| dc.description.abstract | In mesh networks, the sender machine is connected to the receiver machine via multiple paths. Efficient transmissions along these paths require proper link choice so as to quickly deliver the packets the destination. Poor link selection can lead to overutilization of some links while the other redundant links remain underutilized. Over-utilized links experience heavy congestions under peak hours. The transmission control protocol (TCP) employs congestion control algorithms to prevent transmitters from overloading the network with data. These algorithms include slow start, congestion avoidance, fast retransmit and fast recovery. The slow start algorithm is utilized during the initial communication phase while congestion avoidance, fast retransmit and fast recovery are reactionary algorithms one packet loss is detected. This paper aimed to analyze the behavior of TCP under these congestion control algorithms in wired mesh networks. The dimensions that were used for this analysis included three-way handshake, packet loss, duplicate acknowledgements, segment retransmissions, recovery, I/O plots and time-sequence plots. The objective of this study was to practically understand how the TCP protocol detects and handles network congestions in mesh networks. To achieve this objective, an experimental research design was employed. It involved the practical design of experimental setups that were used to collect data that was analyzed to provide an explanation of the TCP congestion control mechanisms. The results obtained indicate that the TCP first carries out a three handshake before data transmission can take place. It was also observed that the receipt of three duplicate acknowledgements is interpreted by TCP to be packet loss caused by network congestion. Moreover, it was established that TCP initiates fast retransmit and fast recovery when packet loss is detected. The contribution of this paper lies in the fact that it provided a practical understanding of how TCP detects and reacts to mesh network congestion, a concept that is critical to network administrators in their quest for packet loss prevention over the TCP architecture. Towards the end of the paper, suggestions for developing better ways of congestion handling in mesh networks by use of round trip times | en_US |
