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2005, Lecture Notes in Computer Science
Current TCP congestion control can be inefficient and unstable in high-speed wide area networks due to its slow response with a large congestion window. Several congestion control proposals have already been suggested to solve these problems. In this paper, we propose a new variant of TCP for a high-speed network, which combines delay-based congestion control with loss-based congestion control. Our simulation results show that the proposed scheme performs better than the existing high-speed TCP protocols in terms of fairness, stability, and scalability, while providing TCP friendliness at the same time.
The demand for fast transfer of large volumes of data, and the deployment of the network infrastructures is ever increasing. However, the dominant transport protocol of today, TCP, does not meet this demand because it favors reliability over timeliness and fails to fully utilize the network capacity due to limitations of its conservative congestion control algorithm. The slow response of TCP in fast long distance networks leaves sizeable unused bandwidth in such networks. A large variety of TCP variants have been proposed to improve the connection's throughput by adopting more aggressive congestion control algorithms. Some of the flavors of TCP congestion control are loss-based, high-speed TCP congestion control algorithms that uses packet losses as an indication of congestion; delay-based TCP congestion control that emphasizes packet delay rather than packet loss as a signal to determine the rate at which to send packets. Some efforts combine the features of loss-based and delay-based algorithms to achieve fair bandwidth allocation and fairness among flows. A comparative analysis between different flavors of TCP congestion control namely Standard TCP congestion control (TCP Reno), loss-based TCP congestion control (HighSpeed TCP, Scalable TCP, CUBIC TCP), delay-based TCP congestion control (TCP Vegas) and mixed loss-delay based TCP congestion control (Compound TCP) is presented here in terns of congestion window verses elapsed time after the connection is established.
asiafi.net
The Transport Control Protocol (TCP) has contributed to the tremendous success of the Internet but it also includes many problems which are becoming more and more significant as the network grows. Although numerous congestion algorithms have been proposed to improve the performance of TCP in heterogeneous networks, designing a congestion algorithm that could achieve high utilization, ensure fairness and maintain stability remains a great challenge. In this paper, we propose a novel congestion control algorithm named FTCP to tackle these challenges. FTCP is trying to solve TCP's challenges by adjusting its initial congestion window (cwnd) and cwnd updating rate with the aids of measuring the bottleneck queue length. To evaluate the performance of our algorithm, extensive experiments have been performed using network simulation tool. Experimental results prove that FTCP has obvious advantages in efficiency, fairness, TCP friendliness and stability comparing to the existing stateof-the-art congestion control algorithms.
… . Mathematics and Computers in Science and …, 2009
The demands for fast transfer of large volumes of data, and the deployment of the network infrastructures to support the demand are ever increasing. However, the dominant transport protocol of today, TCP, does not meet this demand because it favors reliability over timeliness and fails to fully utilize the network capacity due to limitations of its conservative congestion control algorithm. The slow response of TCP in fast long distance networks leaves sizeable unused bandwidth in such networks. Some works have been proposed to improve the connection's throughput by adopting more aggressive TCP congestion control algorithms. The existing loss-based, high-speed TCP congestion control algorithms are highly aggressive to satisfy the efficiency requirement, however this aggressiveness causes severe TCP unfairness. A comparative analysis of TCP Reno with three lossbased, high-speed TCP congestion control algorithms namely, HSTCP, STCP, and CUBIC-TCP is presented in this paper using default parameters of these algorithms for different network topologies.
Performance Evaluation, 2008
We introduce a new congestion control algorithm, called TCP-Illinois, which has many desirable properties for implementation in (very) high-speed networks. TCP-Illinois is a sender side protocol, which modifies the AIMD algorithm of the standard TCP (Reno, NewReno or SACK) by adjusting the increment/decrement amounts based on delay information. By using both loss and delay as congestion signals, TCP-Illinois achieves a better throughput than the standard TCP for high-speed networks. To study its fairness and stability properties, we extend recently developed stochastic matrix models of TCP to accommodate window size backoff probabilities that are proportional to arrival rates when the network is congested. Using this model, TCP-Illinois is shown to allocate the network resource fairly as in the standard TCP. In addition, TCP-Illinois is shown to be compatible with the standard TCP when implemented in today's networks, and is shown to provide the right incentive for transition to the new protocol. We finally perform ns-2 simulations to validate its properties and demonstrate its performance.
