A three-way handshake method for optical messaging in a multi-domain optical network that includes a first pass from a source domain to a destination domain through intermediate domains on candidate working paths, collecting information identifying available routing resources for each working path, calculating a working path metric and storing each of the metrics at the respective border node, determining a path key of the topology of each domain working path and using the path key to identify the path outside its domain and determining the best working paths and border nodes to use. A second pass using the path keys for identifying the working path in each domain and reserving the identified routing resources and selecting which routing resources to use. A third pass identifying the selected routing resources and establishing an optical signaling message path between the source node and the destination node.