Transient behaviors of TCP-friendly congestion control protocols (2001)

by Yang R Yang, Min S Kim, Simon S Lam
Venue:In Proceedings of the Twentieth Annual Joint Conference of the IEEE Computer and Communications Societies (INFOCOM 2001
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General AIMD Congestion Control

by Y. Richard Yang, Simon S. Lam , 2000
"... Instead of the increase-by-one decrease-to-half strategy used in TCP Reno for congestion window adjustment, we consider the general case such that the increase value and decrease ratio are parameters. That is, in the congestion avoidance state, the window size is increased by ff per window of pac ..."
Abstract - Cited by 144 (6 self) - Add to MetaCart
Instead of the increase-by-one decrease-to-half strategy used in TCP Reno for congestion window adjustment, we consider the general case such that the increase value and decrease ratio are parameters. That is, in the congestion avoidance state, the window size is increased by ff per window of packets acknowledged and it is decreased to fi of the current value when there is congestion indication. We refer to this window adjustment strategy as general additive increase multiplicative decrease (GAIMD). We present the (mean) sending rate of a GAIMD flow as a function of ff, fi, loss rate, mean roundtrip time, mean timeout value, and the number of packets acknowledged by each ACK. We conducted extensive experiments to validate this sending rate formula. We found the formula to be quite accurate for a loss rate of up to 20%. We also present in this paper a simple relationship between ff and fi for a GAIMD flow to be TCP-friendly, that is, for the GAIMD flow to have approximately the same sending rate as a TCP flow under the same path conditions.
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Dynamic Behavior of Slowly-Responsive Congestion Control Algorithm

by Deepak Bansal , Hari Balakrishnan , Sally Floyd , Scott Shenker - In Proceedings of ACM SIGCOMM 2001 , 2001
"... Abstract The recently developed notion of TCP-compatibility has led to a number of proposals for alternative congestion control algorithms whose long-term throughput as a function of a steady-state loss rate is similar to that of TCP. Motivated by the needs of some streaming and multicast applicati ..."
Abstract - Cited by 103 (10 self) - Add to MetaCart
Abstract The recently developed notion of TCP-compatibility has led to a number of proposals for alternative congestion control algorithms whose long-term throughput as a function of a steady-state loss rate is similar to that of TCP. Motivated by the needs of some streaming and multicast applications, these algorithms seem poised to take the current TCP-dominated Internet to an Internet where many congestion control algorithms co-exist. An important characteristic of these alternative algorithms is that they are slowly-responsive, refraining from reacting as drastically as TCP to a single packet loss. However, the TCP-compatibility criteria explored so far in the literature considers only the static condition of a fixed loss rate. This paper investigates the behavior of slowly-responsive, TCPcompatible congestion control algorithms under more realistic dynamic network conditions, addressing the fundamental question of whether these algorithms are safe to deploy in the public Internet. We study persistent loss rates, long-and short-term fairness properties, bottleneck link utilization, and smoothness of transmission rates.

Improving Throughput and Maintaining Fairness Using Parallel TCP

by Thomas J. Hacker, Brian D. Noble, Brian D. Athey - IEEE INFOCOM , 2004
"... Applications that require good network performance often use parallel TCP streams and TCP modifications to improve the effectiveness of TCP. If the network bottleneck is fully utilized, this approach boosts throughput by unfairly stealing bandwidth from competing TCP streams. Improving the effective ..."
Abstract - Cited by 57 (4 self) - Add to MetaCart
Applications that require good network performance often use parallel TCP streams and TCP modifications to improve the effectiveness of TCP. If the network bottleneck is fully utilized, this approach boosts throughput by unfairly stealing bandwidth from competing TCP streams. Improving the effectiveness of TCP is easy, but improving effectiveness while maintaining fairness is difficult. In this paper, we describe an approach we implemented that uses a long virtual round trip time in combination with parallel TCP streams to improve effectiveness on underutilized networks. Our approach prioritizes fairness at the expense of effectiveness when the network is fully utilized. We compared our approach with standard parallel TCP over a wide-area network, and found that our approach preserves effectiveness and is fairer to competing traffic than standard parallel TCP.
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TCP-Real: Receiver-oriented Congestion Control

