scholarly journals A Model-based Scalable Reliable Multicast Transport Protocol for Satellite Networks

2017 ◽  
Vol 1 (1) ◽  
pp. 24
Author(s):  
Prawit Chumchu ◽  
Roksana Boreli ◽  
Aruna Seneviratne
Keyword(s):  
Congestion Control ◽  
Error Control ◽  
Forward Error Correction ◽  
Transmission Control Protocol ◽  
Window Size ◽  
Satellite Networks ◽  
Transport Protocol ◽  
Reliable Multicast ◽  
Auto Repeat Request ◽  
Control Part

In this paper, we design a new scalable reliable multicast transport protocol for satellite networks (RMT). This paper is the extensions of paper in [18]. The proposed protocoldoes not require inspection and/or interception of packets at intermediate nodes. The protocol would not require anymodification of satellites, which could be bent-pipe satellites or onboard processing satellites. The proposed protocol is divided in 2 parts: error control part and congestion control part. In error control part, we intend to solve feedback implosion and improve scalability by using a new hybrid of ARQ (Auto Repeat Request) and adaptive forward error correction (AFEC). The AFEC algorithm adapts proactive redundancy levels following the number of receivers and average packet loss rate. This leads to a number of transmissions and the number of feedback signals are virtually independent of the number of receivers. Therefore, wireless link utilization used by the proposed protocol is virtually independent of the number of multicast receivers. In congestion control part, the proposed protocol employs a new window-based congestion control scheme, which is optimized for satellite networks. To be fair to the other traffics, the congestion control mimics congestion control in the wellknown Transmission Control Protocol (TCP) which relies on “packet conservation” principle. To reduce feedback implosion, only a few receivers, ACKers, are selected to report the receiving status. In addition, in order to avoid “drop-to-zero” problem, we use a new simple wireless loss filter algorithm. This loss filter algorithm significantly reduces the probability of the congestion window size to be unnecessarily reduced because of common wireless losses. Furthermore, to improve achievable throughput, we employ slow start threshold adaptation based on estimated bandwidth. The congestion control also deals with variations in network conditions by dynamically electing ACKers.

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.

scholarly journals Improving Congestion Control of TCP for Constrained IoT Networks

Sensors ◽  
2020 ◽  
Vol 20 (17) ◽  
pp. 4774
Author(s):  
Chansook Lim
Keyword(s):  
Congestion Control ◽  
Transmission Control Protocol ◽  
Window Size ◽  
Preliminary Test ◽  
Transport Layer ◽  
Network Simulator ◽  
Duty Cycling ◽  
Hidden Terminal ◽  
Grid Topology ◽  
Retransmission Timeout

For smooth integration with middleboxes on the Internet, TCP (Transmission Control Protocol) is favorably considered as a transport-layer protocol for IoT (Internet of Things) networks. In constrained networks, TCP tends to perform well with a small window size. For example, the uIP (micro IP) TCP/IP stack sets the TCP window size to one segment by default. In such a case, managing the retransmission timer is a primary approach to congestion control. In this paper, we examine the congestion control mechanism of TCP in the uIP stack using grid topology networks. In the preliminary test using the Cooja network simulator, the results show that the original uIP TCP causes lots of retransmissions when a radio duty cycling mechanism such as ContikiMAC is used. One main reason is that, once retransmission is deemed to be necessary, the original uIP TCP sets the retransmission timer based on the fixed RTO (retransmission timeout) before performing a retransmission. Since ContikiMAC may cause large RTT (round-trip time) variations due to the hidden terminal problem, the retransmission timer based on the fixed RTO value may cause lots of retransmissions. To address the problem, we propose a new scheme for managing the retransmission timer which adopts the notion of weak RTT estimation of CoCoA, exponential backoffs with variable limits, and dithering. Simulation results show that our proposed scheme reduces retransmissions while enhancing throughput and fairness when an RDC (radio duty cycling) mechanism is used.

scholarly journals Analisis Pengaruh Ukuran Window Pada Pengendali Kemacetan di SCTP Menggunakan Fitur Multihoming

2015 ◽  
Vol 9 (2) ◽  
pp. 133
Author(s):  
Agus Halid ◽  
Reza Pulungan
Keyword(s):  
Congestion Control ◽  
Packet Loss ◽  
Transmission Control Protocol ◽  
Window Size ◽  
Transmission Protocol ◽  
Transmission Control ◽  
User Datagram Protocol ◽  
Stream Control Transmission Protocol ◽  
Control Protocol ◽  
Stream Control

AbstrakStream Control Transmission Protocol (SCTP) merupakan protokol yang mirip dengan Transmission Control Protocol (TCP) dan User Datagram Protocol (UDP). SCTP merupakan protokol yang bersifat reliable dan connectionless. Protokol ini memiliki kemampuan multistreaming dan multihoming dalam melakukan transmisi data. Penelitian ini merupakan pemodelan terhadap SCTP menggunakan simulator OPNET yang dapat menjadi akselerasi bagi peneliti dalam bidang jaringan. SCTP pada simulator dibangun dengan melakukan modifikasi terhadap TCP. Pemodelan dimulai dengan membangun skenario jaringan dan menentukan bandwidth pada jalur yang akan dilewati oleh paket data.Modifikasi ukuran window dalam penelitian ini menggunakan nilai 1 MMS, 2 MMS hingga 10 MMS pada pengendali kemacetan. Tujuannya adalah untuk melihat pengaruh modifikasi ukuran window terhadap nilai packet loss, delay dan throughput. Hasil pengukuran memperlihatkan bahwa nilai throughput tertinggi terdapat pada Skenario Kedua sebagaimana diperlihatkan pada Tabel 6.4 dengan nilai throughput sebesar 433.566,0244 bit/s. Penggunaan ukuran window dalam pengendali kemacetan dimaksudkan untuk menghindari banjir data pada sisi endpoint yang dapat menyebabkan packet loss. Kata kunci—Pengendali kemacetan, throughput, delay, packet loss, ukuran window, multihoming, SCTP  Abstract Stream Control Transmission Protocol (SCTP) is a protocol that is similar to the Transmission Control Protocol (TCP) and User Datagram Protocol (UDP). SCTP is a protocol that is both reliable and connectionless. This protocol has the ability multistreaming and multihoming in the transmit data.This research is the modeling of the SCTP using OPNET simulator that can be accelerated for researchers in the field of networking. SCTP on the simulator was built to perform modifications to TCP. Modeling starts with building a network scenarios and determine the bandwidth on the path that will be passed by data packets.Modification of window size in this research using 1 MMS, 2 MMS up to 10 MMS on congestion control. The aim is to disclose the effect of modification of the window size to the value packet loss, delay and throughput. The measurement results show that the throughput rate is highest in the Second Scenario as shown in Table 6.4 with throughput value of 433.566,0244 bits/s. Using window size in congestion control is intended to prevent a flood of data on the endpoint that can lead to packet loss. Keywords—Congestion control, throughput, delay, packet loss, window size, multihoming, SCTP 

scholarly journals Reactivity Enhancement of Cooperative Congestion Control for Satellite Networks

2020 ◽  
Author(s):  
Adrien Thibaud ◽  
Julien Fasson ◽  
Fabrice Arnal ◽  
Renaud Sallantin ◽  
Emmanuel Dubois ◽  
...  
Keyword(s):  
Congestion Control ◽  
Satellite Networks
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