  A generic network flow model of transport (of relevance to information
transport as well as physical transport) is studied under two different control
protocols. The first involves information concerning the global state of the
network, the second only information about nodes' nearest neighbors. The global
protocol allows for a larger external drive before jamming sets in, at the
price of significant larger flow fluctuations. By triggering jams in
neighboring nodes, the jamming perturbation grows as a pulsating core. This
feature explains the different results for the two information protocols.
