means
assumption about the future; it is therefore recommended to implement to make an assumption about the future; it is therefore recommended
cautionary measures, e.g. by disabling coupled congestion control if to implement cautionary measures, e.g. by disabling coupled
enabling it causes a significant increase in delay and/or packet congestion control if enabling it causes a significant increase in
loss. Measurements also take time, which entails a certain delay for delay and/or packet loss. Measurements also take time, which entails
turning on coupling (refer to [sbd] for details). a certain delay for turning on coupling (refer to
[I-D.ietf-rmcat-sbd] for details).
5.2. FSE 5.2. FSE
The FSE contains a list of all flows that have registered with it. The FSE contains a list of all flows that have registered with it.
For each flow, it stores the following: For each flow, it stores the following:
o a unique flow number to identify the flow o a unique flow number to identify the flow
o the FGI of the FG that it belongs to (based on the definitions in o the FGI of the FG that it belongs to (based on the definitions in
this document, a flow has only one bottleneck, and can therefore this document, a flow has only one bottleneck, and can therefore
be in only one FG) be in only one FG)
o a priority P, which here is assumed to be represented as a o a priority P, which here is assumed to be represented as a
floating point number in the range from 0.1 (unimportant) to 1 floating point number in the range from 0.1 (unimportant) to 1
(very important). A negative value is used to indicate that a (very important).
flow has terminated
o The rate used by the flow in bits per second, FSE_R. o The rate used by the flow in bits per second, FSE_R.
Note that the priority does not need to be a floating point value and
its value range does not matter for this algorithm: the algorithm
works with a flow's priority portion of the sum of all priority
values. Priority values can therefore also be mapped to the "very-
low", "low", "medium" or "high" priority levels described in
[I-D.ietf-rtcweb-transports].
The FSE can operate on window-based as well as rate-based congestion The FSE can operate on window-based as well as rate-based congestion
controllers (TEMPORARY NOTE: and probably -- not yet tested -- controllers (TEMPORARY NOTE: and probably -- not yet tested --
combinations thereof, with calculations to convert from one to the combinations thereof, with calculations to convert from one to the
other). In case of a window-based controller, FSE_R is a window, and other). In case of a window-based controller, FSE_R is a window, and
all the text below should be considered to refer to window, not all the text below should be considered to refer to window, not
rates. rates.
In the FSE, each FG contains one static variable S_CR which is meant In the FSE, each FG contains one static variable S_CR which is the
to be the sum of the calculated rates of all flows in the same FG sum of the calculated rates of all flows in the same FG. This value
(including the flow itself). This value is used to calculate the is used to calculate the sending rate.
sending rate.
The information listed here is enough to implement the sample flow The information listed here is enough to implement the sample flow
algorithm given below. FSE implementations could easily be extended algorithm given below. FSE implementations could easily be extended
to store, e.g., a flow's current sending rate for statistics to store, e.g., a flow's current sending rate for statistics
gathering or future potential optimizations. gathering or future potential optimizations.
5.3. Flows 5.3. Flows
Flows register themselves with SBD and FSE when they start, Flows register themselves with SBD and FSE when they start,
deregister from the FSE when they stop, and carry out an UPDATE deregister from the FSE when they stop, and carry out an UPDATE
skipping to change at page 10, line 21 skipping to change at page 10, line 21
end for end for
6. Application 6. Application
This section specifies how the FSE can be applied to specific This section specifies how the FSE can be applied to specific
congestion control mechanisms and makes general recommendations that congestion control mechanisms and makes general recommendations that
facilitate applying the FSE to future congestion controls. facilitate applying the FSE to future congestion controls.
