scholarly journals Performance Evaluation of TCP Vegas over TCP Reno and TCP NewReno over TCP Reno

2019 ◽  
Vol 3 (3) ◽  
Author(s):  
Tanjia Chowdhury ◽  
Mohammad Jahangir Alam
Keyword(s):  
Congestion Control ◽  
Error Detection ◽  
Transmission Control Protocol ◽  
Control Flow ◽  
Transport Layer ◽  
Control Mechanisms ◽  
Bottleneck Link ◽  
Tcp Vegas ◽  
Congestion Control Mechanism ◽  
Tcp Reno

In the Transport layer, there are two types of Internet Protocol are worked, namely- Transmission Control Protocol (TCP) and User datagram protocol (UDP). TCP provides connection oriented service and it can handle congestion control, flow control, and error detection whereas UDP does not provide any of service. TCP has several congestion control mechanisms such as TCP Reno, TCP Vegas, TCP New Reno, TCP Tahoe, etc. In this paper, we have focused on the behavior performance between TCP Reno and TCP Vegas, TCP New Reno over TCP Reno, when they share the same bottleneck link at the router. For instigating this situation, we used drop-tail and RED algorithm at the router and used NS-2 simulator for simulation. From the simulation results, we have observed that the performance of TCP Reno and TCP Vegas is different in two cases. In drop tail algorithm, TCP Reno achieves better Performance and throughput and act more an aggressive than Vegas. In Random Early Detection (RED) algorithm, both of congestion control mechanism provides better fair service when they coexist at the same link. TCP NewReno provides better performance than TCP Reno.

TCP for High-Speed Networks

2008 ◽  
pp. 626-632
Author(s):  
Nelson Luís Saldanha da Fonseca ◽  
Neila Fernanda Michel
Keyword(s):  
Congestion Control ◽  
High Speed ◽  
Transmission Control Protocol ◽  
Window Size ◽  
Transport Layer ◽  
The Internet ◽  
Congestion Window ◽  
High Speed Networks ◽  
Congestion Control Mechanism ◽  
Tcp Reno

In response to a series of collapses due to congestion on the Internet in the mid-’80s, congestion control was added to the transmission control protocol (TCP) (Jacobson, 1988), thus allowing individual connections to control the amount of traffic they inject into the network. This control involves regulating the size of the congestion window (cwnd) to impose a limit on the size of the transmission window. In the most deployed TCP variant on the Internet, TCP Reno (Allman, Floyd, & Partridge, 2002), changes in congestion window size are driven by the loss of segments. Congestion window size is increased by 1/cwnd for each acknowledgement (ack) received, and reduced to half for the loss of a segment in a pattern known as additive increase multiplicative decrease (AIMD). Although this congestion control mechanism was derived at a time when the line speed was of the order of 56 kbs, it has performed remarkably well given that the speed, size, load, and connectivity of the Internet have increased by approximately six orders of magnitude in the past 15 years. However, the AIMD pattern of window growth seriously limits efficienct operation of TCP-Reno over high-capacity links, so that the transport layer is the network bottleneck. This text explains the major challenges involved in using TCP for high-speed networks and briefly describes some of the variations of TCP designed to overcome these challenges.

Comparative Performance Evaluation of TCP with Identical and Cross-Variant Congestion Control

2018 ◽  
Vol 8 (1) ◽  
pp. 163
Author(s):  
Nahida Nigar
Keyword(s):  
Performance Evaluation ◽  
Congestion Control ◽  
Transmission Control Protocol ◽  
Injection Rate ◽  
Transport Layer ◽  
Performance Criteria ◽  
Control Mechanisms ◽  
Comparative Performance ◽  
Rate Adaptive ◽  
Tcp Vegas

The Transmission Control Protocol (TCP), a key functional building block of the Internet, operates as a rate-adaptive end-to-end protocol at the Transport Layer of the network protocol stack. It regulates the prevailing load conditions within the network by getting the source node to adapt the packet transfer rate in accord with the processing capacity of the receiver. The regulation is enforced by means of dropping of packets on the part of the receiver. The TCP sender then reduces the packet injection rate so as to allow the network to recover from congestion. The focus of this paper is performance evaluation of certain notable TCP congestion avoidance algorithms, namely, Vegas, Reno and New Reno. Specifically, a number of performance measures have been analysed based on ns-2 simulation data where the scenarios involved TCP flows operating with identical and cross-variant congestion control mechanisms. Congestion window behaviour, packet loss, throughput, transmission delay and jitter are the performance criteria studied with the setup mentioned. In the flows with identical variants, Vegas outperforms other TCP variants. However, TCP Vegas has been observed to contribute to unfair appropriation of the resources in the cross-variant setting.

