The Case for FEC Fueled TCP-like Congestion Control

This paper describes the design of a new rate and congestion controller (RCR) which employs FEC (forward error correction) support. The design follows the design principles of TCP but uses FEC to assure TCP-competitiveness. It is targeted primarily at one to many reliable bulk multicast data transfer. It shares bandwidth with other TCP flows fairly and is able to compensate drawbacks due to low responsiveness. The concept of RCR is validated by analytical and simulation results. The heuristic analysis is based on a new extended model for flows which implement a congestion control algorithm similar to TCP. Simulations and theoretical analysis for multicast as well as unicast setups show that already a very moderate level (some %) of redundancy suffices to strengthen a flow suffering from long delays and high loss probabilities.