Three-way handshake (3WHS) optical network signaling protocol
View Patent ↗A method for optical network signaling processing of a signal from a first node to an end node through intermediate nodes is presented. The method comprises determining, in a first pass from the first node to the end node, available wavelengths and wavelength conversion at each node, the end node optimizing wavelengths using the available wavelengths and wavelength conversions, at each node, dropping a cross-connect command, in a second pass from the end node to the first node, choosing wavelengths for connection based on the optimizing step, in a third pass from the first node to the end node, receiving at each node a signal message and releasing unused cross-connect commands, the end node identifying the chosen wavelengths and releasing the unused resources, and transmitting the signal on the chosen wavelengths. Restoration paths can also be determined. Optimizing can include selecting and marking one or more backup wavelengths.
1. A method comprising:
determining, in a first pass from a first node to an end node, available wavelengths and available wavelength conversion resources at each node of one or more intermediate nodes;
optimizing a selection of a preferred path and a backup path, by the end node in the first pass from the first node to the end node, in accordance with the available wavelengths and wavelength conversion resources, the backup path maximizing sharing;
dropping, in a second pass from the end node to the first node, a cross-connect command at each node of the one or more intermediate nodes;
marking a wavelength as failed in the second pass from the end node to the first node;
selecting, by the first node, in the second pass from the end node to the first node, wavelengths for connection based on the optimizing and based on the marked failed wavelength;
receiving, in a third pass from the first node to the end node, a signal message and releasing unused cross-connect commands at the first node and each of the one or more intermediate nodes;
identifying by the end node, in the third pass from the first node to the end node, the selected wavelengths and releasing unused resources; and
transmitting a signal on the selected wavelengths.
2. The method according to claim 1 , the optimizing comprising:
determining by the end node, in the first pass from the end node to the first node, a number of wavelengths and marking the determined wavelengths as preferred; and
selecting and marking by the end node, in the first pass from the first node to the end node, one or more backup wavelengths.
3. The method according to claim 2 , wherein the wavelengths selected are the determined wavelengths marked as preferred.
4. The method according to claim 1 , further comprising determining, in the first pass from the first node to the end node, restoration wavelengths.
5. The method according to claim 4 , wherein determining further comprises:
establishing at the first node the available wavelengths and available wavelength conversion resources and available restoration paths;
getting and forwarding, at each node of the one or more intermediate nodes, the available wavelengths and the available wavelength conversion resources; and
getting and forwarding, at each node of the one or more intermediate nodes, the available restoration paths.
6. The method according to claim 1 , wherein determining further comprises:
establishing at the first node the available wavelengths and available wavelength conversion resources; and
getting and forwarding, at each node of the one or more intermediate nodes, the available wavelengths and the available wavelength conversion resources.
7. The method according to claim 1 , wherein the end node initializes the second pass and the first node initializes the third pass.
8. A non-transitory computer readable storage medium having computer readable program for operating on a computer for optical network signaling processing of a signal from a first node to an end node through one or more intermediate nodes, the program comprising instructions that cause the computer to execute operations comprising:
determining, in a first pass from the first node to the end node, available wavelengths and available wavelength conversion resources at each node of the one or more intermediate nodes;
optimizing a selection of a preferred path and a backup path, by the end node in the first pass from the first node to the end node, in accordance with the available wavelengths and wavelength conversion resources, the backup path maximizing sharing;
dropping, in a second pass from the end node to the first node, a cross-connect command at each node of the one or more intermediate nodes;
marking a wavelength as failed in the second pass from the end node to the first node;
selecting, by the first node, in the second pass from the end node to the first node, wavelengths for connection based on the optimizing and based on the marked failed wavelength;
receiving, in a third pass from the first node to the end node, a signal message and releasing unused cross-connect commands at the first node and each of the one or more intermediate nodes;
identifying by the end node, in the third pass from the first node to the end node, the selected wavelengths and releasing unused resources; and
transmitting a signal on the selected wavelengths.
9. The non-transitory computer readable storage medium according to claim 8 , wherein optimizing comprising:
determining by the end node, in the first pass from the end node to the first node, a number of wavelengths and marking the determined wavelengths as preferred; and
selecting and marking by the end node, in the first pass from the first node to the end node, one or more backup wavelengths.
10. The non-transitory computer readable storage medium according to claim 9 , wherein the wavelengths selected are the determined wavelengths marked as preferred.
11. The non-transitory computer readable storage medium according to claim 8 , further comprising determining, in the first pass from the first node to the end node, restoration wavelengths.
12. The non-transitory computer readable storage medium according to claim 11 , wherein determining further comprises:
establishing at the first node the available wavelengths and available wavelength conversion resources and available restoration paths;
getting and forwarding, at each node of the one or more intermediate nodes, the available wavelengths and the available wavelength conversion resources; and
getting and forwarding, at each node of the one or more intermediate nodes, the available restoration paths.
13. The non-transitory computer readable storage medium according to claim 8 , wherein determining further comprises:
establishing at the first node the available wavelengths and available wavelength conversion resources; and
getting and forwarding, at each node of the one or more intermediate nodes, the available wavelengths and the available wavelength conversion resources.
14. The non-transitory computer readable storage medium according to claim 8 , wherein the end node initializes the second pass and the first node initializes the third pass.