Seamless Multicast : an SDN-based architecture for continuous audiovisual transport

For audiovisual network operators, end-users satisfaction is a major issue. This is the case for TDF who operates a nationwide network in France whose main purpose is to carry Digital Terrestrial Television streams. Such audiovisual content is forwarded through multicast real-time streams which require continuity of service. Therefore, the main goal of this work is to define a new architecture to prevent impact during network healing time. The proposed architecture aims to use a pair of redundant multicast trees, and ensure their seamless resiliency. This architecture called “Seamless Multicast” takes advantage of the network-end equipment’s ability to receive and combine two identical streams, complete or not. The main contribution of this paper is the development and evaluation of an algorithm for the computation of a pair of multicast trees and the associated hitless deployment scheme. Implementation requires an Software-Defined Networking architecture, in which performance knowledge and bandwidth management are centralized in a controller. A proof of concept controller has been used for validation of the architecture’s global behaviour using a virtualized environment in multiple scenarios.