scholarly journals Improvement of RTT Fairness Problem in BBR Congestion Control Algorithm by Gamma Correction

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4128
Author(s):  
Wansu Pan ◽  
Xiaofeng Li ◽  
Haibo Tan ◽  
Jinlin Xu ◽  
Xiru Li
Keyword(s):  
Congestion Control ◽  
Control Algorithm ◽  
Path Model ◽  
Correction Function ◽  
Propagation Time ◽  
Network Simulator ◽  
Gamma Correction ◽  
Round Trip ◽  
Feedback Information ◽  
Congestion Control Algorithm

Google proposed the bottleneck bandwidth and round-trip propagation time (BBR), which is a new congestion control algorithm. BBR creates a network path model by measuring the available bottleneck bandwidth and the minimum round-trip time (RTT) to maximize delivery rate and minimize latency. However, some studies have shown that there are serious RTT fairness problems in the BBR algorithm. The flow with longer RTT will consume more bandwidth and the flows with shorter RTT will be severely squeezed or even starved to death. Moreover, these studies pointed out that even small RTT differences will lead to the throughput of BBR flows being unfair. In order to solve the problem of RTT fairness, an improved algorithm BBR-gamma correction (BBR-GC) is proposed. BBR-GC algorithm takes RTT as feedback information, and then uses the gamma correction function to fit the adaptive pacing gain. This approach can make different RTT flows compete for bandwidth more fairly, thus alleviating the RTT fairness issue. The simulation results of Network Simulator 3 (NS3) show that that BBR-GC algorithm cannot only ensure the channel utilization, but also alleviate the RTT fairness problem of BBR flow in different periods. Through the BBR-GC algorithm, RTT fairness is improved by 50% and the retransmission rate is reduced by more than 26%, compared with that of the original BBR in different buffer sizes.

scholarly journals Improved RTT Fairness of BBR Congestion Control Algorithm Based on Adaptive Congestion Window

Electronics ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 615
Author(s):  
Wansu Pan ◽  
Haibo Tan ◽  
Xiru Li ◽  
Xiaofeng Li
Keyword(s):  
Congestion Control ◽  
Control Algorithm ◽  
Delivery Rate ◽  
Propagation Time ◽  
Network Simulator ◽  
Round Trip ◽  
Congestion Window ◽  
Queuing Delay ◽  
Congestion Control Algorithm ◽  
Tcp Congestion Control

To alleviate the lower performance of Transmission Control Protocol (TCP) congestion control over complex network, especially the high latency and packet loss scenario, Google proposed the Bottleneck Bandwidth and Round-trip propagation time (BBR) congestion control algorithm. In contrast with other TCP congestion control algorithms, BBR adjusted transfer data by maximizing delivery rate and minimizing delay. However, some evaluation experiments have shown that the persistent queues formation and retransmissions in the bottleneck can lead to serious fairness issues between BBR flows with different round-trip times (RTTs). They pointed out that small RTT differences cause unfairness in the throughput of BBR flows and flows with longer RTT can obtain higher bandwidth when competing with the shorter RTT flows. In order to solve this fairness problem, an adaptive congestion window of BBR is proposed, which adjusts the congestion window gain of each BBR flow in network load. The proposed algorithms alleviate the RTT fairness issue by controlling the upper limit of congestion window according to the delivery rate and queue status. In the Network Simulator 3 (NS3) simulation experiment, it shows that the adaptive congestion window of BBR (BBR-ACW) congestion control algorithm improves the fairness by more than 50% and reduces the queuing delay by 54%, compared with that of the original BBR in different buffer sizes.

scholarly journals Performance of TCP CUBIC and TCP BBR on IEEE802.11s Mesh Network

2020 ◽  
pp. 639-645
Author(s):  
Katsuya Atsuta ◽  
◽  
Satoshi Kouya ◽  
Naoshi Sakamoto
Keyword(s):  
Congestion Control ◽  
Bit Error Rate ◽  
Error Rate ◽  
Control Algorithm ◽  
Loss Probability ◽  
Mesh Network ◽  
Propagation Time ◽  
Round Trip ◽  
Communication Performance ◽  
Congestion Control Algorithm

In this study, IEEE802.11s mesh networking was formulated as it expected to be widely used because of its convenience. The properties of IEEE802.11s mesh networking were investigated and the results revealed its faulty communication performance in a multi-hop network. This could be explained based on Mathis’s theory for loss-based TCP congestion control algorithm that suggests that with an increase in delay, the loss probability decreases the communication performance. Recently, Google proposed TCP Bottleneck Bandwidth and Round-trip propagation time (BBR), both of which may tolerate a high bit error rate. This algorithm does not follow Mathis’s model. In this study, we measure the performance of TCP CUBIC and TCP BBR on a mesh network, followed by an evaluation of the properties of this mesh network.

