VoDCast: Efficient SDN-based multicast for video on demand

Video constitutes the majority of traffic in ISP networks. The demand for more and higher quality videos is growing rapidly while network capacities are limited. Today, OTT video is mostly delivered over CDNs. For ISP-internal video such as IPTV channels, IP multicast provides an efficient delivery method. However, this does not scale for OTT videos due to their large number and their Zipf-distributed popularity. SDN-based multicast enables ISPs to deliver content based on efficient network-level multicast. However, so far this concept has not been applied for OTT Video-on-Demand (VoD) scenarios. To this end, this paper's contribution is threefold. First, a novel network-based multicast approach for OTT VoD delivery is presented, named VoDCast. Second, trace-based network simulations are designed and conducted. Third, the achievable bandwidth reduction and practicability of VoDCast is shown based on a two-week YouTube trace of a nation-wide mobile provider. VoDCast is able to decrease traffic volume and variance, while keeping network provider costs in terms of state overhead and state change low.