MPLS Node Protection via Label Stack Segmentation
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Solution Overview
Problem
In MPLS networks where LSPs share labels, traditional node protection methods fail to determine the correct backup path for packets when a next hop fails, leading to potential network disruptions.
Innovation Solution
Implementing a method that identifies a label stack within packets, pops the corresponding next hop label, determines failure, and uses context tables to identify a backup path that merges with the LSP at a next-to-next hop, enabling the packet to bypass the failed hop and reach the destination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If LSPs share labels to reduce the number of labels maintained in the data plane, then resource consumption and processing demands are reduced, but the ability to provide node protection is lost because the network node cannot determine which backup path to use for a given LSP when a failure occurs
Solution Approach 1:
The patent segments the single shared label into multiple stacked labels, where each label in the stack corresponds to a different LSP. This allows the network node to identify which specific LSP a packet belongs to by examining the label stack, thereby restoring node protection capability while still sharing labels across multiple LSPs. The label stack structure enables individual failure detection and backup path selection for each LSP without requiring separate single labels for each LSP.
Solution Approach 2:
The patent implements nesting by placing multiple labels within a label stack structure, where labels are nested one inside another. The outer label provides LSP identification while inner labels provide additional routing information. This nested structure allows the system to maintain multiple LSP identities within a single data plane entry, enabling both label sharing and individual node protection for each nested LSP.
2Reliability
If traditional node protection methods are used with separate labels for each LSP, then backup path determination is possible, but the number of data plane states must remain directly proportional to the number of LSPs, increasing resource consumption
Solution Approach 1:
The patent merges multiple LSP identifiers into a single label stack structure that is processed together in the data plane. Instead of maintaining separate forwarding entries for each LSP, the system combines multiple labels into one stack that is pushed onto packets traversing any of the shared LSPs. This merging reduces the number of data plane states from being proportional to the number of LSPs to being proportional to the number of next hops, while preserving node protection capability.
Solution Approach 2:
The label stack structure serves multiple functions simultaneously: it identifies the specific LSP a packet belongs to, provides routing information for the current hop, and enables node protection by allowing the network node to determine backup paths for each individual LSP. This multi-functionality eliminates the need for separate labeling schemes for each function, reducing overall resource consumption while maintaining full node protection capability.
3Adaptability or versatility
If a network node maintains 100,000 labels for 100,000 LSPs in traditional MPLS, then each LSP can be individually managed, but the network node requires frequent updates and high processing demands
Solution Approach 1:
The patent introduces dynamics by implementing a label stack that can be flexibly modified at different network nodes along the LSP path. Labels are dynamically pushed and popped as packets traverse different hops, allowing the same underlying label structure to serve multiple LSPs with different routing requirements. This dynamic label manipulation reduces the need for frequent global label updates while maintaining individual LSP management flexibility.
Data Source
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AI summary
The disclosed computer-implemented method may include (1) receiving, at a network node within a network, a packet from another network node within the network, (2) identifying, within the packet, a label stack that includes a plurality of labels that collectively represent at least a portion of a label-switched path within the network, (3) popping, from the label stack, a label that corresponds to a next hop of the network node, (4) determining, based at least in part on the label, that the next hop has experienced a failure that prevents the packet from reaching a destination via the next hop, (5) identifying a backup path that merges with the label-switched path at a next-to-next hop included in the label-switched path, and then (6) forwarding the packet to the next-to-next hop via the backup path. Various other methods, systems, and apparatuses are also disclosed.