MPI-I-2003-1-008

The famous max-flow min-cut theorem states that a source node $s$ can send information through a network (V,E) to a sink node t at a rate determined by the min-cut separating s and t. Recently it has been shown that this rate can also be achieved for multicasting to several sinks provided that the intermediate nodes are allowed to reencode the information they receive. We give polynomial time algorithms for solving this problem. We additionally underline the potential benefit of coding by showing that multicasting without coding sometimes only allows a rate that is a factor Omega(log |V|) smaller.