6.1. NADA 6.1. NADA
Network-Assisted Dynamic Adapation (NADA) [nada] is a congestion Network-Assisted Dynamic Adapation (NADA) [I-D.ietf-rmcat-nada] is a
control scheme for rtcweb. It calculates a reference rate R_n upon congestion control scheme for rtcweb. It calculates a reference rate
receiving an acknowledgment, and then, based on the reference rate, r_ref upon receiving an acknowledgment, and then, based on the
it calculates a video target rate R_v and a sending rate for the reference rate, it calculates a video target rate r_vin and a sending
flows, R_s. rate for the flows, r_send.
When applying the FSE to NADA, the UPDATE function call described in When applying the FSE to NADA, the UPDATE function call described in
Section 5.3 gives the FSE NADA's reference rate R_n. The recommended Section 5.3 gives the FSE NADA's reference rate r_ref. The
algorithm for NADA is the Active FSE in Section 5.3.1. In step 3 recommended algorithm for NADA is the Active FSE in Section 5.3.1.
(c), when the FSE_R(i) is "sent" to the flow i, this means updating In step 3 (c), when the FSE_R(i) is "sent" to the flow i, this means
R_v and R_s of flow i with the value of FSE_R(i). updating r_ref(r_vin and r_send) of flow i with the value of
FSE_R(i).
NADA simulation results are available from 6.2. GCC
http://heim.ifi.uio.no/safiquli/coupled-cc/. The next version of
this document will refer to a technical report that will be made
available at the same URL.
6.2. General recommendations Google Congestion Control (GCC) [I-D.ietf-rmcat-gcc] is another
congestion control scheme for rtcweb. The rate control of GCC
employs two parts: controlling the bandwidth estimate based on delay,
and controlling the bandwidth estimate based on loss. Both are
designed to estimate the available bandwidth, A_hat.
When applying the FSE to GCC, the UPDATE function call described in
Section 5.3 gives the FSE GCC's estimate of available bandwidth
A_hat. The recommended algorithm for GCC is the Active FSE in
Section 5.3.1. In step 3 (c), when the FSE_R(i) is "sent" to the
flow i, this means updating A_hat of flow i with the value of
FSE_R(i).
6.3. General recommendations
This section will provides general advice for applying the FSE to This section will provides general advice for applying the FSE to
congestion control mechanisms. TEMPORARY NOTE: Future versions of congestion control mechanisms. TEMPORARY NOTE: Future versions of
this document will contain a longer list. this document will contain a longer list.
Receiver-side calculations: Receiver-side calculations:
When receiver-side calculations make assumptions about the rate When receiver-side calculations make assumptions about the rate
of the sender, the calculations need to be synchronized or the of the sender, the calculations need to be synchronized or the
receiver needs to be updated accordingly. This applies to TFRC receiver needs to be updated accordingly. This applies to TFRC
[RFC5348], for example, where simulations showed somewhat less [RFC5348], for example, where simulations showed somewhat less
favorable results when using the FSE without a receiver-side favorable results when using the FSE without a receiver-side
change [fse]. change [fse].
7. Acknowledgements 7. Acknowledgements
This document has benefitted from discussions with and feedback from This document has benefitted from discussions with and feedback from
David Hayes, Mirja Kuehlewind, Andreas Petlund, David Ros (who also David Hayes, Mirja Kuehlewind, Karen Nielsen, Andreas Petlund, David
gave the FSE its name), Zaheduzzaman Sarker and Varun Singh. The Ros (who also gave the FSE its name), Zaheduzzaman Sarker, Varun
authors would like to thank Xiaoqing Zhu for helping with NADA. Singh and Kristian Hiorth. The authors would like to thank Xiaoqing
Zhu and Stefan Holmer for helping with NADA and GCC.
This work was partially funded by the European Community under its This work was partially funded by the European Community under its
Seventh Framework Programme through the Reducing Internet Transport Seventh Framework Programme through the Reducing Internet Transport
Latency (RITE) project (ICT-317700). Latency (RITE) project (ICT-317700).
8. IANA Considerations 8. IANA Considerations
This memo includes no request to IANA. This memo includes no request to IANA.
