Network Working Group F. Baker, Ed.
Internet-Draft Cisco Systems
Obsoletes: 2309 (if approved) March 15, 2013
Intended status: Best Current Practice
Expires: September 16, 2013
IETF Recommendations Regarding Active Queue Management
draft-baker-aqm-recommendation-00
Abstract
This memo presents recommendations to the Internet community
concerning measures to improve and preserve Internet performance. It
presents a strong recommendation for testing, standardization, and
widespread deployment of active queue management in routers, to
improve the performance of today's Internet. It also urges a
concerted effort of research, measurement, and ultimate deployment of
router mechanisms to protect the Internet from flows that are not
sufficiently responsive to congestion notification.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
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This Internet-Draft will expire on September 16, 2013.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 4
2. The Need For Active Queue Management . . . . . . . . . . . . 4
3. Managing Aggressive Flows . . . . . . . . . . . . . . . . . . 7
4. Conclusions and Recommendations . . . . . . . . . . . . . . . 10
4.1. Operational deployments SHOULD implement Active Queue
Management procedures . . . . . . . . . . . . . . . . . . 10
4.2. Signaling to the endpoints of a session . . . . . . . . . 11
4.3. Active Queue Management algorithms deployed SHOULD NOT
require operational tuning . . . . . . . . . . . . . . . 12
4.4. Active Queue Management algorithms deployed SHOULD be
effective on all common Internet traffic . . . . . . . . 12
4.5. TCP and SCTP congestion control algorithms SHOULD
maximize their use of available bandwidth without
incurring loss or undue round trip delay . . . . . . . . 12
4.6. The need for further research . . . . . . . . . . . . . . 12
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13
6. Security Considerations . . . . . . . . . . . . . . . . . . . 13
7. Privacy Considerations . . . . . . . . . . . . . . . . . . . 13
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 13
9. Change Log . . . . . . . . . . . . . . . . . . . . . . . . . 13
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 13
10.1. Normative References . . . . . . . . . . . . . . . . . . 13
10.2. Informative References . . . . . . . . . . . . . . . . . 14
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 16
1. Introduction
The Internet protocol architecture is based on a connectionless end-
to-end packet service using the Internet Protocol, whether IPv4
[RFC0791] or IPv6 [RFC2460]. The advantages of its connectionless
design, flexibility and robustness, have been amply demonstrated.
However, these advantages are not without cost: careful design is
required to provide good service under heavy load. In fact, lack of
attention to the dynamics of packet forwarding can result in severe
service degradation or "Internet meltdown". This phenomenon was
first observed during the early growth phase of the Internet of the
mid 1980s [RFC0896][RFC0970], and is technically called "congestive
collapse".
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The original fix for Internet meltdown was provided by Van Jacobson.
Beginning in 1986, Jacobson developed the congestion avoidance
mechanisms that are now required in TCP implementations [Jacobson88]
[RFC1122]. These mechanisms operate in the hosts to cause TCP
connections to "back off" during congestion. We say that TCP flows
are "responsive" to congestion signals (i.e., marked or dropped
packets) from the network. It is primarily these TCP congestion
avoidance algorithms that prevent the congestive collapse of today's
Internet.
However, that is not the end of the story. Considerable research has
been done on Internet dynamics since 1988, and the Internet has
grown. It has become clear that the TCP congestion avoidance
mechanisms [RFC5681], while necessary and powerful, are not
sufficient to provide good service in all circumstances. Basically,
there is a limit to how much control can be accomplished from the
edges of the network. Some mechanisms are needed in the routers to
complement the endpoint congestion avoidance mechanisms.
It is useful to distinguish between two classes of router algorithms
related to congestion control: "queue management" versus "scheduling"
algorithms. To a rough approximation, queue management algorithms
manage the length of packet queues by marking or dropping packets
when necessary or appropriate, while scheduling algorithms determine
which packet to send next and are used primarily to manage the
allocation of bandwidth among flows. While these two router
mechanisms are closely related, they address rather different
performance issues.
This memo highlights two performance issues. The first issue is the
need for an advanced form of queue management that we call "active
queue management." Section 2 summarizes the benefits that active
queue management can bring. A number of Active Queue Management
procedures are described in the literature, with different
characteristics. This document does not recommend any of them in
particular, but does make recommendations that ideally would affect
the choice of procedure used in a given implementation.
