AnySee

Elite

               
               
               
               
               
                Streaming systems focus on three metrics: startup delay, source-to-end delay, playback continuity.Two types of schemes based on intra-overlay optimization were proposed recently: tree-based overlays and mesh-based overlays. Tree-based protocols are simple, efficient, and scalable. To improve the stability of services, mesh-based protocols have been proposed, in which each peer can accept media data from multiple “parents” as well as providing services for multiple “children”.Due to the random selection algorithm, the quality of service cannot be guaranteed, such as the startup delay. Also, to decrease the impact of autonomy of peers on streaming services, very large buffer space, such as used in Coolstreaming, is necessary.AnySee faces the following challenges: (1) how to find paths with low delays, including source-to-end delay and startup delay, in a global P2P network; (2) how to maintain the service continuity and stability (decreasing the impact of interruption caused by peers leaving); (3) how to determine the frequency of optimization operations; (4) how to reduce the control overhead caused by the algorithm.component:single overlay manager, inter-overlay optimization manager, key node manager, buffer manager.
The clocks of all peers are synchronized based on NTP. Current implementation of NTP version 4.1.1 in public domain can reach the synchronization accuracy down to 7.5 milliseconds
Generally, each peer maintains one active streaming path set and one backup streaming path set.
When the number of backup streaming paths is less than a threshold, the inter-overlay optimization algorithm is called to find appropriate streaming paths in the global P2P network with the help of the mesh-based overlay. When one active streaming path is cut off due to its poor QoS or peer’s leaving, a new streaming path is selected from the backup set.
There are mainly two tasks for the inter-overlay optimization manager, including backup streaming path set management and active streaming path set management.
Same views:In intra overlay, construction is not globally optimal.Most of the existing protocols are tree based. Consequently, all leaf nodes fail to contribute any bandwidth or CPU cycles to the multicast trees.Several key issues, including efficient neighbor discovery, resource assignment, overlay construction and optimization, must be addressed.unclear views:peer P1 compares the distance between two paths, S→P1 and S→N1→ P1 . If the former length is larger, the link N1→P1 would be cut off and the direct path between S and P1 would be established. why reserve the larger but not the smaller?
               
               
               
               
               
               
               
               
               
               
               
               
               
               
               

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