by V. Tsaoussidis, C. Zhang , 2002
"... We introduce a receiver-oriented approach to congestion control, demonstrated by an experimental protocol, TCP-Real. The protocol allows for a measurement-based transmission strategy, which complements the "blind " increase/decrease window adjustments. Owing to its design, the pr ..."
Abstract - Cited by 43 (25 self) - Add to MetaCart
We introduce a receiver-oriented approach to congestion control, demonstrated by an experimental protocol, TCP-Real. The protocol allows for a measurement-based transmission strategy, which complements the "blind " increase/decrease window adjustments. Owing to its design, the protocol displays an inherent property to produce comprehensive dynamics in heterogeneous environments with wired or wireless networks and delay-sensitive or-tolerant applications. TCP-Real controls congestion as standard TCP does. However, its receiver-oriented nature and its “wave” communication pattern allow for two amending mechanisms: (i) Congestion avoidance, which reduces unnecessary transmission gaps that hurt the performance of time-constrained applications, and (ii) Advanced error detection and classification, which designates recovery tactics responsive to the nature of the errors, thereby enhancing the protocol performance over wireless links or asymmetric paths. We detail the protocol mechanisms and specification and we report extensively on the comparative fairness and efficiency evaluation of standard TCP, TCP-Real, and TCP-friendly protocols for both delay-tolerant and-sensitive applications and in both wired and wireless networks.

Limitations of equation-based congestion control

by Injong Rhee, Lisong Xu - in Proc. ACM SIGCOMM 2005 , 2005
"... We study limitations of an equation-based congestion control protocol, called TFRC (TCP Friendly Rate Control). It examines how the three main factors that determine TFRC throughput, namely, the TCP friendly equation, loss event rate estimation and delay estimation, can influence the longterm throug ..."
Abstract - Cited by 34 (1 self) - Add to MetaCart
We study limitations of an equation-based congestion control protocol, called TFRC (TCP Friendly Rate Control). It examines how the three main factors that determine TFRC throughput, namely, the TCP friendly equation, loss event rate estimation and delay estimation, can influence the longterm throughput imbalance between TFRC and TCP. Especially, we show that different sending rates of competing flows cause these flows to experience different loss event rates. There are several fundamental reasons why TFRC and TCP flows have different average sending rates, from the first place. Earlier work shows that the convexity of the TCP friendly equation used in TFRC causes the sending rate difference. We report two additional reasons in this paper: (1) the convexity of 1/x where x is a loss event period and (2) different RTO (retransmission timeout period) estimations of TCP and TFRC. These factors can be the reasons for TCP and TFRC to experience initially different sending rates. But we find that the loss event rate difference due to the differing sending rates greatly amplifies the initial throughput difference; in some extreme cases, TFRC uses around 20 times more, or sometimes 10 times less, bandwidth than TCP.
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A Spectrum of TCP-friendly Window-based Congestion Control Algorithms

by Shudong Jin, Liang Guo, Ibrahim Matta, Azer Bestavros - IEEE/ACM Transactions on Networking , 2001
"... The increasing diversity of Internet application requirements has spurred recent interest in transport protocols with flexible transmission controls. In window-based congestion control schemes, increase rules determine how to probe available bandwidth, whereas decrease rules determine how to back ..."
Abstract - Cited by 31 (5 self) - Add to MetaCart
The increasing diversity of Internet application requirements has spurred recent interest in transport protocols with flexible transmission controls. In window-based congestion control schemes, increase rules determine how to probe available bandwidth, whereas decrease rules determine how to back off when losses due to congestion are detected. The control rules are parameterized so as to ensure that the resulting protocol is TCP-friendly in terms of the relationship between throughput and loss rate. This paper presents a comprehensive study of a new spectrum of window-based congestion controls, which are TCP-friendly as well as TCP-compatible under RED.
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The Dynamics of Responsiveness and Smoothness in Heterogeneous Networks