The second issue, discussed in Section 3 of this memo, is the
potential for future congestive collapse of the Internet due to flows
that are unresponsive, or not sufficiently responsive, to congestion
indications. Unfortunately, there is no consensus solution to
controlling congestion caused by such aggressive flows; significant
research and engineering will be required before any solution will be
available. It is imperative that this work be energetically pursued,
to ensure the future stability of the Internet.
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Section 4 concludes the memo with a set of recommendations to the
Internet community concerning these topics.
The discussion in this memo applies to "best-effort" traffic, which
is to say, traffic generated by applications that accept the
occasional loss, duplication, or reordering of traffic in flight. It
is most effective, on timescales of a single RTT or a small number of
RTTs, for elastic traffic [RFC1633], but also impacts real time
traffic generated by adaptive applications.
[RFC2309] resulted from past discussions of end-to-end performance,
Internet congestion, and RED in the End-to-End Research Group of the
Internet Research Task Force (IRTF). This update results from
experience with that and other algorithms, and the Active Queue
Management discussion within the IETF.
1.1. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119].
2. The Need For Active Queue Management
The traditional technique for managing router queue lengths is to set
a maximum length (in terms of packets) for each queue, accept packets
for the queue until the maximum length is reached, then reject (drop)
subsequent incoming packets until the queue decreases because a
packet from the queue has been transmitted. This technique is known
as "tail drop", since the packet that arrived most recently (i.e.,
the one on the tail of the queue) is dropped when the queue is full.
This method has served the Internet well for years, but it has two
important drawbacks.
1. Lock-Out
In some situations tail drop allows a single connection or a few
flows to monopolize queue space, preventing other connections
from getting room in the queue. This "lock-out" phenomenon is
often the result of synchronization or other timing effects.
2. Full Queues
The tail drop discipline allows queues to maintain a full (or,
almost full) status for long periods of time, since tail drop
signals congestion (via a packet drop) only when the queue has
become full. It is important to reduce the steady-state queue
size, and this is perhaps queue management's most important goal.
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The naive assumption might be that there is a simple tradeoff
between delay and throughput, and that the recommendation that
queues be maintained in a "non-full" state essentially translates
to a recommendation that low end-to-end delay is more important
than high throughput. However, this does not take into account
the critical role that packet bursts play in Internet
performance. Even though TCP constrains a flow's window size,
packets often arrive at routers in bursts [Leland94]. If the
queue is full or almost full, an arriving burst will cause
multiple packets to be dropped. This can result in a global
synchronization of flows throttling back, followed by a sustained
period of lowered link utilization, reducing overall throughput.
The point of buffering in the network is to absorb data bursts
and to transmit them during the (hopefully) ensuing bursts of
silence. This is essential to permit the transmission of bursty
data. It should be clear why we would like to have normally-
small queues in routers: we want to have queue capacity to absorb
the bursts. The counter-intuitive result is that maintaining
normally-small queues can result in higher throughput as well as
lower end-to-end delay. In short, queue limits should not
reflect the steady state queues we want maintained in the
network; instead, they should reflect the size of bursts we need
to absorb.
Besides tail drop, two alternative queue disciplines that can be
applied when the queue becomes full are "random drop on full" or
"drop front on full". Under the random drop on full discipline, a
router drops a randomly selected packet from the queue (which can be
an expensive operation, since it naively requires an O(N) walk
through the packet queue) when the queue is full and a new packet
arrives. Under the "drop front on full" discipline [Lakshman96], the
router drops the packet at the front of the queue when the queue is
full and a new packet arrives. Both of these solve the lock-out
problem, but neither solves the full-queues problem described above.
We know in general how to solve the full-queues problem for
"responsive" flows, i.e., those flows that throttle back in response
to congestion notification. In the current Internet, dropped packets
serve as a critical mechanism of congestion notification to end
nodes. The solution to the full-queues problem is for routers to
drop packets before a queue becomes full, so that end nodes can
respond to congestion before buffers overflow. We call such a
proactive approach "active queue management". By dropping packets
before buffers overflow, active queue management allows routers to
control when and how many packets to drop. The next section
introduces RED, an active queue management mechanism that solves both
problems listed above (given responsive flows).
