Background and Objectives: Nowadays, video hosting services receive and stream videos using standard protocols like Real-Time Messaging Protocol (RTMP). During the streaming process, video file streams are usually divided into small multi-second parts, and the player receives these parts instead of the whole file at once. Most of the streaming protocols are capable of adaptive streaming and tolerating faults like device failures, and link disconnections. Faults might affect the performance of live streaming in terms of packet loss, latency, jitter, and video quality. The software-defined networking paradigm has also gained momentum in enterprise networks due to its lower-cost management and better network utilization. However, full migration from the current networks to the SDN model is not practical.
Methods: The purpose of this study is to investigate the effectiveness of fault tolerance mechanisms of RTMP protocol on hybrid software-defined networks (SDN). In this paper, a practical and straightforward hybrid network architecture is proposed for gradual migration from traditional IP networks. Then, the performance of the RTMP protocol is compared for live video streaming on this network with different streams facing multiple failures.
Results: Our experiments show that network failure recovery time in SDN is directly depends on the video stream recovery time while in traditional networks, streams need to be buffered again and it takes another several seconds due to the long interruption time. We propose an equation to give a rough estimation of data loss in SDN network during failures based on our observations which helps us in comparisons. We also demonstrate the average switching time in the SDN networks is almost half of the switching time in traditional networks.
Conclusion: Our experiments proves, practically, video recovery time in SDN is less than a traditional network and has more correspondence with mechanisms of RTMP.
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