  In this work, we formulate and study a data dissemination problem, which can
be viewed as a generalization of the index coding problem and of the data
exchange problem to networks with an arbitrary topology. We define $r$-solvable
networks, in which data dissemination can be achieved in $r > 0$ communications
rounds. We show that the optimum number of transmissions for any one-round
communications scheme is given by the minimum rank of a certain constrained
family of matrices. For a special case of this problem, called bipartite data
dissemination problem, we present lower and upper graph-theoretic bounds on the
optimum number of transmissions. For general $r$-solvable networks, we derive
an upper bound on the minimum number of transmissions in any scheme with $\geq
r$ rounds. We experimentally compare the obtained upper bound to a simple lower
bound.