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In summary, an active queue management mechanism can provide the
following advantages for responsive flows.
1. Reduce number of packets dropped in routers
Packet bursts are an unavoidable aspect of packet networks
[Willinger95]. If all the queue space in a router is already
committed to "steady state" traffic or if the buffer space is
inadequate, then the router will have no ability to buffer
bursts. By keeping the average queue size small, active queue
management will provide greater capacity to absorb naturally-
occurring bursts without dropping packets.
Furthermore, without active queue management, more packets will
be dropped when a queue does overflow. This is undesirable for
several reasons. First, with a shared queue and the tail drop
discipline, an unnecessary global synchronization of flows
cutting back can result in lowered average link utilization, and
hence lowered network throughput. Second, TCP recovers with more
difficulty from a burst of packet drops than from a single packet
drop. Third, unnecessary packet drops represent a possible waste
of bandwidth on the way to the drop point.
We note that while Active Queue Management can manage queue
lengths and reduce end- to-end latency even in the absence of
end-to-end congestion control, Active Queue Management will be
able to reduce packet dropping only in an environment that
continues to be dominated by end-to-end congestion control.
2. Provide lower-delay interactive service
By keeping the average queue size small, queue management will
reduce the delays seen by flows. This is particularly important
for interactive applications such as short Web transfers, Telnet
traffic, or interactive audio-video sessions, whose subjective
(and objective) performance is better when the end-to-end delay
is low.
3. Avoid lock-out behavior
Active queue management can prevent lock-out behavior by ensuring
that there will almost always be a buffer available for an
incoming packet. For the same reason, active queue management
can prevent a router bias against low bandwidth but highly bursty
flows.
It is clear that lock-out is undesirable because it constitutes a
gross unfairness among groups of flows. However, we stop short
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of calling this benefit "increased fairness", because general
fairness among flows requires per-flow state, which is not
provided by queue management. For example, in a router using
queue management but only FIFO scheduling, two TCP flows may
receive very different bandwidths simply because they have
different round-trip times [Floyd91], and a flow that does not
use congestion control may receive more bandwidth than a flow
that does. Per-flow state to achieve general fairness might be
maintained by a per-flow scheduling algorithm such as Fair
Queueing (FQ) [Demers90], or a class-based scheduling algorithm
such as CBQ [Floyd95], for example.
On the other hand, active queue management is needed even for
routers that use per-flow scheduling algorithms such as FQ or
class-based scheduling algorithms such as CBQ. This is because
per-flow scheduling algorithms by themselves do nothing to
control the overall queue size or the size of individual queues.
Active queue management is needed to control the overall average
queue sizes, so that arriving bursts can be accommodated without
dropping packets. In addition, active queue management should be
used to control the queue size for each individual flow or class,
so that they do not experience unnecessarily high delays.
Therefore, active queue management should be applied across the
classes or flows as well as within each class or flow.
In short, scheduling algorithms and queue management should be
seen as complementary, not as replacements for each other.
3. Managing Aggressive Flows
One of the keys to the success of the Internet has been the
congestion avoidance mechanisms of TCP. Because TCP "backs off"
during congestion, a large number of TCP connections can share a
single, congested link in such a way that bandwidth is shared
reasonably equitably among similarly situated flows. The equitable
sharing of bandwidth among flows depends on the fact that all flows
are running basically the same congestion avoidance algorithms,
conformant with the current TCP specification [RFC1122].
Flows that behaves under congestion like a flow produced by a
conformant TCP have come to be called "TCP Friendly" [RFC5348]. A
TCP Friendly flow is responsive to congestion notification, and in
steady-state it uses no more bandwidth than a conformant TCP running
under comparable conditions (drop rate, RTT, MTU, etc.)
It is convenient to divide flows into three classes: (1) TCP Friendly
flows, (2) unresponsive flows, i.e., flows that do not slow down when
congestion occurs, and (3) flows that are responsive but are not TCP
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Friendly. The last two classes contain more aggressive flows that
pose significant threats to Internet performance, as we will now
discuss.
o Non-Responsive Flows
There is a growing set of UDP-based applications whose congestion
avoidance algorithms are inadequate or nonexistent (i.e, the flow
does not throttle back upon receipt of congestion notification).
