DynaPeer: A Dynamic Peer-to-Peer Based Delivery Scheme for VoD Systems

摘要

Supporting Video-on-Demand (VoD) services in Internet is still a challenging issue due to high bandwidth requirement of multimedia contents and additional constraints imposed by such environment: higher delays and jitter, network congestion, non-symmetrical clients’ bandwidth and inadequate support for multicast communications. This paper presents DynaPeer, a peer-topeer VoD delivery policy designed for Internet environment. Our design defines a Virtual Server, which is responsible for establishing a group of peers, enabling service for new client requests by aggregating the necessary clients’ resources. Virtual Server operates in both unicast and multicast environments, thereby improving system performance. To demonstrate the effectiveness of DynaPeer, we have developed an analytical model to evaluate its performance, understood as the server-load reduction due to request service distributed among peers. We conducted a performance comparison study of our proposal with classic unicast, multicast (Patching) and other P2P delivery schemes, such as Pn2Pm, Chaining and Promise, improving their performance by 45%, 59%, 74% respectively, even when taking into account Internet constraints.