Routing methods, systems, and computer program products

What is this patent about?

’562 is related to the field of network routing and packet forwarding, specifically within architectures that utilize segment routing to direct traffic through a network domain. Traditional routing often relies on complex state maintenance at every hop or global label distribution protocols that can struggle with scalability as networks grow. The background context involves the evolution of the Internet Protocol (IP) and the need for more efficient, path-based addressing mechanisms that can reduce latency and simplify the mapping between a node’s identity and the route taken to reach it.

The underlying idea behind ’562 is the dynamic derivation of segment identifiers through a mathematical combination of a stable, globally unique index and a locally significant base value. Rather than requiring every node to agree on a single global label for a destination, the invention allows each node to calculate a context-specific segment ID by adding a node-specific offset (the base value) to a universal index that represents the target nodal segment. This decoupling allows the network to maintain global reachability while respecting the local label space constraints of individual hardware components.

The claims of ’562 focus on a node configured to receive a globally unique index value and a local base value to compute both its own segment identifier and the identifier for the next hop in a path. The independent claims specifically cover the mechanism of calculating a next hop segment ID by applying the same global index to a second base value that has been reserved by the adjacent node. This ensures that as a packet traverses the network, the label used to identify the destination is automatically translated to match the expectations of the subsequent router in the sequence.

In practice, this system functions as a programmable forwarding plane where the path is encoded as a series of segments. When a packet arrives, the current node uses its internal segment routing global block (the base value) and the unique index to identify the traffic's destination within its own forwarding table. To move the packet forward, the node performs a label swap or imposition using a calculated value derived from the neighbor's base value, effectively performing a mathematical translation of the routing instruction that remains consistent across the entire domain.

This approach differs from prior solutions by eliminating the need for a centralized label distribution authority to synchronize every specific hop-by-hop label. By using a globally unique index as the constant variable in the routing equation, the invention allows for decentralized path computation. It cuts through the overhead of traditional MPLS or standard IP routing by enabling nodes to independently determine the correct forwarding labels for any destination, provided they know the base offsets used by their immediate neighbors.