Such UDP applications include streaming applications like packet
voice and video, and also multicast bulk data transport [SRM96].
If no action is taken, such unresponsive flows could lead to a new
congestive collapse.
In general, all UDP-based streaming applications should
incorporate effective congestion avoidance mechanisms. For
example, recent research has shown the possibility of
incorporating congestion avoidance mechanisms such as Receiver-
driven Layered Multicast (RLM) within UDP-based streaming
applications such as packet video [McCanne96] [Bolot94]. Further
research and development on ways to accomplish congestion
avoidance for streaming applications will be very important.
However, it will also be important for the network to be able to
protect itself against unresponsive flows, and mechanisms to
accomplish this must be developed and deployed. Deployment of
such mechanisms would provide incentive for every streaming
application to become responsive by incorporating its own
congestion control.
o Non-TCP-Friendly Transport Protocols
The second threat is posed by transport protocol implementations
that are responsive to congestion notification but, either
deliberately or through faulty implementations, are not TCP
Friendly. Such applications can grab an unfair share of the
network bandwidth.
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For example, the popularity of the Internet has caused a
proliferation in the number of TCP implementations. Some of these
may fail to implement the TCP congestion avoidance mechanisms
correctly because of poor implementation. Others may deliberately
be implemented with congestion avoidance algorithms that are more
aggressive in their use of bandwidth than other TCP
implementations; this would allow a vendor to claim to have a
"faster TCP". The logical consequence of such implementations
would be a spiral of increasingly aggressive TCP implementations,
leading back to the point where there is effectively no congestion
avoidance and the Internet is chronically congested.
Another example of such flows is RTP/UDP video data flows in which
the application uses an adaptive codec. Such data flows are not
responsive to congestion signals in a timeframe comparable to a
small number of end-to-end transmission delays. However, over a
longer timescale, perhaps seconds in duration, they will moderate
their speed, or will increase their speed if they determine
bandwidth to be available.
Note that there is a well-known way to achieve more aggressive TCP
performance without even changing TCP: open multiple connections
to the same place, as has been done in multiple Web browsers and
in peer-to-peer applications such as BitTorrent.
The projected increase in more aggressive flows of both these
classes, as a fraction of total Internet traffic, clearly poses a
threat to the future Internet. There is an urgent need for
measurements of current conditions and for further research into the
various ways of managing such flows. There are many difficult issues
in identifying and isolating unresponsive or non-TCP-Friendly flows
at an acceptable router overhead cost. Finally, there is little
measurement or simulation evidence available about the rate at which
these threats are likely to be realized, or about the expected
benefit of router algorithms for managing such flows.
There is an issue about the appropriate granularity of a "flow".
There are a few "natural" answers: 1) a TCP or UDP connection (source
address/port, destination address/port); 2) a source/destination host
pair; 3) a given source host or a given destination host. We would
guess that the source/destination host pair gives the most
appropriate granularity in many circumstances. However, it is
possible that different vendors/providers could set different
granularities for defining a flow (as a way of "distinguishing"
themselves from one another), or that different granularities could
be chosen for different places in the network. It may be the case
that the granularity is less important than the fact that we are
dealing with more unresponsive flows at *some* granularity. The
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granularity of flows for congestion management is, at least in part,
a policy question that needs to be addressed in the wider IETF
community.
4. Conclusions and Recommendations
The IRTF, in developing [RFC2309], and the IETF in subsequent
discussion, has developed a set of specific recommendations regarding
the implementation and operational use of Active Queue Management
procedures. These include:
1. Internet routers SHOULD implement some active queue management
mechanism to manage queue lengths, reduce end-to-end latency,
reduce packet dropping, and avoid lock-out phenomena within the
Internet.
2. Deployed Active Queue Management SHOULD use ECN as well as loss
in signaling congestion to endpoints.
3. Active Queue Management algorithms deployed SHOULD NOT require
operational (especially manual) configuration or tuning.