TCP or Transmission Control Protocol represents one of the prevailing ''languages'' of the Internet Protocol Suite, complementing the Internet Protocol (IP), and therefore the entire suite is commonly referred to as TCP/IP. TCP provides reliability to data transferring in all end-to-end data stream services on the internet. This protocol is utilized by major internet applications such as the e-mail, file transfer, remote administration and world-wide-web. Other applications which do not require reliable data stream service may use the User Datagram Protocol (UDP), which provides a datagram service that emphasizes reduced latency over reliability. The task of determining the available bandwidth of TCP packets flow is in fact, very tedious and complicated. The complexity arises due to the effects of congestion control of both the network dynamics and TCP. Congestion control is an approved mechanism used to detect the optimum bandwidth in which the packets are to be sent by TCP sender. The understanding of TCP behaviour and the approaches used to enhance the performance of TCP in fact, still remain a major challenge. In conjunction to this, a considerable amount of researches has been made, in view of developing a good mechanism to raise the efficiency of TCP performance. The article analyses and investigates the congestion control technique applied by TCP, and indicates the main parameters and requirements required to design and develop a new congestion control mechanism.
International Journal of Communication Networks and Distributed Systems, 2016
In order to curtail the escalating packet loss rates caused by an exponential increase in network traffic, active queue management techniques such as Random Early Detection (RED) have come into picture. Flow Random Early Drop (FRED) keeps state based on instantaneous queue occupancy of a given flow. FRED protects fragile flows by deterministically accepting flows from low bandwidth connections and fixes several shortcomings of RED by computing queue length during both arrival and departure of the packet. Stochastic Fair Queuing (SFQ) ensures fair access to network resources and prevents a busty flow from consuming more than its fair share. In case of (Random Exponential Marking) REM, the key idea is to decouple congestion measure from performance measure (loss, queue length or delay). Stabilized RED (SRED) is another approach of detecting nonresponsive flows. In this paper, we have shown a comparative analysis of throughput, delay and queue length for the various congestion control algorithms RED, SFQ and REM. We also included the comparative analysis of loss rate having different bandwidth for these algorithms.
A reliable end to end communication is a buzzword that is promised by the transport layer protocol TCP. TCP, a Reliable transport protocols are tuned to perform well in different networks but, packet losses occur mostly because of congestion. TCP contains several mechanisms (such as slow start, congestion avoidance, fast retransmit and fast recovery) for ensuring reliability. However, it has reached its limitation in some challenging network environments like-High speed communication, Communication over different media. Thus, it requires further analysis and development of congestion control algorithms. In this paper, we have explored the reliability and robustness of TCP variants (Tahoe, Reno, New-Reno, SACK, FACK and TCP VEGAS, HSTCP, CUBIC TCP) based on different parameters such as throughput, end-to-delay, jitter and packet drop ratio over wired and wireless networks. We have also compared and discussed different congestion control and avoidance mechanisms of TCP variants to show how they affect the throughput and efficiency of different network environments.
Computer Sci. Network Security, 2008
Conventional TCP suffers from poor performance on high bandwidth delay product links meant for supporting transmission rates of multi Gigabits per seconds (Gbps). This is largely due to TCP's congestion control algorithm, which can be slow in taking advantage of large amounts of available bandwidth. A number of high-speed variants have been proposed recently, the major ones being BIC TCP, CUBIC, FAST, High-Speed TCP, Layered TCP, Scalable TCP and XCP. In this paper an effort has been made to comparatively analyze the aforementioned protocols based on various parameters viz., Throughput, Fairness, Stability, Performance, Bandwidth Utilization and Responsiveness and study the limitations of these protocols meant for the High Speed Networks.
Journal of Network and Information Security, 2020
As we know Transmission Control Protocol (TCP) is improving itself with the help of many researchers working in this area all over the World. Many papers and proposals have been submitted by the different researchers to improve the performance of TCP by the congestion control mechanism. In this concern paper, we are able to improve the transmission speed through the window size congestion control technique which is playing an important role in the field of communication. As we already know there are two main important techniques to overcome the congestion and these are the Avoidance algorithm and Slow start mechanism. Now to specify the TCP there are multiple start-ups are existing to specify that start-up speed is selectable from an n-array set of algorithms. If well work and implement these algorithms we can improve our performance and control the congestion. This paper provide the depth analysis of the existing congestion control techniques and provide the model which is helpful to control congestion.
