scholarly journals A novel congestion control mechanism for multicast real-time connections

1999 ◽  
Vol 22 (1) ◽  
pp. 56-72 ◽  
Author(s):  
Jau-Hsiung Huang ◽  
Chun-Chuan Yang ◽  
Nai-Cheng Fang
Keyword(s):  
Congestion Control ◽  
Real Time ◽  
Control Mechanism ◽  
Congestion Control Mechanism

A Dynamic Approach to Estimate Receiving Bandwidth for WebRTC

2016 ◽  
Vol 7 (3) ◽  
pp. 17-33
Author(s):  
Razib Iqbal ◽  
Shervin Shirmohammadi ◽  
Rasha Atwah
Keyword(s):  
Congestion Control ◽  
Real Time ◽  
Control Mechanism ◽  
Task Force ◽  
Round Trip Time ◽  
Round Trip ◽  
Dynamic Approach ◽  
Trip Time ◽  
Proposed Model ◽  
Congestion Control Mechanism

Web Real-Time Communication (WebRTC), drafted by the World Wide Web Consortium (W3C) and Internet Engineering Task Force (IETF), enables direct browser-to-browser real-time communication. As its congestion control mechanism, WebRTC uses the Google Congestion Control (GCC) algorithm. But using GCC will limit WebRTC's performance in cases of overusing due to using a fixed decreasing factor, known as alpha (a). In this paper, the authors propose a dynamic alpha model to reduce the receiving bandwidth estimate during overuse as indicated by the overuse detector. Using their proposed model, the receiver can more efficiently estimate its receiving rate in case of overuse. They implemented their model over both unconstrained and constrained networks. Experimental results show noticeable improvements in terms of higher incoming rate, lower Round-Trip Time, and lower packet loss compared to the fixed alpha model.

scholarly journals Analisis Kualitas VoIP pada SCTP Menggunakan ECN dan AQM

2015 ◽  
Vol 9 (2) ◽  
pp. 121
Author(s):  
La Surimi ◽  
Reza Pulungan
Keyword(s):  
Congestion Control ◽  
Real Time ◽  
Control Mechanism ◽  
Data Transfer ◽  
Reliable Data ◽  
Network Simulator ◽  
Independent Replication ◽  
Congestion Control Mechanism ◽  
Replication Technique

AbstrakVoIP merupakan aplikasi real time yang kualitasnya sangat tergantung pada delay dan jitter, yang mana hal ini sulit dipenuhi oleh protokol yang bersifat reliable dan memiliki congestion control seperti TCP. Di sisi lain penggunaan UDP yang tidak memiliki congestion control menyebabkan peluang terjadinya congestion pada jaringan sangat besar. Penggunaan SCTP sebagai protokol alternatif juga belum mampu mengakomodasi kekurangan TCP dan UDP. Beberapa hasil penelitian menunjukkan perlu adanya perbaikan ataupun modifikasi pada mekanisme congestion control yang dimiliki oleh SCTP. Penggunaan mekanisme ECN dan AQM  pada beberapa penelitian menunjukkan bahwa kedua mekanisme ini dapat menurunkan delay dan jitter. Penelitian ini melakukan pengujian terhadap kualitas VoIP di atas SCTP yang menggunakan ECN dan AVQ pada network simulator NS2. Hasil simulasi menunjukkan bahwa penggunaan mekanisme ECN dan AVQ pada protokol SCTP menghasilkan kualitas VoIP yang lebih baik pada kondisi jaringan yang tidak ideal (high Latency low Bandwidth dan low Latency low Bandwidth dari pada penggunaan protokol SCTP tanpa menggunakan mekanisme ECN dan AVQ. Penelitian ini juga melakukan perbandingan nilai MOS panggilan VoIP SCTP yang menggunakan ECN dan AVQ dengan nilai MOS panggilan VoIP yang menggunakan protokol TCP dan UDP. Hasilnya SCTP dengan ECN dan AVQ mengungguli TCP namun belum dapat mengungguli UDP. Kata kunci— VoIP, SCTP, ECN, AQM,AVQ. AbstractVoIP is the real time applications that are highly dependent on the quality of  delay and jitter, which it is difficult to be met by protocol that has reliable data transfer feature and  congestion control such as TCP. On the other hand the use of UDP that has no congestion control make chance of causing congestion in the network is very large. The use of SCTP as an alternative protocol was also not able to accommodate the weaknesses of TCP and UDP. Some research shows that repairs or modifications to the SCTP congestion control mechanism is needed.The Use of ECN and AQM in some studies show that these two mechanisms can reduce delay and jitter. This study tested the quality of VoIP over SCTP with ECN and AVQ, in NS2. Simulations carried out by independent replication technique, and the results showed that ECN and AVQ can increase the value of MOS VoIP calls significantly in non ideal network scenarios. This study also did comparison of SCTP MOS that uses ECN and AVQ with MOS values VoIP using TCP and UDP. The result showed that SCTP with ECN and AVQ outperform TCP but can not surpass UDP yet. Keywords— VoIP, SCTP, ECN, AQM,AVQ. 

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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