Routing methods, systems, and computer program products

What is this patent about?

’938 is related to the field of network communications and, more specifically, to systems and methods for routing data using path-based protocol addresses. Traditional networking often relies on global address spaces where a destination address indicates where a node is, but not necessarily how to get there. This invention addresses the limitations of conventional routing by utilizing segment identifiers that define specific path portions, allowing for more granular control over how data traverses a network domain, particularly when bridging different protocol environments.

The underlying idea behind ’938 is the use of a path-based addressing scheme where a packet header contains explicit instructions for reaching intermediate nodes rather than just the final destination. By embedding segment identifiers that are specific to a particular network domain—such as an MPLS domain—the system can direct traffic to an intermediate path node that is not the ultimate destination. This allows the network to navigate complex topologies where a node might be reachable via multiple different path portions, including multi-hop routes, even when the final destination exists outside that specific protocol domain.

The claims of ’938 focus on an apparatus and method for processing packets at a current node by identifying a header that contains a plurality of segment identifiers. The independent claims specifically cover the mechanism of detecting a segment identifier for an intermediate path node, determining that data should be sent to that node, and selecting one of several available path portions to execute the delivery. Furthermore, the claims describe a mapping process where a node can replace or update these identifiers in the header to facilitate subsequent hops, effectively managing the packet's journey through region-scoped identifier spaces.

In practice, the invention functions by allowing a node to act as an intelligent relay that interprets region-specific labels to make forwarding decisions. When a packet arrives, the node looks at the segment identifiers to see if the next target is a path node within its own protocol region. If the destination node is outside an MPLS domain, the current node uses the segment identifier to bridge the gap, selecting between a direct path or a multi-hop path portion. This implementation enables the network to handle nested protocol addresses and scope-specific identifiers that only have meaning within a particular zone or region of the network.

This approach differentiates itself from prior art by moving away from the rigid distinction between names, addresses, and routes. Instead of relying on global routing tables that must be updated across the entire internet, ’938 utilizes path-based protocol addresses that inherently contain the route information. By using identifiers that are specific to the local topology or region, the system reduces the overhead of global address management and allows for more flexible traffic engineering. The ability to map and replace identifiers at each hop ensures that packets can transition seamlessly between different administrative or protocol domains without losing their routing context.