A Churn-Tolerant P2P CDN at the Edge for Video Content Delivery

To meet the demands of an ever increasing number of users wishing to watch video-based content over the Internet, the idea of content delivery network (CDN) at the edge has been advocated. Earlier, we have proposed an architecture using technologies such as DHT-based P2P overlays, software-defined networking (SDN), and dynamic adaptive streaming over HTTP (DASH) to provide P2P CDN at the edge within the enterprise domain. However, under moderate to heavy churn of peers, our implementation failed to provide acceptable QoS. We identified that the major reason behind the unacceptable QoS under churn is due to a complex relationship among HTTP keep-alive timeout, TCP keep-alive timeout and video chunk size which leads to late notification of the event of peer leaving. This results in frequent stalls and relatively longer stall durations affecting the QoS badly. In this paper, we present our SDN-based churn-tolerant approach.