Improved dual-forest for multicast protection

To provide fault-tolerance for multicast connections, different techniques of protection are developed. These techniques can be classed into reactive and pro-active approaches. Reactive approaches can have long recovery latency which is undesirable for many types of applications such as the real time ones. In this paper, we focus on the multicast pro-active fault-tolerance schemes. One of the promising protection techniques is the dual-tree protection which is efficient to cope with single link failure but which cannot deal with node failures suitably. In this paper, we present an improved solution using a dual-forest for multicast protection. Our proposition provides three improvements to traditional dual-tree protection. The first one concerns the capability to bypass both single link and node failures in a suitable and quick manner. The second increases the level of protection with the use of a forest as backup instead of a tree. The last permits the cost optimization of the dual-forest and of the delivery tree after recovery. Simulation experiments show that the improved dual-forest scheme has better protection rate and causes less tree cost increase after recovery than the path-protection scheme