PeerCDN: A novel P2P network assisted streaming content delivery network scheme

Providing scalable streaming media service over the internet is a demanding task nowadays, CDN(Content Delivery Network) and P2P are the main approaches while both have pros and cons. We propose a novel hybrid architecture - PeerCDN to combine the two approaches seamlessly with their inherited excellent features. PeerCDN is a two-layer streaming architecture. Upper layer is a server layer which is composed of original CDN servers including origin servers and replica servers. Lower layer consists of groups of clients who request the streaming services, each client is considered as a client peer in the group. Each group of client peers is led by the nearby replica server. Client peers contribute their resource through the coordination of the leader peer. The scheme uses a revised Kademlia-like protocol for peer-to-peer topology management and DHT for data retrieval. It constructs a topology-aware overlay network and results reduced jitter. PeerCDN makes best use of original investment and infrastructure. The service capacity is larger than traditional CDN system with the participation of the client peers. Also, the topology-aware overlay network restricts the unnecessary backbone bandwidth consuming during client peer sharing. The experiment result shows that PeerCDN has better features than the CDN and pure p2p approaches.