An optical network comprising: sections for establishing optical paths; a plurality of optical edge routers for connecting IP networks to the optical network; and a plurality of optical cross connects, for connecting the optical edge routers by the optical paths, having switching sections (1422, 1423) with respect to an optical pulse, wherein each of the optical edge routers has both of: an optical network control instance (INSp) for maintaining topology information in the optical network and switching / signalling the optical paths; and an IP network instance (INSi) for having a routing table in each of the IP networks and activating routing protocols between the IP networks and the IP network instance, characterized in that they comprise means adapted to: activate the routing protocols for exchanging route information among the IP networks among optical network control instances in the optical edge routers to which the IP networks are connected, exchange the route information of the IP networks between the IP network instance and the optical network control instance, and each of the optical edge routers further comprises a packet forwarding table generating unit which is adapted to generate a packet forwarding table which sets where a received packet is to be transmitted based on the routing table stored in the IP network instance and the topology information maintained in the optical network control instance. sections for establishing optical paths; a plurality of optical edge routers for connecting IP networks to the optical network; and a plurality of optical cross connects, for connecting the optical edge routers by the optical paths, having switching sections (1422, 1423) with respect to an optical pulse, wherein each of the optical edge routers has both of: an optical network control instance (INSp) for maintaining topology information in the optical network and switching / signalling the optical paths; and an IP network instance (INSi) for having a routing table in each of the IP networks and activating routing protocols between the IP networks and the IP network instance, an optical network control instance (INSp) for maintaining topology information in the optical network and switching / signalling the optical paths; and an IP network instance (INSi) for having a routing table in each of the IP networks and activating routing protocols between the IP networks and the IP network instance, characterized in that they comprise means adapted to: activate the routing protocols for exchanging route information among the IP networks among optical network control instances in the optical edge routers to which the IP networks are connected, exchange the route information of the IP networks between the IP network instance and the optical network control instance, and each of the optical edge routers further comprises a packet forwarding table generating unit which is adapted to generate a packet forwarding table which sets where a received packet is to be transmitted based on the routing table stored in the IP network instance and the topology information maintained in the optical network control instance. activate the routing protocols for exchanging route information among the IP networks among optical network control instances in the optical edge routers to which the IP networks are connected, exchange the route information of the IP networks between the IP network instance and the optical network control instance, and each of the optical edge routers further comprises a packet forwarding table generating unit which is adapted to generate a packet forwarding table which sets where a received packet is to be transmitted based on the routing table stored in the IP network instance and the topology information maintained in the optical network control instance.