Packet forwarding device and control circuit thereof

A packet forwarding device that performs switching between a Work path and a Protection path of an MPLS network, the packet forwarding device comprising:

• a storage that stores therein
• a path selection table in which adjacent node numbers of the Work path and Protection path, a flag that indicates whether a link between the nodes is made up of a plurality of physical lines, a link aggregation number that identifies an aggregation of the plurality of physical lines, and destination information are set in association with one another for each flow number of a transfer packet,
• a node status table in which the node number and a status that indicates whether the node is active or inactive are set in association with each other, and
• a link aggregation status table in which the link aggregation number and a value that indicates whether all of the plurality of physical lines corresponding to the link aggregation number are active are set in association with each other;
• a path selection processor that acquires, when the flag acquired from the path selection table in accordance with a flow number of a packet acquired from an incoming path indicates that the link between the adjacent nodes is made up of a plurality of physical lines, link aggregation numbers of a Work path and a Protection path from the path selection table in accordance with the flow number to refer to the link aggregation status table, selects the Work path or the Protection path of which all the physical lines are active, and acquires destination information of the selected path from the path selection table;
• a transfer controller that transmits the received packet to an outgoing path decided by the destination information acquired by the path selection processor;
• and
• a monitor that monitors statuses of a link and a node on each outgoing path and updates the node status table and the link aggregation status table in accordance with whether the link and node are active or inactive.

A control circuit for controlling a packet forwarding device that performs switching between a Work path and a Protection path of an MPLS network, the control circuit comprising:

• a storage that stores therein
• a path selection table in which link numbers of the Work path and Protection path, a flag that indicates whether the link is made up of a plurality of physical lines, a link aggregation number for identifying an aggregation of the plurality of physical lines, and destination information are set in association with one another for each flow number of a transfer packet,
• a link status table in which the link number and an active or inactive state of the corresponding link are set in association with each other, and
• a link aggregation status table in which the link aggregation number and a value that indicates whether all of the plurality of physical lines corresponding to the link aggregation number are active are set in association with each other;
• a path selection processor that acquires, when the flag acquired from the path selection table in accordance with a flow number of a packet acquired from an incoming path indicates that the link is made up of a plurality of physical lines, link aggregation numbers of a Work path and a Protection path from the path selection table in accordance with the flow number to refer to the link aggregation status table, selects the Work path or the Protection path of which all the physical lines are active, and acquires destination information of the selected path from the path selection table;
• a transfer controller that transmits the received packet to an outgoing path decided by the destination information acquired by the path selection processor;
• and
• a monitor that monitors a status of a link on each outgoing path and updates the link status table and the link aggregation status table in accordance with whether the link is active or inactive.