Scalable Protection for Hierarchical Multicast in MPLS Ring Networks
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current multicast protection schemes in MPLS networks are not scalable and cannot provide fast protection times, as they require separate detour LSPs for each multicast connection and are impractical for multicast distribution trees due to their point-to-multipoint nature.
Innovation Solution
The solution involves provisioning two P2MP LSPs for each multicast connection in a ring-based network, with one LSP traveling clockwise and the other counter-clockwise, and using point-to-point protection tunnels to aggregate multicast traffic, reducing the number of required bypass tunnels and enabling fast, scalable protection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate detour LSPs are established for each multicast connection, then protection reliability is improved, but device complexity and resource consumption increase significantly
Solution Approach 1:
The patent merges multiple multicast connections into a single shared protection tunnel instead of establishing separate detour LSPs for each connection. The method provisions a primary P2MP LSP and a shared secondary P2MP LSP that can protect multiple multicast connections simultaneously, significantly reducing the number of required bypass tunnels and device complexity while maintaining protection reliability.
Solution Approach 2:
The shared secondary P2MP LSP serves as a universal protection resource that can protect multiple different multicast connections. This multi-functional protection tunnel can be dynamically activated for any failed primary LSP within the protected group, eliminating the need for dedicated protection paths for each connection and reducing overall system complexity.
2Reliability
If separate detour LSPs are established for each multicast connection, then protection coverage is improved, but scalability deteriorates
Solution Approach 1:
Multiple multicast connections are combined under a single shared protection tunnel, allowing the system to scale efficiently. As new multicast connections are added, they can utilize the existing shared protection infrastructure rather than requiring new dedicated protection paths, enabling the network to accommodate growing demands without proportional increases in complexity.
3Loss of time
If protection switching is implemented for multicast, then fast repair time is improved, but implementation complexity increases due to point-to-multipoint nature
Solution Approach 1:
The patent combines multiple P2MP LSPs into a shared protection tunnel structure that simplifies the switching mechanism. Instead of implementing complex individual switching logic for each multicast connection, the system uses a unified protection tunnel that can be activated for any failed primary LSP, reducing implementation complexity while achieving fast protection times under 50 milliseconds.
Data Source
AI summary
A novel fast and scalable protection mechanism for protecting hierarchical multicast service in ring based networks. The mechanism of the present invention is especially suitable for use in Multi-Protocol Label Switching (MPLS) ring based networks such as Metro Ethernet Networks (MENs). The mechanism provides fast protection for MPLS based point-to-multipoint (P2MP) Label Switched Paths (LSPs) in a scalable manner. Each multicast connection on each ring in the network is split into two sub-LSPs: a primary P2MP sub-LSP originating on a primary node and a secondary P2MP sub-LSP originating on a secondary node traveling opposite to the primary path. For each node to be protected, a point-to-point protection tunnel is provisioned from that node to a secondary node that forwards the packets to the secondary path on all child rings connected to that parent ring through the protected node and that are provisioned to receive the specific multicast connection. In the event of a failure, all the multicast traffic on that ring is directed through the protection tunnel to the secondary node. Upon exiting the protection tunnel, the packets are forwarded to the secondary LSP on the child rings for which this node is the secondary node and also continue along the primary LSP on the parent ring and along all child rings for which this node is the primary node.