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 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.

An Improved Congestion Control Mechanism Based on Mobile Agent for Wireless Sensor Networks

2014 ◽  
Vol 519-520 ◽  
pp. 1239-1242
Author(s):  
Xiao Hu Yu
Keyword(s):  
Wireless Sensor Networks ◽  
Sensor Networks ◽  
Congestion Control ◽  
Mobile Agent ◽  
Mobile Agents ◽  
Control Mechanism ◽  
Wireless Sensor ◽  
Delivery Ratio ◽  
Routing Table ◽  
Congestion Control Mechanism

An improved congestion control mechanism based on mobile agent for wireless sensor networks is proposed, which includes node-level congestion and link-level congestion control. The formers congestion information is collected and distributed by mobile agents (MA). When mobile agent travels through the networks, it can select a less-loaded neighbor node as its next hop and update the routing table according to the nodes congestion status. Minimum package of node outgoing traffic was preferentially transmitted in the link-level congestion. Simulation result shows that proposed mechanism attains high delivery ratio and throughput with reduced delay when compared with the existing technique.

An Extended Throughput Model of SCTP with Scalab Congestion Control

2011 ◽  
Vol 219-220 ◽  
pp. 1656-1659
Author(s):  
Chang Hua Liu ◽  
Cao Yuan
Keyword(s):  
Congestion Control ◽  
Analytical Model ◽  
Control Mechanism ◽  
Transmission Protocol ◽  
Local Networks ◽  
Ip Address ◽  
Stream Control Transmission Protocol ◽  
Throughput Model ◽  
Stream Control ◽  
Congestion Control Mechanism

The technologies of Wireless local networks and cellular network are very popular and more and more service under the integrated heterogeneous environment. Stream Control Transmission Protocol (SCTP) is considered as an ideal to support the communication between them by enabling a mobile client to freely switch the IP address in different networks. In this paper, we propose an extended analytical model for SCTP which consider the congestion window and scalable of congestion control mechanism. A great advantage of our model is that establishing a relationship between the throughput and congestion control mechanism. Furthermore, the analytical model provides a useful tool to improve congestion control mechanism of SCTP.

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