Redundant Multicast Trees SRLG Conflict Mitigation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing multicast transport networks face inefficiencies in bandwidth usage and lack fault-resilience due to the NP-hard problem of finding disjoint paths for Shared Risk Link Groups (SRLGs), which complicates the provision of reliable protection mechanisms.
Innovation Solution
The implementation of Redundant Multicast Trees (RMTs) with node-disjoint paths and local detour paths to identify and mitigate actual SRLG conflicts, ensuring fault-resilient propagation of multicast traffic by determining detour paths only for confirmed SRLG conflicts, thereby reducing the number of required detour paths and bandwidth consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If point-to-multipoint (P2MP) trees are used for multicast, then bandwidth efficiency is improved, but fault-resilience deteriorates because finding two SRLG disjoint paths is NP-hard
Solution Approach 1:
The patent segments the multicast protection problem into two independent parts: (1) finding SRLG-disjoint primary and backup P2MP trees for fault protection, and (2) determining actual SRLG conflicts that require detour paths. This segmentation makes the NP-hard problem tractable by solving each part separately with appropriate algorithms, thereby maintaining bandwidth efficiency while achieving fault-resilience.
Solution Approach 2:
The patent performs preliminary identification of actual SRLG conflicts between the primary and backup P2MP trees before establishing detour paths. By pre-determining which potential SRLG conflicts are actual conflicts that require protection, the system avoids the complexity of handling all potential conflicts, thus achieving fault-resilience with reduced computational overhead and maintained bandwidth efficiency.
2Reliability
If detour paths are determined for all potential SRLG conflicts, then fault-resilience is improved, but bandwidth consumption increases
Solution Approach 1:
The patent applies local quality by determining detour paths only for actual SRLG conflicts rather than all potential conflicts. By identifying and protecting only the specific links that constitute actual SRLG conflicts, the system achieves fault-resilience with minimal bandwidth consumption, avoiding the waste of resources on hypothetical conflicts that do not require protection.
Solution Approach 2:
The patent uses partial action by selectively applying detour path determination only to actual SRLG conflicts rather than all potential conflicts. This partial approach achieves sufficient fault-resilience for the critical conflicts while avoiding excessive bandwidth consumption that would result from protecting all potential conflicts, thus optimizing the trade-off between reliability and resource usage.
Data Source
AI summary
A capability is provided for supporting fault-resilient multicast using multiple sources. A method for supporting fault-resilient propagation of multicast traffic using Redundant Multicast Trees (RMTs) includes identifying each potential Shared Risk Link Group (SRLG) conflict associated with a pair of RMTs providing node-disjoint paths to a plurality of destination nodes, identifying each potential SRLG conflict that is an actual SRLG conflict, and, for each actual SRLG conflict, determining a detour path for protecting the links of the actual SRLG conflict. The pair of RMTs includes a first RMT from a first multicast source node to each of the destination nodes and a second RMT from a second multicast source node to each of the destination nodes. Each potential SRLG conflict includes a plurality of links. A potential SRLG conflict is determined to be an actual SRLG conflict if first and second paths for one of the destination nodes over the respective first and second RMTs each traverse at least one link of the potential SRLG conflict.