File-Stream Distribution Application on Software-Defined Networks (SDN)

In a meteorology data-distribution application, streams of files are served to hundreds of receivers every day on unicast TCP connections. Software Defined Networking (SDN) offers a more scalable solution in which a rate-guaranteed Layer-2 multipoint virtual topology can be provisioned to have switches perform Ethernet-frame multicasting to support this application. A characterization of the file streams shows that file sizes and file inter-arrival times are both right skewed. The objective of this work is to design an algorithm for determining the rate of the Layer-2 multipoint virtual topology, and the size of the sending-host buffer, based on traffic characteristics of the file streams and performance requirements. Furthermore, the traffic characteristics are not exactly the same from day-to-day. An empirical method is proposed to determine the ideal rate and buffer size based on a day´s traffic, which are then used along with the current rate and buffer size in an Exponential Weighted Moving Average (EWMA) scheme to determine the rate and buffer size for the next day. Our method was evaluated using metadata obtained for the top five file-streams of this meteorological data distribution, and found to be effective.