4. Active Queue Management algorithms deployed SHOULD be effective
on all common Internet traffic, including traffic that uses TCP,
SCTP, UDP, and DCCP as transports.
5. TCP and SCTP congestion control algorithms SHOULD maximize their
use of available bandwidth without incurring loss or undue round
trip delay when possible.
6. It is urgent to continue research, engineering, and measurement
efforts contributing to the design of mechanisms to deal with
flows that are unresponsive to congestion notification or are
responsive but more aggressive than TCP.
These recommendations are expressed using the word "SHOULD". This is
in recognition that there may be use cases unenvisaged in this
document in which the recommendation dos not apply. However, care
should be taken in concluding that one's use case falls in that
category; during the life of the Internet, such use cases have been
rarely if ever observed and reported on. To the contrary, available
research [Papagiannaki] says that even high speed links in network
cores that are normally very stable in depth and behavior experience
occasional issues that need moderation.
4.1. Operational deployments SHOULD implement Active Queue Management
procedures
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In short, Active Queue Management procedures are designed to minimize
delay induced in the network by queues which have filled as a result
of host behavior. Marking and loss behaviors signal to the senders
of data that network buffers are becoming unnecessarily full, and
they would do well to moderate their behavior.
4.2. Signaling to the endpoints of a session
Means of signaling to an endpoint regarding its effect on the network
and how it might consider adapting include, at least:
o Delaying data segments in flight, such as in a queue, which
affects Ack Clocking and as a result the transmission of new data.
o Marking traffic, such as using Explicit Congestion
Control[RFC3168] [RFC4301] [RFC4774] [RFC6040]
o Dropping traffic in transit.
The use of advanced scheduling mechanisms, such as priority queuing,
classful queuing, and fair queuing, is often effective in networks to
help a network to serve the needs of an application. It can be used
to manage traffic passing a choke point. This is discussed in
[RFC2474] and [RFC2475]. They are used operationally when an
operator considers it important to do so.
Loss has two effects. It protects the network, which is the primary
reason the network imposes it. Its use as a signal to TCP or SCTP is
a pragmatic heuristic; "when the network discards a message in
flight, it may imply the presence of faulty equipment or media in a
path, and it may imply the presence of congestion. Presume the
latter." However, it also has an effect on the efficiency of the
data flow. The data in question must be retransmitted, or its
absence must otherwise be adapted to by the application in question,
which implies at least inefficient use of available bandwidth and may
affect other data flows. Hence, loss is not entirely positive; it is
a necessary evil.
Explicit Congestion Control, however, communicates information about
network congestion that is assuredly about congestion, and avoids the
unintended consequences of loss.
Hence, network communication to the host regarding the moderation of
its traffic flow SHOULD use an AQM algorithm to determine which
packets it should affect, and then implement that effect by marking
ECN-capable traffic "Congestion Experienced (CE)" or dropping non-
ECN-capable traffic.
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Due to the possibility of abuse, the queue must also impose an upper
bound, so that even ECN-capable traffic experiences tail-drop if
necessary; this possibility, while equipment must design for the end
case, should in theory be very uncommon.
4.3. Active Queue Management algorithms deployed SHOULD NOT require
operational tuning
A number of algorithms have been proposed. Many require some form of
tuning or initial condition, which makes them difficult to use
operationally. Hence, self-tuning algorithms are to be preferred.
4.4. Active Queue Management algorithms deployed SHOULD be effective on
all common Internet traffic
Active Queue Management algorithms often target TCP [RFC0793], as it
is by far the predominant transport in the Internet today. However,
we have significant use of UDP [RFC0768] in voice and video services,
and find utility in SCTP [RFC4960] and DCCP [RFC4340]. Hence, Active
Queue Management algorithms that are effective with all of those
transports and the applications that use them are to be preferred.
4.5. TCP and SCTP congestion control algorithms SHOULD maximize their
use of available bandwidth without incurring loss or undue round
trip delay
The terms "knee" and "cliff" area defined by [Jain94]. They
respectively refer to the minimum and maximum values of the effective
window that have the effect of maximizing transmission rate in a
congestion control algorithm such as is used by TCP or SCTP. For the
sender of data, exceeding the cliff is ineffective, as it (by
definition) induces loss; operating at a point close to the cliff has
a negative impact on other traffic and applications, triggering
operator activities such as discussed in [RFC6057].