9. Security Considerations 9. Security Considerations
skipping to change at page 12, line 17 skipping to change at page 12, line 32
RFC 3124, DOI 10.17487/RFC3124, June 2001, RFC 3124, DOI 10.17487/RFC3124, June 2001,
<http://www.rfc-editor.org/info/rfc3124>. <http://www.rfc-editor.org/info/rfc3124>.
[RFC5348] Floyd, S., Handley, M., Padhye, J., and J. Widmer, "TCP [RFC5348] Floyd, S., Handley, M., Padhye, J., and J. Widmer, "TCP
Friendly Rate Control (TFRC): Protocol Specification", Friendly Rate Control (TFRC): Protocol Specification",
RFC 5348, DOI 10.17487/RFC5348, September 2008, RFC 5348, DOI 10.17487/RFC5348, September 2008,
<http://www.rfc-editor.org/info/rfc5348>. <http://www.rfc-editor.org/info/rfc5348>.
10.2. Informative References 10.2. Informative References
[I-D.ietf-rmcat-gcc]
Holmer, S., Lundin, H., Carlucci, G., Cicco, L., and S.
Mascolo, "A Google Congestion Control Algorithm for Real-
Time Communication", draft-ietf-rmcat-gcc-01 (work in
progress), October 2015.
[I-D.ietf-rmcat-nada]
Zhu, X., Pan, R., Ramalho, M., Cruz, S., Jones, P., Fu,
J., D'Aronco, S., and C. Ganzhorn, "NADA: A Unified
Congestion Control Scheme for Real-Time Media",
draft-ietf-rmcat-nada-02 (work in progress), March 2016.
[I-D.ietf-rmcat-sbd]
Hayes, D., Ferlin, S., Welzl, M., and K. Hiorth, "Shared
Bottleneck Detection for Coupled Congestion Control for
RTP Media.", draft-ietf-rmcat-sbd-04 (work in progress),
March 2016.
[I-D.ietf-rtcweb-transports]
Alvestrand, H., "Transports for WebRTC",
draft-ietf-rtcweb-transports-11.txt (work in progress),
January 2016.
[RFC7478] Holmberg, C., Hakansson, S., and G. Eriksson, "Web Real-
Time Communication Use Cases and Requirements", RFC 7478,
DOI 10.17487/RFC7478, March 2015,
<http://www.rfc-editor.org/info/rfc7478>.
[fse] Islam, S., Welzl, M., Gjessing, S., and N. Khademi, [fse] Islam, S., Welzl, M., Gjessing, S., and N. Khademi,
"Coupled Congestion Control for RTP Media", ACM SIGCOMM "Coupled Congestion Control for RTP Media", ACM SIGCOMM
Capacity Sharing Workshop (CSWS 2014); extended version Capacity Sharing Workshop (CSWS 2014) and ACM SIGCOMM CCR
available as a technical report from 44(4) 2014; extended version available as a technical
report from
http://safiquli.at.ifi.uio.no/paper/fse-tech-report.pdf , http://safiquli.at.ifi.uio.no/paper/fse-tech-report.pdf ,
2014. 2014.
[nada] Zhu, X., Pan, R., Ramalho, M., Mena, S., Ganzhorn, C.,
Jones, P., and S. De Aronco, "NADA: A Unified Congestion
Control Scheme for Real-Time Media",
draft-ietf-rmcat-nada-00 (work in progress), April 2015.
[rtcweb-rtp-usage] [rtcweb-rtp-usage]
Perkins, C., Westerlund, M., and J. Ott, "Web Real-Time Perkins, C., Westerlund, M., and J. Ott, "Web Real-Time
Communication (WebRTC): Media Transport and Use of RTP", Communication (WebRTC): Media Transport and Use of RTP",
draft-ietf-rtcweb-rtp-usage-18.txt (work in progress), draft-ietf-rtcweb-rtp-usage-26.txt (work in progress),
October 2014. March 2016.
