Congestion Window Scaling Method to Optimize Delay in TCP/IP

Abstract

TCP (Transmission Control Protocol) is a protocol of layer four (Transport Layer), and IP (Internet Protocol) is in the Network Layer (Layer 3) of the OSI Model. The TCP protocol is the most used of the network applications on the Internet. TCP performance is strongly influenced by its congestion control algorithms that limit the amount of transmitted traffic based on the estimated network capacity and utilization. TCP is a connection-oriented protocol which guarantees the sent packets to the destination in accurate order whereas UDP is an unreliable/connectionless protocol which does not guarantee that the sent messages would reach the destination. A TCP connection is used to control packet sizes, the rate of data exchange, flow control and network congestion. Unfortunately, congestion/network overload happens in the TCP connection which affects the rate of data flow, loss in packets transmitted, packet transmission delay and delayed acknowledgment. In this paper, a method to scale the congestion window on the sender and receiver to optimize the delay of transmission in TCP in order to reduce the congestion rate is proposed. The proposed congestion control algorithm enables a sender to optimize and initialize the congestion window before transmitting packets. The proposed method is evaluated by simulating the transmission in Network Simulation 3 (NS3).