by Vassilis Tsaoussidis, Senior Member, Chi Zhang - IEEE Journal on Selected Areas in Communications (JSAC , 2005
"... protocols, including transmission control protocol (TCP), TCP-friendly, and a new generation of rate-based protocols, attempt to control the tradeoff of responsiveness and smoothness. Traditionally, smoothness has not been a main concern since it does not impact the performance of regular Internet a ..."
Abstract - Cited by 27 (23 self) - Add to MetaCart
protocols, including transmission control protocol (TCP), TCP-friendly, and a new generation of rate-based protocols, attempt to control the tradeoff of responsiveness and smoothness. Traditionally, smoothness has not been a main concern since it does not impact the performance of regular Internet applications such as the Web, FTP, or e-mail. However, multimedia-driven protocols attempt to favor smoothness at the cost of responsiveness. In general, smoothness and responsiveness constitute a tradeoff; however, we uncover undesirable dynamics of the protocols in the context of wireless/mobile networks with high-error rate or frequent handoffs: low responsiveness is not counterbalanced by gains in smoothness, but instead, produces a conservative behavior that degrades protocol performance with both delay-tolerant and-sensitive applications. Based on our observations, as well as on further analysis of the impact of the bottleneck queue on channel utilization, we seek an alternative strategy for smooth window adjustments. We introduce a new parameter, which implements a congestion avoidance tactic and reaches better smoothness without damaging responsiveness. Index Terms—Congestion control, fairness, transmission control protocol (TCP)-friendly protocols. I.
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MediaAnd TCP-friendly congestion control for scalable video streams

by Jinyao Yan, Kostas Katrinis, Martin May, Bernhard Plattner - in IEEE Trans. Multimedia , 2006
"... Abstract—This paper presents a media- and TCP-friendly ratebased congestion control algorithm (MTFRCC) for scalable video streaming in the Internet. The algorithm integrates two new techniques: i) a utility-based model using the rate-distortion function as the application utility measure for optimiz ..."
Abstract - Cited by 27 (0 self) - Add to MetaCart
Abstract—This paper presents a media- and TCP-friendly ratebased congestion control algorithm (MTFRCC) for scalable video streaming in the Internet. The algorithm integrates two new techniques: i) a utility-based model using the rate-distortion function as the application utility measure for optimizing the overall video quality; and ii) a two-timescale approach of rate averages (longterm and short-term) to satisfy both media and TCP-friendliness. We evaluate our algorithm through simulation and compare the results against the TCP-friendly rate control (TFRC) algorithm. For assessment, we consider five criteria: TCP fairness, responsiveness, aggressiveness, overall video quality, and smoothness of the resulting bit rate. Our simulation results manifest that MTFRCC performs better than TFRC for various congestion levels, including an improvement of the overall video quality. Index Terms—Algorithms, Internet, multimedia communication, optimal control.
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Effect of Vertical Handovers on Performance of TCP-Friendly Rate Control

by Andrei Gurtov, Jouni Korhonen, Teliasonera Finland - ACM Mobile Computing and Communications Review , 2004
"... this paper, we evaluate performance of TFRC during handovers between GPRS, WLAN, and UMTS.We measure behavior of TFRC and TCP flows in a testbed implementing vertical handovers using Mobile IP. To verify our testbed measurements and to study the effect of changes in path characteristics, we use an i ..."
Abstract - Cited by 23 (0 self) - Add to MetaCart
this paper, we evaluate performance of TFRC during handovers between GPRS, WLAN, and UMTS.We measure behavior of TFRC and TCP flows in a testbed implementing vertical handovers using Mobile IP. To verify our testbed measurements and to study the effect of changes in path characteristics, we use an ideal handover model in the ns-2 simulator [40]. Essentially, an ideal handover is represented by a step change in the bottleneck link bandwidth, latency, and buffer size, as if a smooth handover with packet forwarding were implemented [7]. Throughput, aggressiveness, responsiveness, and fairness of TFRC are evaluated. We show that there are significant problems with using TFRC in the presence of vertical handovers. In particular, over a fast link TFRC receives only a fraction of TCP throughput, while over a slow link TFRC can starve concurrent TCP flows after a handover. Two proposals based on overbuffering and an explicit handover notification are demonstrated to be effective solutions to these problems
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Optimal Distribution Tree for Internet Streaming Media

by Min Sik Kim, Kim Simon, Simon S. Lam, Dong-young Lee , 2003
"... Internet radio and television stations require significant bandwidth to support delivery of high quality audio and video streams to a large number of receivers. IP multicast is an appropriate delivery model for these applications. However, widespread deployment of IP multicast on the Internet is ..."
Abstract - Cited by 23 (3 self) - Add to MetaCart
Internet radio and television stations require significant bandwidth to support delivery of high quality audio and video streams to a large number of receivers. IP multicast is an appropriate delivery model for these applications. However, widespread deployment of IP multicast on the Internet is unlikely in the near future. An alternative is to build a multicast tree in the application layer. Previous studies have addressed tree construction in the application layer. However, most of them focus on reducing delay.