TCP-AP Enhanced Behaviour With rt-Winf And Node Count: boosted-TCP-AP

2015 ◽  
Vol 7 (2) ◽  
pp. 1
Author(s):  
Luis Barreto
Keyword(s):  
Wireless Networks ◽  
Congestion Control ◽  
Ad Hoc ◽  
Control Mechanisms ◽  
Mac Layer ◽  
Available Bandwidth ◽  
Wireless Links ◽  
Wireless Mesh ◽  
Congestion Control Mechanism ◽  
Hoc Networks

<p>Congestion control in wireless networks is strongly dependent on the dynamics and instability of wireless links. Therefore, it is very difficult to accurately evaluate the characteristics of the wireless links. It is known that TCP experiences serious performance degradation problems in wireless networks. New congestion control mechanisms, such as TCP-AP, do not evaluate accurately the capacity and available link bandwidth in wireless networks. In this paper we propose new congestion control protocol for wireless networks, based in TCP-AP. We name the protocol boosted-TCP-AP. It relies on the MAC layer information gathered by a new method to accurately estimate the available bandwidth and the path capacity over a wireless network path (rt-Winf), and also takes into consideration the node path count. The new congestion control mechanism is evaluated in different scenarios in wireless mesh and ad-hoc networks, and compared against several new approaches for wireless congestion control. It is shown that boosted-TCP-AP outperforms the base TCP-AP, showing its stable behavior and better channel utilization.</p>

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

2020 ◽  
Vol 8 (5) ◽  
pp. 4784-4789
Keyword(s):  
Congestion Control ◽  
Control Mechanism ◽  
Transmission Control Protocol ◽  
Link Failure ◽  
Congestion Window ◽  
Slow Start ◽  
Mobile Adhoc Network ◽  
Adhoc Network ◽  
Tcp Westwood ◽  
Congestion Control Mechanism

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.

TCP Enhancements for Mobile Internet

2008 ◽  
pp. 619-625
Author(s):  
Bhaskar Sardar ◽  
Debashis Saha
Keyword(s):  
Traffic Control ◽  
Transmission Control Protocol ◽  
Research Literature ◽  
Mobile Internet ◽  
Transport Layer ◽  
Control Mechanisms ◽  
Packet Losses ◽  
Internet Applications ◽  
Wired Networks ◽  
Mobile Access

Transmission Control Protocol (TCP), the most popular transport layer communication protocol for the Internet, was originally designed for wired networks, where bit error rate (BER) is low and congestion is the primary cause of packet loss. Since mobile access networks are prone to substantial noncongestive losses due to high BER, host motion and handoff mechanisms, they often disturb the traffic control mechanisms in TCP. So the research literature abounds in various TCP enhancements to make it survive in the mobile Internet environment, where mobile devices face temporary and unannounced loss of network connectivity when they move. Mobility of devices causes varying, increased delays and packet losses. TCP incorrectly interprets these delays and losses as sign of network congestion and invokes unnecessary control mechanisms, causing degradation in the end-to-end good put rate. This chapter provides an in-depth survey of various TCP enhancements which aim to redress the above issues and hence are specifically targeted for the mobile Internet applications.

scholarly journals Adaptive Decrease Window for BALIA (ADW-BALIA): Congestion Control Algorithm for Throughput Improvement in Nonshared Bottlenecks

