LayeredCast -A Hybrid Peer-to-Peer Live Layered Video Streaming Protocol

Abstract-Peer-to-Peer overlay networks are an attractive foundation for video streaming. However, live Peer-to-Peer media streaming systems face many challenges such as bandwidth heterogeneity, node churn, and selfish nodes. Although many tree based and mesh based streaming protocols have been proposed, each has its own drawbacks such as unreliability and unfairness in tree based and long startup delay and complex scheduling in mesh based protocols. In this paper, we propose a new video streaming protocol called LayeredCast main features of which are: 1) Hybrid: Drawbacks of the simple approaches are compensated using a hybrid of mesh and tree overlays. 2) Layered Video: Provides an adaptive scheme to enhance the video quality using a layered video codec for heterogeneous clients. 3) QoS: LayeredCast scheduling aims at moving complexity of Multi-Service network core to the network clients application layer, thus providing better QoS over simple regular networks. LayeredCast's tree network pushes the base layer to all peers while the enhancement layers and missing base layer segments are pulled over a mesh network by peers with extra bandwidth using a new data-driven scheduling scheme. We have evaluated the performance of LayeredCast on an innovative simulation framework. Simulation results verify better performance of LayeredCast in term of decodable video frames over CoolStreaming, especially when network resources are limited

Flow-level state transition as a new switch primitive for SDN

In software-defined networking, the controller installs flow-based rules at switches either proactively or reactively. The reactive ap-proach allows controller applications to make dynamic decisions about incoming traffic, but performs worse than the proactive one due to the controller involvement. To support dynamic applications with better performance, we propose FAST (Flow-level State Tran-sitions) as a new switch primitive for software-defined networks. With FAST, the controller simply preinstalls a state machine and switches can automatically record flow state transitions by match-ing incoming packets to installed filters. FAST can support a vari-ety of dynamic applications, and can be readily implemented with today’s commodity switch components and software switches