Congestion Control for Wired Network

Congestion Control for Wired Network

Background of Congestion Management

Network congestion is a condition in which an increase in traffic flow causes an overall slowdown of the network system. Incoming frames in the buffers of the switches are rejected in this case. Network congestion management is a management activity which aims to ensure that maximum numbers of phone calls are connected to the destination (Krishnan and Mayhew, 2004). Congestion management is a feature of the packet-switched networks. The purpose of congestion management is to prevent and limit the phenomena of congestion that can occur in the nodes of internal switching of the transport network through a control of transmission by the sender and recipient of a communication.

It can be implemented in the link layer, network layer, and transport layer or in the level applications. In packet networks, the packets send a large amount of different devices, such as routers, switches and bridges (Floyd and Jacobson, 1993). These devices and the links that interconnect them, have processing capability and transmission limited, which may lead, in many cases, in situations of congestion, i.e. in situations in which these nodes are not capable of sorting all the traffic offered input from various connections between users causing packet loss or excessive delays.

The congestion management allows therefore improving network performance by avoiding packet losses and limiting the delay due to retransmissions of lost packets. It differs from the flow control that is instead a control mechanism of transmission typically dictated by the ability of the recipient and exclusively designed to not exceed the capacity of processing and storage of the receiver only by the sender. To support congestion management, users can highlight some overloaded network components and thus make the network unusable, unless appropriate measures are not taken. Connection-oriented protocols such as TCP monitor in general the number of lost data packets and delays in order to adjust the transmission speed adequately.

Background of Quality of Service

Quality of Service (QoS) is the transmission technology that ensures a certain amount of information at a given time throughout. Quality of service is the ability to provide good service. It is especially important for certain applications such as streaming video or voice (Floyd and Jacobson, 1993). The wireless environment is very hostile to measures of quality of service due to its variability over time, as it can show a quality zero at some instant of time. This implies ...