Combined Network and Erasure Coding Proactive Protection for Multiple Source Multicast Sessions

Due to the increase in the density and multitude of online real time applications involving group communication which require a certain degree of resiliency, proactive protection of multicast sessions in a network has become prominent. The backbone network providing such a service hence needs to be robust and resilient to failures. In this thesis, we consider the problem of providing fault tolerant operation for such multicast networks that have multiple sources and need to deliver data to pre-defined set of destinations. The data is assumed to be delivered in a highly connected environment with a lot of nodes, e,g., a dense wireless network. The advent of network coding has enabled us to look at novel ways of providing proactive protection. Our algorithm combines network and erasure coding to present a scheme which can tolerate predefined amount of failures in the paths from the sources to the destinations. This is accomplished by introducing redundancy in the data sent through the various paths. Network coding seeks to optimize the resource usage in the process. For sources that cannot meet the constraints of the scheme, protection is provided at the cost of reduced throughput

An Architecture for Scalable, Efficient and Fast Fault-Tolerant Multicast Provisioning

Providing fault-tolerance to multicast connections is an important and challenging requirement of future networks. The existing techniques for fault-tolerant multicast can be grouped into on-demand and pre-planned approaches. On-demand approaches can have long recovery latency. For faster recovery, pre-planned approaches have been developed. However, in this type of approaches, the overhead cost is generally very high, especially when there is a large number of simultaneous groups in the network. In this article, we first provide an overview of the current multicast fault-tolerance methods. In addition, we propose a novel architecture called Aggregated MPLS-based Fault-Tolerant Multicast (AMFM) for scalable, efficient and fast fault-tolerant multicast provisioning. AMFM falls in the category of preplanned approaches. Using the concept of aggregated multicast [5], AMFM facilitates fault-tolerance in a very elegant way: it reduces the protection cost significantly; it is scalable to large numbers of groups; and it can also recover failure in a very fast manner. This article describes the architecture of AMFM and provides a feasibility check from an implementation point of view. We also conduct experiments to evaluate the performance of AMFM and show it can provide fault-tolerance in a scalable fashion