Overlay Network Content Retrieval via Intermediary Node

The patent segments the notification process by introducing a third node (content location management node) that handles IP address change notifications separately from the content retrieval process. Instead of direct broadcasting to all nodes, the system divides the communication into: (1) mobile node notifies third node of IP change, (2) third node stores mapping information, (3) requesting node queries third node for content location. This segmentation reduces unnecessary message propagation while maintaining retrieval reliability.

The third information processing apparatus acts as an intermediary between the mobile node and other nodes in the overlay network. It receives IP address change notifications from the mobile node, stores the mapping between old and new IP addresses, and provides this information to nodes that need to retrieve content. This intermediary approach eliminates the need for direct broadcasting to all nodes, significantly reducing message traffic while ensuring content can still be retrieved.

The system performs preliminary action by having the mobile node notify the third node of its IP address change immediately upon occurrence, before other nodes need to retrieve content. The third node stores this mapping information in advance, so when content retrieval requests come in, the system already has the updated location information ready. This preliminary notification approach allows free mobility without causing message storms during content retrieval operations.

The third information processing apparatus serves as a mediator that decouples the mobility management from the content retrieval process. Mobile nodes can change IP addresses freely without directly impacting other nodes, as the third node handles the translation and routing information. This intermediary layer absorbs the frequency of IP changes and presents a stable interface to content requesting nodes, maintaining adaptability while controlling message traffic.

The patent segments the information update process by separating the content location management function from the content retrieval function. The third node (content location management node) maintains a separate database of IP address mappings, and only provides this information to nodes that actively request content. This segmentation ensures content location information remains accurate while avoiding unnecessary network overhead from broadcasting to all nodes.

Instead of notifying all nodes of IP address changes (excessive action), the system uses a partial approach where only the third node receives and stores the IP change information, and only provides it to nodes that need it for content retrieval. This partial action approach maintains sufficient information accuracy for content location while significantly reducing network overhead.