Efficient loss recovery in application overlay stored media streaming
Zhi-ping Xie, Gengsheng Zheng, Guiming He · 2005
As the Internet does not widely support Internet protocol multicast, and content distribution networks are costly, application overlay has emerged as an alternative for deploying large scale streaming systems. Loss recovery in such architecture is a great challenge because of the correlation of packet losses results from the relaying nature, the variation of accumulated loss rates, and the dynamics of overlay structure, which is inevitable. Since each overlay node is capable of buffering a certain length of media data it has received, and there exists a temporal dependency between the buffers of nodes along a transmitting path, it is highly desirable to make full use of this buffering capability to carry out loss recovery. To this purpose, a retransmission-based approach is proposed in this paper. First, packet losses at a node are classified into two categories according to whether they can be repaired from the immediate upstream node, then, by making upstream nodes propagate loss information downstream, the proposed scheme enables each node efficiently recognize the nature of the loss it detects, and accordingly determine appropriate repair source, thus suppresses unnecessary retransmission requests. The proposed scheme is supported by theoretical analysis of the temporal dependency between overlay nodes, and its performance is verified by experimental results.