Transmission control protocol (TCP) provides a reliable data transfer in all end-to-end data stream services on the internet. There are some mechanisms that TCP has that make it suitable for this purpose. Over the years, there have been modifications in TCP algorithms starting from the basic TCP that has only slow-start and congestion avoidance algorithm to the modifications and additions of new algorithms. Today, TCP comes in various variants which include TCP Tahoe, Reno, new reno, vegas, sack etc. Each of this TCP variant has its peculiarities, merits and demerits. This paper is a review of four TCP variants, they are: TCP tahoe, Reno, new reno and vegas, their congestion avoidance algorithms, and possible future research areas.
Nowadays, more and more applications require fast transfer of massive data over networks, and the emergences of high-speed networks provide an ideal solution to this challenge. Due to the limitations of the conservative congestion control algorithm, the standard TCP is no longer appropriate for high- speed networks to efficiently utilize the bandwidth resources. A new congestion control algorithms for high-speed networks. It uses packet loss information to determine whether the window size should be increased or decreased, and uses queuing delay information to determine the amount of increment or decrement.
Journal of Engineering and Applied Sciences, 2021
Congestion control in networks is prioritized for maintaining high and error free data rates. The work in this paper directly investigates possible attainment of optimized TCP congestion control over wired networks through a proposed modification done to one of the existing TCP protocols. Firstly, the proposed approach looks into various queue limits e.g. Drop Tail and RED. Evidently, a comparison of these two queue limits vividly demonstrates that RED demonstrates a better performance when it comes to attainment of optimized TCP congestion control. This investigation is naturally followed by simulating different TCP versions such as TCP Tahoe, TCP Sack, TCP NewReno, TCP Reno and TCP Westwood for checking and comparing their effective resource utilization such as network Throughputs, comparative bandwidths, retransmission rates and window sizes. Simulations in this regard were carried through using NS-2 (Network Simulator-2) simulation software. From simulation results, as evident in this paper, TCP Westwood was found to be the best candidate for innovation out of the mentioned flavors based on its output performance. The most active objective of the proposed research presented in this paper was to modify the already chosen TCP Westwood protocol and to come up with a new variant of it proposed here namely as "TCP New-Westwood" for providing a higher degree of TCP congestion control.
Conventional TCP suffers from poor performance on high bandwidth delay product links meant for supporting transmission rates of multi Gigabits per seconds (Gbps). This is largely due to TCP’s congestion control algorithm, which can be slow in taking advantage of large amounts of available bandwidth. A number of high-speed variants have been proposed recently, the major ones being BIC TCP, CUBIC, FAST, High-Speed TCP, Layered TCP, Scalable TCP and XCP. In this paper an effort has been made to comparatively analyze the aforementioned protocols based on various parameters viz., Throughput, Fairness, Stability, Performance, Bandwidth Utilization and Responsiveness and study the limitations of these protocols meant for the High Speed Networks.
International Journal of Information and Electronics Engineering, 2012
Recent years have shown an increased interest towards multimedia rich applications. Multimedia content ranges from text or simple images to audio data or video data. A Next-Generation Network (NGN) is a packet-based network that handles multiple types of traffic (such as voice, data, and multimedia). Multimedia applications include large amount of data, high throughput, and multiple flows which need diverse QoS characteristics. Nowadays, many applications use TCP as their transport protocol. As the network evolves, many improvements and modifications are proposed to make TCP meet various requirements. TCP, although powerful and effective, is not sufficient to satisfy real time applications because TCP emphasizes more on reliability than timeliness. In this paper a new Improvement on TCP (ITCP) protocol is presented. Source rate is regulated based on the feedback which is received from intermediate nodes. Furthermore, in order to satisfy the requirements of different multimedia applications, a weighted random early detection (WRED) mechanism is used. Loss probability is calculated based on the packets priority in a router and the result is sent to source then it regulates its rate based on the packet loss probability values. The proposed protocol was simulated in order to evaluate its performance. Simulation results indicate that the ITCP improves overall system throughput and reduces delay and packet loss. Index Terms-Active queue management (AQM); next generation network (NGN); quality of service (qos);transmission congestion protocol; transport protocol.