Electronics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 294
Author(s):  
Geon-Hwan Kim ◽  
Yeong-Jun Song ◽  
Imtiaz Mahmud ◽  
You-Ze Cho
Keyword(s):  
Congestion Control ◽  
Control Algorithm ◽  
Transmission Control Protocol ◽  
Control Mechanisms ◽  
Congestion Window ◽  
Transmission Control ◽  
Control Protocol ◽  
Congestion Control Algorithm ◽  
Lossy Links ◽  
Single Path

The main design goals of the multipath transmission control protocol (MPTCP) are to improve the throughput and share a common bottleneck link fairly with a single-path transmission control protocol (TCP). The existing MPTCP congestion control algorithms achieve the goal of fairness with single-path TCP flows in a shared bottleneck, but they cannot maximize the throughput in nonshared bottlenecks, where multiple subflows traverse different bottleneck links. This is because the MPTCP is designed not to exceed the throughput of a single-path TCP competing in the bottleneck. Therefore, we believe that MPTCP congestion control should have different congestion window control mechanisms, depending on the bottleneck type. In this paper, we propose an adaptive decrease window (ADW) balanced linked adaptation (BALIA) congestion control algorithm that adaptively adjusts the congestion window decrease in order to achieve better throughput in nonshared bottlenecks while maintaining fairness with the single-path TCP flows in shared bottlenecks. The ADW-BALIA algorithm detects shared and nonshared bottlenecks based on delay fluctuations and it uses different congestion window decrease methods for the two types of bottleneck. When the delay fluctuations of the MPTCP subflows are similar, the ADW-BALIA algorithm behaves the same as the existing BALIA congestion control algorithm. If the delay fluctuations are dissimilar, then the ADW-BALIA algorithm adaptively modulates the congestion window reduction. We implement the ADW-BALIA algorithm in the Linux kernel and perform an emulation experiment that is based on various topologies. ADW-BALIA improves the aggregate MPTCP throughput by 20% in the nonshared bottleneck scenario, while maintaining fairness with the single-path TCP in the shared bottleneck scenario. Even in a triple bottleneck topology, where both types of bottlenecks exist together, the throughput increases significantly. We confirmed that the ADW-BALIA algorithm works stably for different delay paths, in competition with CUBIC flows, and with lossy links.

Research of Hybrid Congestion Control Mechanism

2012 ◽  
Vol 426 ◽  
pp. 275-278
Author(s):  
Cheng Yu Lai ◽  
Xiao Guang Fu
Keyword(s):  
Wireless Sensor Networks ◽  
Sensor Networks ◽  
Congestion Control ◽  
Energy Saving ◽  
Control Mechanism ◽  
Wireless Sensor ◽  
Forward Rate ◽  
Control Mechanisms ◽  
Channel Quality ◽  
Congestion Control Mechanism

In wireless sensor networks, congestion causes overall channel quality to degrade and loss rates to raise, leads to buffer drops and increased delays, and tends to be grossly unfair toward nodes whose data has to traverse a larger number of radio hops. Hybrid congestion control mechanisms relieve the congestion by creating the new path; when establishment of a new path is failed, fairness aggregate mechanisms limits forward rate, ensures that each source node sends data fairly. Based on energy-saving, algorithms for mild congestion have been improved.

Congestion Control in Data Center Networks: A Survey and New Perspectives

2013 ◽  
Vol 462-463 ◽  
pp. 1028-1035
Author(s):  
Hang Xing Wu ◽  
Xiao Long Yang ◽  
Min Zhang
Keyword(s):  
Congestion Control ◽  
Data Center ◽  
Data Centers ◽  
Web Applications ◽  
Control Mechanism ◽  
Control Mechanisms ◽  
Data Center Networks ◽  
Huge Amount ◽  
Advantages And Disadvantages ◽  
Congestion Control Mechanism

Nowadays data centers have been becoming increasingly important for various web applications, huge amount of cost is invested to maintain good performance of data center. Whereas some studies indicated that TCP Incast phenomenon was widely observed in most of data centers, which results in congestion in data centers and damages the performance of data center greatly. Thus some congestion control mechanisms for data center have been proposed to solve the problems. These mechanisms are categorized and described in this paper, and the advantages and disadvantages of these mechanisms are analyzed. Subsequently, some new interesting topics which may be worthy of further study in congestion control mechanism on data center are presented.

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