TCP Variants Research Articles

Evaluation of TCP Congestion Control Algorithms with traffic control policies in a PEP-based geosynchronous satellite scenario

Much work has been done in recent years comparing TCP variants in many scenarios, including the satellite one. Some of these studies were carried out with the ns-2 and ns-3 simulators, which may give a good idea of the behavior of these TCP variants, although the results cannot be considered completely realistic. Some of the latest studies use virtualization to derive a variety of measures to test the suitability of Congestion Control Algorithms in a more realistic way. Such studies also take into account new variants of TCP, such as Google’s BBR. However, few of these works have evaluated the behavior of these variants in a scenario based on Performance Enhancing Proxies. Furthermore, no emphasis has been placed on those variants of TCP that try to maximize throughput and minimize delay, which is crucial in many services with low latency requirements. Our paper aims to fill this gap, offering a comparative assessment of the performance of these three TCP flavors: BBR, YeAH and CUBIC. We have created four different approaches to mix these TCP flavors with two traffic control techniques, including Active Queue Management (AQM) policies. To perform the testings, we have developed a TCP-Splitting satellite Emulation Framework (TSEF), a platform that allows us to evaluate the performance of TCP flavors on the forward channel of a geosynchronous satellite scenario based on Performance Enhancing Proxies (PEPs). According to our results, we can conclude that the application of AQM policies and ECN marks on aggressive TCP flavors like CUBIC is mandatory to maximize throughput and minimize delay.

Comparative Performance Testing of the Impact of ACK Loss in TCP Tahoe, TCP Reno, and TCP New Reno on the ns-2 Simulator

In TCP/IP networks, TCP provides reliable delivery service with the guarantee that packets sent reach their destination. This is achieved through the use of acknowledgments (ACK) as a mechanism. In TCP/IP networks, TCP provides reliable delivery service with the guarantee that packets sent reach their destination. This is achieved through the use of acknowledgments (ACK) as a mechanism. In all three variants of TCP, they rely on the presence of ACK packets. Therefore, testing will be conducted to observe the effect of ACK loss on TCP performance. The testing involves introducing disruptive traffic on the ACK path with varying magnitudes. This disruptive traffic results in the loss of some ACK packets, depending on the magnitude of the disruptive traffic. The testing was conducted using the ns-2 simulator software. The research findings indicate that the loss of ACK packets leads to a decrease in TCP performance. TCP Reno successfully improves the performance of TCP Tahoe, but the algorithm improvement in TCP New Reno does not have an effect on TCP Reno..

Impact of Jellyfish attack on routing protocols in TCP-based MANETs

Mobile ad-hoc networks (MANETs) are self-organized infrastructure-less network of mobile wireless devices that could be deployed for communication. Due to the insecure wireless communication medium, multi-hop routing communication process, and dynamic behavior of the nodes in MANETs, routing protocols are vulnerable to various security attacks, such as Jellyfish attacks. A Jellyfish node targets TCP-based MANET and exploits its working mechanism to degrade the communication performance. This attack is hard to detect since it is a TCP protocol compliant methodology.In this paper, we evaluate the performance of the Ad hoc on-demand vector (AODV), Dynamic source routing (DSR), Temporally ordered routing algorithm (TORA), Geographic routing protocol (GRP), and optimized link state routing (OLSR) routing protocols under the Jellyfish delay variance attacks for TCP-based MANETs. Further, the TAHOE, RENO, and SACK variants of TCP protocol are considered for comparison. These routing protocols are simulated using the OPNET simulator to compare their performance, using specific performance metrics on the network. The experimental results show that the AODV protocol performs better than the DSR, TORA, OLSR, and GRP protocols under the jellyfish delay variance attack. Further, the SACK TCP variant performs better than the other TCP variants under the Jellyfish delay variance attack.

