Method, apparatus, and system for setting up bidirectional point-to-multipoint label switched path

A router, serving as a source node of a bidirectional point-to-multipoint label switched path, and comprising a sending unit and a receiving unit, wherein:

• the sending unit is configured to send a Path message to each leaf node, wherein the Path message carries an indication of setting up a bidirectional point-to-multipoint label switched path and a label distributed that is to the leaf node;
• and the receiving unit is configured to receive a Resource Reservation message from each leaf node, wherein the Resource Reservation message carries a label distributed to the source node;
• or
• the sending unit is configured to send a Path message to each leaf node, wherein the Path message carries an indication of setting up a bidirectional point-to-multipoint label switched path;
• and the receiving unit is configured to receive a Resource Reservation message from each leaf node, wherein the Resource Reservation message carries a label distributed to the source node, and a label distributed to the leaf node itself or a leaf node label request;
• and
• when the Resource Reservation message carries the leaf node label request, the sending unit is further configured to send a Path message that carries a leaf node label to the leaf node.

A router, serving as a leaf node of a bidirectional point-to-multipoint label switched path, and comprising:

• a receiving unit, configured to receive a Path message from a source node, wherein the Path message carries an indication of setting up a bidirectional point-to-multipoint label switched path and a label that is distributed to the leaf node;
• and a sending unit, configured to send a Resource Reservation message to the source node, wherein the Resource Reservation message carries a label distributed to the source node;
• or
• a receiving unit, configured to receive a Path message from a source node, wherein the Path message carries an indication of setting up a bidirectional point-to-multipoint label switched path;
• and a sending unit, configured to send a Resource Reservation message to the source node, wherein the Resource Reservation message carries a label distributed to the source node, and a label distributed to the leaf node itself or a leaf node label request;
• wherein
• when the Resource Reservation message carries the leaf node label request, the receiving unit is further configured to receive from the source node a Resource Reservation message that carries a leaf node label.

A system for setting up a bidirectional point-to-multipoint label switched path, comprising a source node router and multiple leaf node routers, wherein:

• the source node router is configured to:
• send a Path message to each leaf node router, and receive a Resource Reservation message from each leaf node router, wherein the Path message carries an indication of setting up a bidirectional point-to-multipoint label switched path and a label that is distributed to the leaf node, and the Resource Reservation message carries a label distributed to the source node;
• and
• the leaf node router is configured to:
• receive the Path message from the source node router, and send the Resource Reservation message to the source node, wherein the Path message carries the indication of setting up the bidirectional point-to-multipoint label switched path and the label that is distributed to the leaf node, and the Resource Reservation message carries the label distributed to the source node;
• or
• the source node router is configured to:
• send a Path message to each leaf node router, and receive a Resource Reservation message from each leaf node router, wherein the Path message carries an indication of setting up a bidirectional point-to-multipoint label switched path, and the Resource Reservation message carries a label distributed to the source node, and a label distributed to the leaf node itself or a leaf node label request;
• when the Resource Reservation message carries the leaf node label request, the source node router is further configured to send a Path message that carries a leaf node label to the leaf node router;
• and
• the leaf node router is configured to:
• receive the Path message from the source node router, and send the Resource Reservation message to the source node, wherein the Path message carries the indication of setting up the bidirectional point-to-multipoint label switched path, and the Resource Reservation message carries the label distributed to the source node, and the label distributed to the leaf node itself or the leaf node label request;
• when the Resource Reservation message carries the leaf node label request, the leaf node router is further configured to receive from the source node router a Resource Reservation message that carries the leaf node label.