• K V Suresha

Abstract- Nowadays, by accelerated growth of number of devices connecting to the Internet and emergence of IoT, the internet traffic is rapidly increasing. In these environments the probability of congestion is constantly rising. In the traditional networks, the end devices are responsible for controlling the congestion, but since these devices do not have a global and comprehensive view of the network, they cannot predict the congestion to prevent the packet loss. Hence the overall network throughput is reduced. this paper proposes a survey on congestion control mechanism in SDN. Telecommunication, Computer Networks and both wired and wireless communications including the Internet, are being designed for fast transmission of large amounts of data, for which Congestion Control is very important. Without proper Congestion control mechanism, the congestion collapse of such networks would become highly complex. Congestion control for streamed media traffic over network is a challenge due to the sensitivity of such traffic towards. This challenge has motivated the researchers over the last decade to develop a number of congestion control protocols and mechanisms that suit the traffic and provides fair maintenance for both unicast and multicast communications. This paper gives out a brief survey of major congestion control mechanisms, categorization characteristics, elaborates the TCP-friendliness concept and then a state-of-the-art for the congestion control mechanisms designed for network. The paper points the pros and cons of the congestion control mechanism, and evaluates their characteristics. To compensate packet loss some protocols, use fast retransmission scheme but suffer problem of Congestion collapse. Congestion collapse means the bandwidth is available but the network becomes under-utilize. When a network is in such condition, since the network is under-utilizing and the demand is high, both lead to worst throughput. The network in this situation experience high level of loss and delayed packet. This results in need for better algorithms, protocol implementations scheme(s) and efficient network devices with sufficient space (storage), because the reason behind the Network Congestion problem lies in transport protocol implementations. The obvious looking way to implement a Protocol sometimes results in wrong response to the network. The algorithms in this category are rooted in the idea that the condition of packet conservation must not violet. This paper is a survey of congestion control algorithms in packet switched networks.

Keywords- Congestion. Congestion Control. TCP-Friendliness, Goals, and Metrics of Congestion Control and UDP Traffic.

"A Survey on Congestion Control and Congestion Control Mechanism-A Study", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.8, Issue 2, page no.218-226, February-2021, Available :http://www.jetir.org/papers/JETIR2102327.pdf

"A Survey on Congestion Control and Congestion Control Mechanism-A Study", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.8, Issue 2, page no. pp218-226, February-2021, Available at : http://www.jetir.org/papers/JETIR2102327.pdf