 A distinguishing feature of any NREN is its flexibility to meet the diverse needs of all its users.The numbers involved, coupled with increasing sophistication of personal applications, mean that managing demand and maintaining performance require the use of a hybrid Ethernet and Internet Protocol (IP) network architecture.The research community, driven by the development of various e-science grids, has developed large-scale applications that will individually use high amounts of bandwidth and can in some cases also have strict demands on the network that may require defined resources allocated temporarily to meet performance demands.