Bit Indexed Explicit Replication (BIER) Problem Statement
Greg Shepherd, Andrew Dolganow, Arkadiy Gulko · 2016
There is a need to simplify network operations for multicast services. Current solutions require a tree-building control plane to build and maintain end-to-end tree state per flow, impacting router state capacity and network convergence times. Multi-point tree building protocols are often considered complex to deploy and debug and may include mechanics from legacy use-cases and/or assumptions which no longer apply to the current use-cases. When multicast services are transiting a provider network through an overlay, the core network has a choice to either aggregate customer state into a minimum set of core states resulting in flooding traffic to unwanted network end-points, or to map per-customer, per-flow tree state directly into the provider core state amplifying the network-wide state problem.