Aggregating Without Bloating: Hard Times for TCP on Wi-Fi

Since the definition of the bufferbloat phenomenon, several Linux kernel modules have been introduced in its TCP/IP stack, and there is a lack of experimental studies on their effects when coupled with WLAN technologies, in particular, IEEE 802.11n and IEEE 802.11ac. One essential algorithm introduced is named TCP Small Queues (TSQ) and has the role of limiting the number of packets that a TCP socket can enqueue in the stack, waiting for the physical layer to send the packets before enqueueing extra data. A second significant TCP algorithm is named TCP Pacing (TP) and regulates the pace used by the socket to enqueue packets in the stack, regulating the formation of bursts of data. These mechanisms affect the frame aggregation logic on WLAN networks and compromise the throughput-latency tradeoff of all the TCP variants. This paper presents an experimental evaluation of these techniques investigating the wireless network performance of several TCP congestion control variants under the presence of different TSQ and TP policies, modeling also their interaction.

Revisiting legacy high-speed TCP congestion control variants: An optimisation-theoretic analysis of multi-mode TCP

We revisit the problem of link capacity under-utilisation in TCP Congestion Control (TCP-CC) when working in High-Bandwidth-Delay-Product (High-BDP) networks. We approach this problem using a multi-mode approach and propose TCP-Gentle as an example of TCP-CC that uses this approach. While General Additive Increase Multiplicative Increase (GAIMD) congestion control algorithms received a lot of attention in the literature, little was mentioned about modelling multi-mode GAIMD. To this aim, we provide a tractable optimisation-theoretic model for TCP-Gentle which can be generalised to any multi-mode GAIMD. We show through analysis, simulation, and real-test-bed experiments of single flow, double flow, and single flow with background web traffic, that the proposed TCP-Gentle is competitive with existing TCP variants. Particularly, under certain assumption, TCP-Gentle can outperform TCP-YeAH in terms of fairness to TCP-NewReno. Besides, the proposed TCP-Gentle is more gentle to network; it maintains minimal average queues of less than 1.5% of pipe’s BDP, and reassembles to a great extent a highly-concave congestion window.

TCP-WBQ: a backlog-queue-based congestion control mechanism for heterogeneous wireless networks

In heterogeneous wireless networks, random packet loss and high latency lead to conventional TCP variants performing unsatisfactorily in the case of competing communications. Especially on high-latency wireless links, conventional TCP variants are unable to estimate congestion degrees accurately for fine-grained congestion control because of the effects of random packet loss and delay oscillations. This paper proposes a TCP variant at the sender side to identify congestion degrees, namely TCP-WBQ, which quickly responses to the real congestion and effectively shields against random packet loss and oscillations of latency time. The proposed algorithm of congestion control firstly constructs a backlog-queue model based on the dynamics of the congestion window, and deduces the two bounds of the model which delimit oscillations of the backlog queue for non-congestion and random packet loss respectively. TCP-WBQ detects congestion degrees more accurately and thus implements the corresponding schemes of adjusting the congestion window, maintaining a tradeoff between high throughputs and congestion avoidance. The comprehensive simulations show that TCP-WBQ works efficiently in bandwidth utilization with single and multiple bottleneck scenarios, and achieves high performance and competitive fairness in heterogeneous wireless networks.

Extended Evaluation of Loss-Based TCP Variants Performance Over Optical Burst Switching (OBS) Networks for Case W x =W max

Extended Evaluation of Loss-Based TCP Variants Performance Over Optical Burst Switching (OBS) Networks for Case W x =W max

TCPW-F: A Congestion Control Algorithm Based on Noise-aware in Wireless Networks

Due to the wireless link with more noise packet loss and higher latency as compared with the wired link, conventional TCP Westwood (TCPW) variants over wireless channels perform unsatisfactorily when competing for the shared capacity of the bottleneck link with other variants. The shortcoming is these variants mistakenly interpret noise packet loss as a congestion signal. This leads to frequent delay jitter and long latency due to the inability to distinguish the type of packet loss, which reduces the transmission efficiency of the network. Therefore, we propose a novel TCP variant (TCPW-F) that distinguishes noise loss and congestion loss. By constructing the congestion factor F, the real-time available bandwidth can be calculated. When receiving congestion signals, it ignores the false of them induced by noise packet loss upon the wireless link but responds to true congestion according to backlog-constrained-based judgment. Therefore, TCPW-F is widely used in wireless networks with large noise interference. Numerical analysis and simulation results show that TCPW-F resists noise interference, and smooths the delay jitter per unit time. And the throughput of TCPW-F is significantly higher than other TCPW variants. TCPW-F improves the transmission performance in wireless networks.