Operating below the knee is also ineffective, as it fails to use
available network capacity. If the objective is to deliver data from
its source to its recipient in the least possible time, as a result,
the behavior of any TCP/SCTP congestion control algorithm SHOULD be
to seek and use effective window values at or above the knee and well
below the cliff.
4.6. The need for further research
[RFC2309] called for, as its second recommendation, further research
in the interaction between network queues and host applications, and
the means of signaling between them. This research occurred, and we
as a community have learned a lot. However, we are not done. An
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obvious example in 2013 is in the use of Map/Reduce applications in
data centers; do we need to extend our taxonomy of TCP/SCTP sessions
to include not only "mice" and "elephants", but lemmings - flash
crowds of "mice" that the network inadvertently tries to signal to as
if they were elephant flows, resulting in head of line blocking in
data center applications?
Hence, this document reiterates the call: we need continuing research
as applications develop.
5. IANA Considerations
This memo asks the IANA for no new parameters.
6. Security Considerations
While security is a very important issue, it is largely orthogonal to
the performance issues discussed in this memo. We note, however,
that denial-of-service attacks may create unresponsive traffic flows
that are indistinguishable from flows from normal high-bandwidth
isochronous applications, and the mechanism suggested in The
recommendation in support of ongoing research will be equally
applicable to such attacks.
7. Privacy Considerations
This document, by itself, presents no new privacy issues.
8. Acknowledgements
The original recommendation in [RFC2309] was written by the End-to-
End Research Group, which is to say Bob Braden, Dave Clark, Jon
Crowcroft, Bruce Davie, Steve Deering, Deborah Estrin, Sally Floyd,
Van Jacobson, Greg Minshall, Craig Partridge, Larry Peterson, KK
Ramakrishnan, Scott Shenker, John Wroclawski, and Lixia Zhang. This
is an edited version of that document, with much of its text and
arguments unchanged.
9. Change Log
Initial Version: March 2013
10. References
10.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
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[RFC3168] Ramakrishnan, K., Floyd, S., and D. Black, "The Addition
of Explicit Congestion Notification (ECN) to IP", RFC
3168, September 2001.
[RFC4301] Kent, S. and K. Seo, "Security Architecture for the
Internet Protocol", RFC 4301, December 2005.
[RFC4774] Floyd, S., "Specifying Alternate Semantics for the
Explicit Congestion Notification (ECN) Field", BCP 124,
RFC 4774, November 2006.
[RFC6040] Briscoe, B., "Tunnelling of Explicit Congestion
Notification", RFC 6040, November 2010.
10.2. Informative References
[Bolot94] Bolot, JC., Turletti, T., and T. Wakeman, "Scalable
Feedback Control for Multicast Video Distribution in the
Internet", SIGCOMM Symposium proceedings on Communications
architectures and protocols , August 1994.
[Demers90]
Demers, A., Keshav, S., and S. Shenker, "Analysis and
Simulation of a Fair Queueing Algorithm, Internetworking:
Research and Experience", SIGCOMM Symposium proceedings on
Communications architectures and protocols , 1990.
[Floyd91] Floyd, S., "Connections with Multiple Congested Gateways
in Packet-Switched Networks Part 1: One-way Traffic.",
Computer Communications Review , October 1991.
[Floyd95] Floyd, S. and V. Jacobson, "Link-sharing and Resource
Management Models for Packet Networks", IEEE/ACM
Transactions on Networking , August 1995.
[Jacobson88]
Jacobson, V., "Congestion Avoidance and Control", SIGCOMM
Symposium proceedings on Communications architectures and
protocols , August 1988.
[Jain94] Jain, Raj., Ramakrishnan, KK., and Chiu. Dah-Ming,
"Congestion avoidance scheme for computer networks", US
Patent Office 5377327, December 1994.
[Lakshman96]
Lakshman, TV., Neidhardt, A., and T. Ott, "The Drop From
Front Strategy in TCP Over ATM and Its Interworking with
Other Control Features", IEEE Infocomm , 1996.
