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 management systems comprise generators for generating control signals and manage a sum of all traffic signals per network-unit or per link in a network by supplying the control signals to controllers which take action. The efficiency of such management can be improved a lot, by distinguishing between traffic signals of a first kind and traffic signals of a second kind, calculating functions of at least traffic signals of one kind, and comparing calculated functions with thresholds and generating control signals in dependence of comparison results. The distinguishing can be done between controllable traffic signals and uncontrollable traffic signals and/or between traffic signals forming part of services having a guaranteed quality-of-service-level and traffic signals forming part of services not having said guaranteed quality-of-service-level.

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.