2011
Transmission Control Protocol (TCP) is a basic communication language and a connection oriented protocol tied with transport layer consists of collection of rules and procedures to control communication between links. There are many TCP variants that modified and developed with respectively with the communications needs. Most of TCP current versions are include set of algorithms which built to control the congestion in critical links of network with maintaining the network throughput. In present years, TCP has been faced the fast growth in internet in parallel with the demand increasing to transfer the media on high speed links supported TCP. In the last years, computer networks and mobile cellular systems have qualified incredible evolution and a lot of computers and other user equipment's become linked together with most mutual protocol stack used being TCP . Currently, it is hard to recognize the congestion control mechanisms that are applied by different engines in Internet. One more imperative problem is the manner that these mechanisms are employed in diverse operating systems. The greatest universal transport protocol involved is the TCP and in the original accomplishment of TCP, a very small number of variants were done to minimalize the congestion in network path. Employment used accumulative confident acknowledgements and the expiration of a retransmission timer to afford reliability based on a modest go-back-n model. Some successive variants of TCP grounded on the mechanisms of congestion control and avoidance have been proposed and established. This article introducing a study and background to the performance of different congestion control mechanisms with various TCP variants and provide an investigation to the behavior for each mechanism.
Journal of High Speed Networks, 2019
The data networks are basically designed with the aim of maximum throughput and fair resource allocation by managing available resources. A transport layer plays an important role in throughput and fairness with the help of congestion control algorithms (variants). This survey targets mainly congestion issues in high-speed data networks to improve efficiency at connection or flow level. Transmission Control Protocol (TCP) is a dominating transport layer protocol in the existing network because of its reliable service and deployment in most of the routers. A cause of congestion may be different in wired and wireless network and needs to be handled separately. Packet delay, packet loss and time out (RTO) are not caused by congestion in case of wireless network. This has been taken into account in our consideration. To overcome the dominance of TCP, Google proposed UDP based solution to handle congestion control and reliable service with minimum latency and control overhead. In the literature several methods are proposed to classify transport layer Protocols. In this survey congestion control proposals are classified based on situation handled by the algorithm such as pure congestion, link loss, packet reordering, path optimization etc. and at the end congestion control at flow level has been addressed.
2012
The Transmission Control Protocol (TCP) carries most Internet traffic, so performance of the Internet depends to a great extent on how well TCP works. Performance characteristics of a particular version of TCP are defined by the congestion control algorithm it employs. This paper presents a survey of various congestion control proposals that preserve the original host-to-host idea of TCP—namely, that neither sender nor receiver relies on any explicit notification from the network. The proposed solutions focus on a variety of problems, starting with the basic problem of eliminating the phenomenon of congestion collapse, and also include the problems of effectively using the available network resources in different types of environments(wired, wireless, high-speed, long-delay, etc.). In a shared, highly distributed, and heterogeneous environment such as the Internet, effective network use depends not only on how well a single TCP based application can utilize the network capacity, but...
This paper is aimed at describing a delay-based endto-end (e2e) congestion control algorithm, called Very FAST TCP (VFAST), which is an enhanced version of FAST TCP. The main idea behind this enhancement is to smoothly estimate the Round-Trip Time (RTT) based on a nonlinear filter, which eliminates throughput and queue oscillation when RTT fluctuates. In this context, an evaluation of the suggested scheme through simulation is introduced, by comparing our VFAST prototype with FAST in terms of throughput, queue behavior, fairness, stability, RTT and adaptivity to changes in network. The achieved simulation results indicate that the suggested protocol offer better performance than FAST TCP in terms of RTT estimation and throughput.
University of Helsinki, 2010
This paper is an exploratory survey of TCP congestion control principles and techniques.In addition to the standard algorithms used in common software implementations of TCP,this paper also describes some of the more common proposals developed by researchersover the years. By studying congestion control techniques used in TCP implementationsoftware and network hardware we can better comprehend the performance issues of packet switched networks and in particular, the public Internet.
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