Performance Analysis of TCP Variants Using AODV and DSDV Routing Protocols in MANETs

Background: TCP is the most reliable transport layer protocol that provides reliable data delivery from source to destination node. The background of TCP suggests that it works well in wired networks but it is assumed that TCP is less preferred for ad-hoc networks. However, for application in ad-hoc networks, TCP can be modified to improve its performance. Various researchers have proposed improvised variants of TCP by only one or two measures. Objective: These one or two measures do not seem to be sufficient for proper analysis of improvised version of TCP. Therefore, in this paper, our objective is to evaluate the performance of different TCP variants and their results are investigated with DSDV and AODV routing protocols. Methods: Our methodology includes the analysis of various performance measures such as throughput, delay, packet drop, packet delivery ratio and number of acknowledgements. The simulation results are carried out by varying number of nodes in network simulator tool NS2. Results: It is observed in results that TCP Newreno achieved higher throughput and packet delivery ratio with both AODV and DSDV routing protocols. Whereas TCP Vegas achieved minimum delay and packet loss with both DSDV and AODV protocol. However TCP sack achieved minimum acknowledgment with both AODV and DSDV routing protocols. Conclusion: The comparison of all these TCP variants helps in drawing conclusion that, TCP Newreno provides better performance with both AODV and DSDV protocols.

A Machine-Learning-Based Tool for Passive OS Fingerprinting With TCP Variant as a Novel Feature

With the emergence of Internet of Things (IoT), securing and managing large, complex enterprise network infrastructure requires capturing and analyzing network traffic traces in real time. An accurate passive operating system (OS) fingerprinting plays a critical role in effective network management and cybersecurity protection. Passive fingerprinting does not send probes that introduce extra load to the network and hence it has a clear advantage over active fingerprinting since it also reduces the risk of triggering false alarms. This article proposes and evaluates an advanced classification approach to passive OS fingerprinting by leveraging state-of-the-art classical machine learning and deep learning techniques. Our controlled experiments on benchmark data, emulated, and realistic traffic is performed using two approaches. Through an Oracle-based machine learning approach, we found that the underlying TCP variant is an important feature for predicting the remote OS. Based on this observation, we develop a sophisticated tool for OS fingerprinting that first predicts the TCP flavor using passive traffic traces and then uses this prediction as an input feature for another machine learning algorithm for predicting the remote OS from passive measurements. This article takes the passive fingerprinting problem one step further by introducing the underlying predicted TCP variant as a distinguishing feature. In terms of accuracy, we empirically demonstrate that accurately predicting the TCP variant has the potential to boost the evaluation performance from 84% to 94% on average across all our validation scenarios and across different types of traffic sources. We also demonstrate a practical example of this potential, by increasing the performance to 91.2% and 95.3% on average using a tool for loss-based and delay-based TCP variants prediction in an emulated setting. To the best of our knowledge, this is the first study that explores the potential for using the knowledge of the TCP variant to significantly boost the accuracy of passive OS fingerprinting.

A green multipath TCP framework for industrial internet of things applications

The concurrent use of a few transmission channels offered by the multipath version of the TCP protocol (MPTCP) becomes a widely accepted remedy for the quality of service and reliability issues. However, the common approaches to the multipath transfer organization do not give sufficient attention to the energy aspects, which are crucial for the resource-constrained devices in the Internet of Things domain. In this paper, a systematic tuning methodology of the MPTCP architectural modules – targeting the energy expenditure – is developed. By adopting a formal optimization approach, a new Scheduler, and a new Path Manager that promote conservative energy usage are designed. The proposed ‘green’ modules versions do not augment the protocol complexity. Next, explicit guidelines for the selection of the TCP variant to be used at the individual paths are provided. As confirmed by experiments involving physical devices and real networks, the established framework reduces the amount of dissipated energy by several percent (up to 50%) with respect to the default one. As a beneficial side-effect, the transmission throughput is increased and the protocol delay shortened in the uncertain networking conditions typical of industrial settings.