[rtcweb-usecases]
Holmberg, C., Hakansson, S., and G. Eriksson, "Web Real-
Time Communication Use-cases and Requirements",
draft-ietf-rtcweb-use-cases-and-requirements-14.txt (work
in progress), February 2014.
[sbd] Hayes, D., Ferlin, S., and M. Welzl, "Shared Bottleneck
Detection for Coupled Congestion Control for RTP Media",
draft-ietf-rmcat-sbd-00.txt (work in progress), May 2015.
[transport-multiplex] [transport-multiplex]
Westerlund, M. and C. Perkins, "Multiple RTP Sessions on a Westerlund, M. and C. Perkins, "Multiple RTP Sessions on a
Single Lower-Layer Transport", Single Lower-Layer Transport",
draft-westerlund-avtcore-transport-multiplexing-07.txt draft-westerlund-avtcore-transport-multiplexing-07.txt
(work in progress), October 2013. (work in progress), October 2013.
Appendix A. Scheduling Appendix A. Scheduling
When connections originate from the same host, it would be possible When connections originate from the same host, it would be possible
skipping to change at page 20, line 5 skipping to change at page 20, line 25
3 e) FSE_R(f) = DR(f) = 9.33. 3 e) FSE_R(f) = DR(f) = 9.33.
The resulting FSE looks as follows: The resulting FSE looks as follows:
------------------------------------------- -------------------------------------------
| # | FGI | P | FSE_R | DR | Rate | | # | FGI | P | FSE_R | DR | Rate |
| | | | | | | | | | | | | |
| 2 | 1 | 0.5 | 9.33 | 9.33 | 9.33 | | 2 | 1 | 0.5 | 9.33 | 9.33 | 9.33 |
------------------------------------------- -------------------------------------------
S_CR = 9.33, TLO = 0 S_CR = 9.33, TLO = 0
Appendix C. Change log
C.1. draft-welzl-rmcat-coupled-cc
C.1.1. Changes from -00 to -01
o Added change log.
o Updated the example algorithm and its operation.
C.1.2. Changes from -01 to -02
o Included an active version of the algorithm which is simpler.
o Replaced "greedy flow" with "bulk data transfer" and "non-greedy"
with "application-limited".
o Updated new_CR to CC_R, and CR to FSE_R for better understanding.
C.1.3. Changes from -02 to -03
o Included an active conservative version of the algorithm which
reduces queue growth and packet loss; added a reference to a
technical report that shows these benefits with simulations.
o Moved the passive variant of the algorithm to appendix.
C.1.4. Changes from -03 to -04
o Extended SBD section.
o Added a note about window-based controllers.
C.1.5. Changes from -04 to -05
o Added a section about applying the FSE to specific congestion
control algorithms, with a subsection specifying its use with
NADA.
C.2. draft-ietf-rmcat-coupled-cc
C.2.1. Changes from draft-welzl-rmcat-coupled-cc-05
o Moved scheduling section to the appendix.
C.2.2. Changes from -00 to -01
o Included how to apply the algorithm to GCC.
o Updated variable names of NADA to be in line with the latest
version.
o Added a reference to [I-D.ietf-rtcweb-transports] to make a
connection to the prioritization text there.
Authors' Addresses Authors' Addresses
Safiqul Islam Safiqul Islam
University of Oslo University of Oslo
PO Box 1080 Blindern PO Box 1080 Blindern
Oslo, N-0316 Oslo, N-0316
Norway Norway
Phone: +47 22 84 08 37 Phone: +47 22 84 08 37
Email: safiquli@ifi.uio.no Email: safiquli@ifi.uio.no
 End of changes. 26 change blocks. 
66 lines changed or deleted 166 lines changed or added

This html diff was produced by rfcdiff 1.44. The latest version is available from http://tools.ietf.org/tools/rfcdiff/