Impact of Buffer Structure for Mixed UDP and TCP Traffic in Routers with Very Small Buffers
Botao Bai, Jinyao Yan · Journal of Convergence Information Technology · 2013
The need for buffering is fundamental for packet switching networks. In recent years, studies show that the core router buffer sizes need only dozens of packets to meet acceptable link utilization. However, prior studies ignored whether buffer unit are structured in terms of packets or bytes. It made no much difference when only TCP traffic with the same packets size is considered in the previous studies. In this paper, we study the coexistence of real-time UDP and TCP traffic for routers with buffers of very small size. We keep the fraction of UDP traffic within 5-10% in bottleneck link. We simulate UDP traffic with Exponential source, Poisson source and real video streaming traces respectively and compare the performance of packet loss rate in different buffer unit structure. We found that the difference the buffer unit structure obviously impacts the loss performance of routers with very small buffers. When buffer unit are structured in terms of packets, the UDP packet loss rate is higher than the TCP packet loss rate. However, when buffer unit are structured in terms of bytes, the UDP packet loss rate is lower than the TCP packet loss rate.