Multicasting method in network including T-MPLS network and WDM network and apparatus therefor

A method of operating a multicasting switch connected to a transport multiprotocol label switching (T-MPLS) network in a network including the T-MPLS network and a wavelength division multiplexing (WDM) network, the method comprising:

• requesting the establishment or release of a multicasting path by transmitting a multicasting request signal or a multicast release signal including a label switch path (LSP) ID and a label switch router (LSR) ID to an upper node;
• establishing a multicasting path to a lower node by storing the LSP ID and the LSR ID included in the multicasting request signal transmitted from the lower node, or releasing a multicasting path to the lower node by erasing the LSP ID and the LSR ID included in the multicast release signal transmitted from the lower node;
• and
• including the LSP ID of the lower node to a T-MPLS signal and multicasting the T-MPLS signal,
• wherein the requesting of the establishment or release of a multicastinq path comprises:
• when the LSP ID and the LSR ID are first stored by a lower node, establishing a multicasting path corresponding to the first stored LSP ID and the LSR ID and, at the same time, requesting an upper node to establish a multicastinq path.

A network switch connected to a wavelength division multiplexing (WDM) network of a network including a transport multiprotocol label switching (T-MPLS) network and the WDM network, the network switch comprising:

• an optical drop and continue (D&C) switch configured to drop an optical multicasting signal transmitted via the WDM network;
• and
• a multicasting switch configured to convert the optical multicasting signal, which has been dropped by the optical D&C switch, into a T-MPLS signal and multicast the converted T-MPLS signal,
• wherein the multicasting switch requests the establishment or release of a multicasting path by transmitting a multicasting request signal or a multicast release signal including a label switch path (LSP) ID and a label switch router (LSR) ID to an upper node, and
• establishes a multicasting path to a lower node by storing the LSP ID and the LSR ID included in the multicasting request signal transmitted from the lower node or releases a multicasting path to the lower node by erasing the LSP ID and the LSR ID included in the multicast release signal transmitted from the lower node,
• wherein when an LSP ID and an LSR ID are first stored by a lower node, the multicastinq switch establishes a multicastinq path corresponding to the first stored LSP ID and the LSR ID and, at the same time, requests the establishment of a multicastinq path from an upper node.

A switch hub connected to a wavelength division multiplexing (WDM) network of a network including a transport multiprotocol label switching (T-MPLS) network and the WDM network, the switch hub comprising:

• an optical hub switch configured to multicast an optical multicasting signal to the WDM network;
• and
• a multicasting switch configured to convert a T-MPLS signal transmitted from the T-MPLS network into the optical multicasting signal and transfer the converted optical multicasting signal to the optical hub switch,
• wherein the multicasting switch requests the establishment of a multicasting path by transmitting a multicasting request signal including a label switch path (LSP) ID and a label switch router (LSR) ID to an upper node, or requests the release of a multicasting path by transmitting a multicasting release signal including the LSP ID and the LSR ID to the upper node,
• establishes a multicasting path to a lower node by storing the LSP ID and the LSR ID included in the multicasting request signal transmitted from the lower node, or
• releases a multicasting path to the lower node by erasing the LSP ID and the LSR ID included in the multicast release signal transmitted from the lower node,
• wherein multicastinq switch establishes a multicastinq path corresponding to the first stored LSP ID and the LSR ID and, at the same time, requests the establishment of a multicastinq path from an upper node.