Resumen
A method for operating a network, wherein said network (1) includes a plurality of network nodes (5), and wherein traffic flows - real flows - are routed from network node (5) to network node (5) within said network (1), is characterized in the steps of introducing in said network (1) a virtual source node (2) and a virtual destination node (3), and creating virtual links between said virtual source node (2) and each of said network nodes (5) as well as between each of said network nodes (5) and said virtual destination node (3), introducing a number k of virtual flows originating at said virtual source node (2) and terminating at said virtual destination node (3) in such a way that a network node (5) can either route a virtual flow or any real flow, formulating an IP (Integer Programming) problem that aims at maximizing the number of routed flows - real flows and virtual flows - and solving said problem wherein throughput demands are taken into account, and those network nodes (5) which are occupied with routing a virtual flow are powered down.