Approaches toward Maintaining Bi-connectivity for Resilience in Overlaid Multicasting.

In Application layer multicast (ALM) (also called Overlay Multicast), multicast-related functionalities are moved to end-hosts. The key advantages, overlays offers, are flexibility, adaptability and ease of deployment [1]. Application layer multicast builds a peer-to-peer (P2P) overlay topology consisting of end-to-end unicast connections between end-hosts. End users self organize themselves into logical overlay networks for efficient data delivery. The major concern in designing ALM protocol is how to build and maintain a topology, to route data efficiently and reliably. We propose here a two-fold dynamic overlay tree construction and maintenance scheme in which a mesh-like topology is first built, and on top of it, a single or multiple data delivery tree(s) are built. While forming the mesh, it is ensured that two node disjoint paths are maintained between every possible pair of nodes. The overlay tree is built such that every host gets data feeds via two different paths. A fully dynamic algorithm is run over the overlay topology to insert new links to maintain biconnectivity while deleting the redundant links.