Adaptive Video Streaming, Multipath and Caching: Can Less Be More?
Vitalii Poliakov, Lucile Sassatelli, Damien Saucez · 2018
A prominent portion of the traffic carried by Internet Service Providers (ISPs) is delivered by Content Delivery Networks (CDNs), the vast majority being video traffic served over HTTP adaptive streaming. CDNs often deploy their own caches at ISPs in addition to the servers deployed in their own premises. The ability of user devices to use two network interfaces simultaneously is instrumental in improving the quality of access, and this is enabled by multipath (MP) transport protocols such as MPTCP. This ability however precludes the use of caches in access networks. This article investigates the operational points obtained from the combination of MP routing with different cache locations. By modelling the optimization problems of both actors, ISPs and CDN, and designing a simulation testbed using a mobile operator topology, we identify for which metrics (video bitrate, acceptance rate, link congestion) and in which conditions (cache locations, multipath enabled or not, type of video content), the new operational points are interesting. Under realistic video patterns, multipath allows to improve served bitrates over all request types by up to 40% depending on the load.