Abstract: Provided is a management-system for use in a network environment including a first and second IP networks and a transport network which connects the first and second IP networks. The management system includes: a converter for optimizing a path in an IP-domain via a first algorithm and for converting IP-traffic-signals into transport-traffic-signals; and an optimiser which optimizes a topology that overlays the transport network by optimizing channels in the transport-network according to at least one second algorithm. The first algorithm is an IP multi protocol label switching routing optimization algorithm. The second algorithm is an algorithm based on a plurality of constraints and objectives such as a flow conservation constraint, logical link capacity constraint, optical router port constraint, wavelength cost objective, optical router port occupation objective, advertised link number objective, spare capacity objective, wavelength re-use benefit objective and optical service level agreement constraint.

Abstract: Network-systems comprising IP-networks with nodes (label switched routers) and edge-nodes (those routers coupled to a transport-network) and a transport-network (optical network) comprising channel-switches (optical cross connects) and a management-system for managing networks in an overlay environment (where the topology of the transport.network is not known to the management-system) deal with traffic non-optimally. By providing said management-system with a converter for converting IP-traffic-signals into transport-traffic-signals thereby assuming that both IP-networks are coupled via a star-network with said transport-network corresponding to a star of said star-network, and with an optimiser for in response to said converting optimising a use of channels in said transport-network according to an algorithm, network-systems can handle traffic more optimally. Said algorithm is defined by at least several constraints and several objectives.