How Sufficient is TCP When Deployed in 5G mmWave Networks Over the Urban Deployment?

By deploying the millimeter-wave wide spectrum in 5G networks, the new generation is capable of providing high data rates with low latencies. However, these frequencies have intermittent characteristics as their downside, which acts as a hurdle on the way of attaining high performances. This disadvantage can lower signals' penetration power in reaching far distances or passing materials such as vehicles, walls, and even human bodies. As a result, having a reliable end-to-end connection throughout 5G millimeter-wave networks can be challenging because this burden is on the transport layer mostly exploited protocol, TCP, which is unable to perform sufficiently due to the fluctuation of the high-frequency channels. This paper aims to analyze TCP's behavior in one of the 3GPP's well-known scenarios called urban deployment. The detailed investigation of TCP over 5G millimeter-wave when used in a city and the impact of different parameters such as remote servers, RLC buffer size, different congestion control algorithms, and maximum segment size are discussed thoroughly throughout the paper. The results revealed that TCP could benefit from the edge server deployment due to the shorter control loop, and increasing maximum segment size can also enhance this superiority. Moreover, individual TCP variants react to various RLC buffer sizes differently. However, in general, increased throughput can be attained by deploying larger buffers at the cost of latency.

Study on performance of AQM schemes over TCP variants in different network environments

Study on performance of AQM schemes over TCP variants in different network environments

Rethinking Fast and Friendly Transport in Data Center Networks

The sustainable growth of bandwidth has been an inevitable tendency in current Data Center Networks (DCN). However, the dramatic expansion of link capacity offers a remarkable challenge to the transport layer protocols of DCN, i.e., how to converge fast and enable data flow to utilize the high bandwidth effectively. Meanwhile, the new protocol should be compatible to the traditional TCP because the applications with old TCP versions are still widely deployed. Therefore, it is important to achieve a trade-off between the aggressiveness and TCP-friendliness in protocol design. In this article, we first empirically investigate why the existing typical data center TCP variants naturally fail to guarantee both fast convergence and TCP friendliness. Then, we design a new transport protocol for DCN, namely Fast and Friendly Converging (FFC), which makes independent decisions and self-adjustment through retrieving the two-dimensional congestion notification from both RTT and ECN. We further present a mathematic model to analyze its competing behavior and converging process. The results from simulation experiments and real implementation show that FFC can achieve fast convergence, thus benefiting the flow completion time. Moreover, when coexisting with the traditional TCP, FFC also presents a moderate behavior, while introducing trivial deployment overhead only at the end-hosts.

TCP CERL+: revisiting TCP congestion control in wireless networks with random loss

In this paper, we analyze the performance of wireless networks subject to random loss. In this regard, we revisit our TCP Congestion Control Enhancement for Random Loss (CERL) mechanism that has been introduced earlier in a previous study. We call our new developed TCP variant as CERL Plus (CERL+). TCP CERL+ is a modification of TCP Reno at sender-side. TCP CERL+ is a new generation that works similarly as TCP CERL but its main idea is to use a dynamic threshold in terms of RTT. In doing this, we employ the average RTT and its minimum measurements made over the connection to estimate the queue length of the bottleneck link. As a result, we can use this queue length to evaluate the congestion status and distinguish it from the random loss status. This in turn would not reduce the window size leading to enhance the performance of the proposed algorithm in the sense of increasing the amount of data transmission. Additionally, CERL+ alleviates the congestion in the bottleneck obviously. In this paper, we present simulation experiment for TCP CERL+ considering a two-way transmission assuming a heavy load and wide range of random loss rates compared to TCP NewReno, TCP New Jersey + , TCP mVeno, TCP Westwood + , TCP Cubic and TCP YeAh using the network simulation ns-2. Simulation results prove that CERL+ outperforms other TCP variants and achieves excellent throughput gain.

