On the HTTP segment streaming potentials and performance improvements

• Main Author: Kupka, Tomas
• Format: Dissertation
• Language: English

Video streaming has gone a long way from its early years in the 90’s. Today, the prevailing technique to stream live and video on demand (VoD) content is adaptive HTTP segment streaming as used by the solutions from for example Apple, Microsoft, and Adobe. The reasons are its simple deployment and management. The HTTP infrastructure, including HTTP proxies, caches and in general Content Delivery Networks (CDNs), is already deployed. Furthermore, HTTP is the de facto standard protocol of the Internet and is therefore allowed to pass through most firewalls and Network Address Translation (NAT) devices. The goal of this thesis is to investigate the possible uses of adaptive HTTP segment streaming beyond the classical linear streaming and to look at ways to make HTTP servers dealing with HTTP segment streaming traffic more efficient. In addition to the deployment and management benefits, the segmentation of video opens new application possibilities. In this thesis, we investigate those first. For example, we demonstrate on the fly creation of custom video playlists containing only content relevant to a user query. Using user surveys, we show, that it not only saves time to automatically get playlists created from relevant video excerpts, but the user experience increases significantly as well. However, already the basic capabilities of HTTP segment streaming, i.e., streaming of live and on demand video, are very popular and are creating a huge amount of network traffic. Our analysis of logs provided by a Norwegian streaming provider Comoyo indicates that a substantial amount of the traffic data must be served from places other than the origin server. Since a substantial part of the traffic comes from places other than the origin server, it is important that effective and efficient use of resources not only takes place on the origin server, but also on other, possibly HTTP segment streaming unaware servers. The HTTP segment streaming unaware servers handle segment streaming data as any other type of web data (HTML pages, images, CSS files, javascript files etc.). It is important to look at how the effectiveness of data delivery from this kind of servers can be improved, because there might be potentially many "off the shelf" servers serving video segments (be it a homemade solution or an HTTP streaming-unaware CDN server). In general, there are three possible places to improve the situation: on the server, in the network and on the client. To improve the situat