Abstract
Recent information and communication technologies ICT have shown that network communications is one of the largest consumers of energy. However energy efficiency in the general area of IT and computer networks must deal with the tradeoffs between performance, energy savings and Quality of Service . This paper examins an approach for dynamically managing network topologies to minimize energy consumption while meeting QoS requirements by turning links and nodes "routers" OFF or putting them into deep sleep . Simulation requirements are conducted in response of a wide rane of traffic loads.