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[Leland94]
Leland, W., Taqqu, M., Willinger, W., and D. Wilson, "On
the Self-Similar Nature of Ethernet Traffic (Extended
Version)", IEEE/ACM Transactions on Networking , February
1994.
[McCanne96]
McCanne, S., Jacobson, V., and M. Vetterli, "Receiver-
driven Layered Multicast", SIGCOMM Symposium proceedings
on Communications architectures and protocols , August
1996.
[Papagiannaki]
Sprint ATL, KAIST, University of Minnesota, Sprint ATL,
Intel Research, "Analysis of Point-To-Point Packet Delay
In an Operational Network", IEEE Infocom 2004, March 2004,
<http://www.ieee-infocom.org/2004/Papers/37_4.PDF>.
[RFC0768] Postel, J., "User Datagram Protocol", STD 6, RFC 768,
August 1980.
[RFC0791] Postel, J., "Internet Protocol", STD 5, RFC 791, September
1981.
[RFC0793] Postel, J., "Transmission Control Protocol", STD 7, RFC
793, September 1981.
[RFC0896] Nagle, J., "Congestion control in IP/TCP internetworks",
RFC 896, January 1984.
[RFC0970] Nagle, J., "On packet switches with infinite storage", RFC
970, December 1985.
[RFC1122] Braden, R., "Requirements for Internet Hosts -
Communication Layers", STD 3, RFC 1122, October 1989.
[RFC1633] Braden, B., Clark, D., and S. Shenker, "Integrated
Services in the Internet Architecture: an Overview", RFC
1633, June 1994.
[RFC2309] Braden, B., Clark, D.D., Crowcroft, J., Davie, B.,
Deering, S., Estrin, D., Floyd, S., Jacobson, V.,
Minshall, G., Partridge, C., Peterson, L., Ramakrishnan,
K.K., Shenker, S., Wroclawski, J., and L. Zhang,
"Recommendations on Queue Management and Congestion
Avoidance in the Internet", RFC 2309, April 1998.
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[RFC2460] Deering, S.E. and R.M. Hinden, "Internet Protocol, Version
6 (IPv6) Specification", RFC 2460, December 1998.
[RFC2474] Nichols, K., Blake, S., Baker, F., and D.L. Black,
"Definition of the Differentiated Services Field (DS
Field) in the IPv4 and IPv6 Headers", RFC 2474, December
1998.
[RFC2475] Blake, S., Black, D.L., Carlson, M.A., Davies, E., Wang,
Z., and W. Weiss, "An Architecture for Differentiated
Services", RFC 2475, December 1998.
[RFC4340] Kohler, E., Handley, M., and S. Floyd, "Datagram
Congestion Control Protocol (DCCP)", RFC 4340, March 2006.
[RFC4960] Stewart, R., "Stream Control Transmission Protocol", RFC
4960, September 2007.
[RFC5348] Floyd, S., Handley, M., Padhye, J., and J. Widmer, "TCP
Friendly Rate Control (TFRC): Protocol Specification", RFC
5348, September 2008.
[RFC5681] Allman, M., Paxson, V., and E. Blanton, "TCP Congestion
Control", RFC 5681, September 2009.
[RFC6057] Bastian, C., Klieber, T., Livingood, J., Mills, J., and R.
Woundy, "Comcast's Protocol-Agnostic Congestion Management
System", RFC 6057, December 2010.
[SRM96] Floyd, S., Jacobson, V., McCanne, S., Liu, C., and L.
Zhang, "A Reliable Multicast Framework for Light-weight
Sessions and Application Level Framing", SIGCOMM Symposium
proceedings on Communications architectures and protocols
, 1996.
[Willinger95]
Willinger, W., Taqqu, M., Sherman, R., Wilson, D., and V.
Jacobson, "Self-Similarity Through High-Variability:
Statistical Analysis of Ethernet LAN Traffic at the Source
Level", SIGCOMM Symposium proceedings on Communications
architectures and protocols , August 1995.
Author's Address
Baker Expires September 16, 2013 [Page 16]
Internet-Draft Active Queue Management Recommendations March 2013
Fred Baker (editor)
Cisco Systems
Santa Barbara, California 93117
USA
Email: fred@cisco.com
Baker Expires September 16, 2013 [Page 17]