MPLS Multicast Backup LSP Establishment via Node Protection Data
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Solution Overview
Problem
Current solutions for establishing and disestablishing backup paths in MPLS networks for real-time multicast applications are inefficient, leading to packet loss or duplication due to rapid or slow switching times in case of primary path failures.
Innovation Solution
Implementing a point-to-point protection mechanism where an upstream node receives node protection backup route data from a downstream protected node, determines a backup LSP, and transmits traffic through merge point nodes using forwarding information, ceasing transmission upon a timer expiration or receipt of a Make Before Break (MBB) route completion status message, and deleting the backup LSP when no longer needed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the backup path is established rapidly upon failure detection, then data continuity is improved, but packet loss occurs due to premature switching
Solution Approach 1:
The patent pre-establishes backup LSPs before primary path failures occur. The upstream node receives node protection backup route data from the downstream protected node and determines backup LSPs in advance, so that when a failure occurs, the backup path is already ready for immediate use without causing packet loss due to establishment delay or premature switching.
2Reliability
If the backup path is disestablished slowly after failure recovery, then packet duplication is avoided, but receiver experiences packet loss due to delayed switching back
Solution Approach 1:
The patent implements a feedback mechanism using a label reserve timer that tracks the status of primary and backup paths. When the primary path recovers, the timer controls the disestablishment of the backup path, ensuring switching back occurs at the optimal moment to avoid both packet loss and duplication. The upstream node ceases transmitting traffic along the backup LSP when the timer expires or when a make before break route completion status message is received.
3Reliability
If backup paths are established for all possible failures, then reliability is improved, but network complexity and resource consumption increase
Solution Approach 1:
The patent segments the protection mechanism by establishing backup LSPs only for specific downstream protected nodes that require protection, rather than blanket protection for all nodes. The upstream node receives node protection backup route data from specific downstream nodes and establishes backup paths selectively, reducing overall network complexity while maintaining reliability for critical paths.
4Reliability
If backup paths are established for all possible failures, then reliability is improved, but network resources and bandwidth consumption increase
Solution Approach 1:
The patent segments the network into protected and non-protected segments, establishing backup LSPs only where needed based on service level requirements and failure criticality. This selective approach maintains reliability for important multicast applications while avoiding unnecessary resource consumption in less critical network segments.
Solution Approach 2:
The patent applies different protection qualities to different parts of the network based on local requirements. The upstream node determines backup LSPs according to node protection backup route data from specific downstream nodes, providing enhanced protection locally where needed while using standard paths elsewhere, thus optimizing resource usage.
Data Source
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AI summary
In one aspect, the disclosure includes an apparatus comprising a processor configured to receive node protection backup route data at an upstream node and determine at least one backup route to at least one merge point node of a protected link or node according to the node protection data. In another aspect, the disclosure includes an apparatus comprising a processor configured to: receive at an upstream component information from a downstream component, wherein the received information comprises one or more of the following data elements related to one or more merge point nodes of a protected node: a number of leaf nodes, a plurality of merge point node addresses, a plurality of merge point node label reserve times and a plurality of merge point node forwarding labels, and establish a backup tunnel at the upstream component using at least one of the data elements received from the downstream component.