Failure Recovery Redundancy Overall Requirement

Forward Error Correction (FEC) is very efficient for off-line streaming with large buffering time, but real-time streaming puts hard restrictions on the buffer size making FEC inefficient for combating long link failures on single path routes. Multi-path routing, orthogonal to buffering, can however make FEC effective also for real-time streaming. For this purpose we introduce a capillary routing algorithm offering layer by layer a wide range of multi-path routing topologies starting from simple solutions and evolving toward reliable and secure routing schemes with highly developed path diversity. The friendliness of a particular multi-path routing is rated by the overall amount of FEC redundancy required for combating the non-simultaneous failures of all links in the multi-path route. We rated the friendliness of a dozen of capillary routing layers, built on several hundreds of network samples obtained from a random walk wireless Mobile Ad-Hoc Network (MANET). The overall requirement in redundant FEC codes decreases substantially as the spreading of the routing grows.