Abstract: A Packet switched networks consist of TCP and UDP traffic. In Recent years most of the internet traffic is open loop traffic i.e., UDP. The increase in streaming services like music, movies, video games and VOIP have in-turn increased the UDP traffic in a packet-switched network. A router is a device which forwards packets between source and the destination. The buffer is a small storage space which will store the incoming packets during the Transmission. The buffer size in routers play a vital role in transmitting packets from source to destination. An optimal buffer size will reduce the congestion and increase the throughput of a bottleneck link where else the opposite will lead to buffer overflow or underflow which will leads to packets loss and lower throughput etc. In previous studies researchers only considered TCP Traffic and ignored the UDP. We found that it is necessary to analyse both TCP and UDP so that we can present buffer sizes for routers which will increase throughput for open and closed loop traffic and also have minimal packet loss. Our results are confirmed with Network Simulator – 2.

Keywords: Buffer size, Network simulation, Throughput.