Apparatus and method for establishing tunnels between nodes in a communication network

An apparatus for establishing tunnels between nodes along a packet transfer route in a communication network including a plurality of relay nodes and a plurality of management servers, the plurality of relay nodes including a first relay node and a second relay node and one or more intermediate relay nodes positioned between the first relay node and the second relay node along the packet transfer route, the plurality of management servers including a first management server managing the first relay node and a second management server managing the second relay node, the apparatus serving as any one of the plurality of management servers other than the first management server, the apparatus comprising:

• a processor to receive a request message for resolving one or more relay-node addresses useable to transfer a packet to the second relay node, the request message including a destination address of the packet to be transferred;
• and
• a memory to:
• store a management server address in association with the destination address included in the received request message,
• store the one or more relay-node addresses to be added in the request message, the one or more relay-node addresses respectively identifying one or more relay nodes included in the plurality of relay nodes, and
• store information identifying whether the apparatus is the second management server managing the second relay node,
• wherein when the apparatus is other than the second management server, the apparatus, upon receiving the request message, adds the one or more relay-node addresses to the received request message, and transfers the request message to the management server address;
• when the apparatus is the second management server, the apparatus, upon receiving the request message, creates a reply message and transmits the created reply message,
• the memory holds determination information for determining whether the one or more relay-node addresses is to be added to the request message, and
• the apparatus adds a part, all, or none of the one or more relay-node addresses to the request message, based on the determination information.

An apparatus for establishing tunnels between nodes along a packet transfer route in a communication network including a plurality of relay nodes, the plurality of relay nodes including a first relay node and a second relay node and one or more intermediate relay nodes positioned between the first relay node and the second relay node along the packet transfer route, a packet being transferred from the first relay node to the second relay node via the one or more intermediate relay nodes, each of the tunnels communicably coupling a pair of relay nodes along the packet transfer route, the apparatus serving as any one of the one or more intermediate relay nodes, the apparatus comprising

• a processor to:
• receive, from a downstream relay node that is positioned adjacent to the apparatus on a downstream side along the packet transfer route, a reply message storing relay-node addresses identifying the downstream relay node and at least one intermediate relay node positioned between the downstream relay node and the first relay node along the packet transfer route, the reply message being transmitted in response to a request message that is transmitted from the first relay node to resolve a relay-node address of the second relay node;
• establish a tunnel between the apparatus and the downstream relay node in association with the relay-node address of the downstream relay node;
• update the reply message by removing the relay-node address of the downstream relay node from the reply message;
• and
• transfer the updated reply message to an upstream relay node that is adjacently positioned on an upstream side of the packet transfer route.