An Analysis to Improve Congestion Algorithm of TCP

2010 ◽  
Vol 171-172 ◽  
pp. 756-759
Author(s):  
Kun Shang ◽  
Zhi Hua Zhai
Keyword(s):  
Congestion Control ◽  
Data Transmission ◽  
Control Algorithm ◽  
Round Trip Time ◽  
Round Trip ◽  
Trip Time ◽  
Congestion Control Algorithm ◽  
End To End

Congestion is an important issue in the research of end-to-end congestion control. The congestion issue in transmission with TCP is studied. Under the situation of different round trip time and multiple congested gateways, ECC (Explicit Congestion Control) algorithm is proposed to solve the congestion problem of TCP. The basic idea is to explicitly improve Congestion by adding mechanism at both end systems and gateways. Then study the tile congestion of Internet data transmission. Internet data transmission relies on end system mechanisms to keep Congestion. As the number of the users has been very large, this scheme has become vulnerable. It is required to deploy some congestion mechanism at gateways.

scholarly journals Development of an efficient mechanism for rapid protocols using NS-2 simulator

2020 ◽  
Vol 3 (1) ◽  
pp. 13-20
Author(s):  
Sarah N. Abdulwahid
Keyword(s):  
Congestion Control ◽  
High Speed ◽  
Control Algorithm ◽  
Transmission Control Protocol ◽  
Control Process ◽  
Congestion Avoidance ◽  
Network Simulator ◽  
Improvement Strategy ◽  
Slow Start ◽  
Congestion Control Algorithm

The delivered effort in this manuscript is grounded on NS-2 (The Network Simulator 2) to implement the congestion control process of classic TCP (Transmission Control Protocol), with new congestion control mechanism. In this paper, a novel congestion control algorithm is offered, which contains of slow-start and congestion avoidance mechanisms. The proposed slow-start algorithm assumes a duplicating and an interpolating approach to the congestion window (cwnd) for each increment instead of the exponential increment used by other TCP source variants such as Reno, Vega, Tahoe, Newreno, Fack, and Sack. Furthermore, the enhanced congestion avoidance algorithm is built by using an improved Additive Increase Multiplicative Decrease (AIMD) algorithm with multi TCP flow facility, to provide an enhanced congestion control algorithm with some valuable properties to improve TCP routine for high speed protocols. The improvement strategy based on merging of slow start, congestion avoidance mechanism that are used in TCP congestion control, to create a new AIMD algorithm with a new relationship between the pair parameters a and b. This paper is also involved in the creation of rapid agent in NS-2 models designed to identify the modified TCP and to configure the NS-2 platform. A fast TCP also includes an innovative scheme to slow the rapid start to help TCP to start faster through the high speed networks and also to postpone the congestion state as much as possible.

scholarly journals Development of an efficient mechanism for rapid protocols using NS-2 simulator

2018 ◽  
Vol 3 (1) ◽  
pp. 13-20
Author(s):  
Sarah N. Abdulwahid
Keyword(s):  
Congestion Control ◽  
High Speed ◽  
Control Algorithm ◽  
Transmission Control Protocol ◽  
Control Process ◽  
Congestion Avoidance ◽  
Network Simulator ◽  
Improvement Strategy ◽  
Slow Start ◽  
Congestion Control Algorithm

The delivered effort in this manuscript is grounded on NS-2 (The Network Simulator 2) to implement the congestion control process of classic TCP (Transmission Control Protocol), with new congestion control mechanism. In this paper, a novel congestion control algorithm is offered, which contains of slow-start and congestion avoidance mechanisms. The proposed slow-start algorithm assumes a duplicating and an interpolating approach to the congestion window (cwnd) for each increment instead of the exponential increment used by other TCP source variants such as Reno, Vega, Tahoe, Newreno, Fack, and Sack. Furthermore, the enhanced congestion avoidance algorithm is built by using an improved Additive Increase Multiplicative Decrease (AIMD) algorithm with multi TCP flow facility, to provide an enhanced congestion control algorithm with some valuable properties to improve TCP routine for high speed protocols. The improvement strategy based on merging of slow start, congestion avoidance mechanism that are used in TCP congestion control, to create a new AIMD algorithm with a new relationship between the pair parameters a and b. This paper is also involved in the creation of rapid agent in NS-2 models designed to identify the modified TCP and to configure the NS-2 platform. A fast TCP also includes an innovative scheme to slow the rapid start to help TCP to start faster through the high speed networks and also to postpone the congestion state as much as possible.

Network Congestion Control Algorithm Simulation Research Based on NS2

2015 ◽  
Vol 713-715 ◽  
pp. 2455-2461
Author(s):  
Wen Zhi Han
Keyword(s):  
Congestion Control ◽  
Control Problem ◽  
Control Algorithm ◽  
Network Simulator ◽  
Network Congestion ◽  
Network Environment ◽  
Linear Network ◽  
Simulation Research ◽  
Congestion Control Algorithm ◽  
Network Congestion Control

Network congestion control problem is one of the most key problems in network study. This paper studies different versions of TCP source port algorithm such as Tahoe, Reno, NewReno, SACK and Vegas, and makes simulation research on linear network and dumbbell network environment algorithm by using NS2 network simulator, and finally it concludes that: when there is no competition in the network, it is better to choose Vegas algorithm; when there is competition, choose Reno, NewReno, or Sack algorithm is more advisable.

scholarly journals Understanding of BBRv2: Evaluation and Comparison with BBRv1 Congestion Control Algorithm

IEEE Access ◽  
2021 ◽  
pp. 1-1
Author(s):  
Yeong-Jun Song ◽  
Geon-Hwan Kim ◽  
Imtiaz Mahmud ◽  
Won-Kyeong Seo ◽  
You-Ze Cho
Keyword(s):  
Congestion Control ◽  
Control Algorithm ◽  
Congestion Control Algorithm
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