Reliable Multi-Path Routing Schemes for Voice over Packet Networks

Applying forward error correction (FEC) in offline streaming with large buffering time dramatically improves the quality and performance of communications under challenging network conditions. However real-time streaming puts hard restrictions on the buffer size and therefore does not allow FEC to compensate for long link failures on single path routes. However, multi-path routing, orthogonal to buffering, can 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 a simple multi-path solution and evolving toward more reliable and secure schemes. The friendliness of a particular multi-path routing scheme is rated by a measure called Redundancy Overall Requirement (ROR), which is proportional to the total amount of the FEC codes required for combating the individual failures of all links in the multi-path route. A dozen of capillary routing layers, built on several hundreds of network samples obtained from a random walk wireless Mobile Ad-Hoc Network (MANET), are rated with ROR. We show that the overall amount of FEC codes decreases substantially as the spreading of the routing grows.