IP + Optical Technology

working on “IP + optical ” network technology. Up to now, the optical network and IP (Internet protocol) network have been managed sepa-rately, but we are integrating them in the form of an IP + optical multilay-er network (MLN), as shown in Fig. 1. The idea here is to introduce a server-based traffic engineering (TE) approach into a multilayer network consisting of IP and optical layers. In other words, the IP optical TE server controls both the IP and optical lay-ers and optimizes all the network resources in both the IP and optical layers. This new network consists of client and server networks. The serv-er network provides the optical layer except for electrical IP packet for-warding at border nodes. A core node of the server network is an opti-cal transport node, which operates at ultrahigh speed by eliminating electrical processing of packets. Examples of core nodes include reconfigurable opti-cal add/drop multiplexers (ROADMs) and optical cross connects (OXCs). The border and core nodes are controlled by a common control plane called gen