Performance Analysis of TCP Variants in Named Data Networking

Performance Analysis of TCP Variants in Named Data Networking

The Great Internet TCP Congestion Control Census

In 2016, Google proposed and deployed a new TCP variant called BBR. BBR represents a major departure from traditional congestion control as it uses estimates of bandwidth and round-trip delays to regulate its sending rate. BBR has since been introduced in the upstream Linux kernel and deployed by Google across its data centers. Since the last major study to identify TCP congestion control variants on the Internet was done before BBR, it is timely to conduct a new census to give us a sense of the current distribution of congestion control variants on the Internet. To this end, we designed and implemented Gordon, a tool that allows us to measure the congestion window (cwnd) corresponding to each successive RTT in the TCP connection response of a congestion control algorithm. To compare a measured flow to the known variants, we created a localized bottleneck and introduced a variety of network changes like loss events, changes in bandwidth and delay, while normalizing all measurements by RTT. We built an offline classifier to identify the TCP variant based on the cwnd trace over time.

Improving Throughput in Lossy Wired/Wireless Networks

Wireless communication is more prone to random loss than wired communication because of noise and mobility. Over years researchers have developed TCP variants that do not decrease the send window when random loss arises. Years ago it was introduced TCP CERL algorithm that proved to present a high performance compared to other protocols. Here, we test CERL assuming two-way transmission of relatively heavy load and compare with TCP BIC, TCP NewReno, TCP Westwood+, TCP NewJersey and TCP Illinois. Simulation Results show that TCP CERL gains a 145%, 137%, 120%, 97% and 125% throughput improvement over New Reno, Bic, Westwood+, New Jersey and Illinois, respectively.

Dynamic Congestion Control Mechanism in Mobile Adhoc Network: TCP Westwood-DCC

Transmission control protocol faces a problem of packet loss differentiation in the wireless and mobile adhoc network. Congestion control is not properly done here. It cannot manage the congestion window as per type of loss and it reduces Congestion window unnecessarily and that degrades the performance. TCP Westwood cannot identify congestion or link failure loss, and it cannot manage the congestion window as per available bandwidth. This paper discusses that TCP Westwood performs bandwidth estimation, setting up a congestion window and a slow start threshold. In mobile adhoc network, link failure may happen frequently, and it should be handled properly. Link failure can be detected with the help of retransmission timeout. Once timeout occurs Westwood performs congestion avoidance. Proposed Westwood manages three states of congestion 1) Avoidance 2) congestion and 3) No congestion, it updates congestion window and slow start threshold as per the status of network. It maintains congestion window dynamically. Network status is identified by estimated bandwidth and proportionality ratio. Proposed method is tested on NS2.35 and compared with the existing TCP variants. The proposed Westwood performs optimized link utilization and congestion control mechanism. Hence it gives significant performance for loss recovery.

BBRp: Improving TCP BBR Performance Over WLAN

This paper shows the inefficiency of TCP BBR in exploiting the Wi-Fi bandwidth. This limitation of BBR has been observed with both IEEE 802.11n and IEEE 802.11ac, where the mechanism of frame aggregation is used to boost the throughput of data transmission. In the last years, many TCP variants have been introduced to limit the bufferbloat phenomena and bound the latency through a reduction of the queue backlog injection rate. However, this mechanism impacts on the Wi-Fi frame aggregation logic, impeding TCP congestion controls to reach the full throughput potential of a Wi-Fi interface. While this problem can be solved with TCP Cubic by allowing the sender node to enqueue more packets, for TCP BBR the fix is not the same, as it has a customized pacing algorithm. With this contribution we propose BBRp, a new BBR version that allows for fine-tuning the congestion control pace, achieving between four and six times more throughput over IEEE 802.11n and IEEE 802.11ac channels, at the cost of an increased latency that is however always less than the latency obtainable with loss-based TCP congestion controls.