Multilayer Protection Switching via Layered Tables
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Solution Overview
Problem
Current multilayer protection methods in networks fail to achieve efficient protection switching across different layers, particularly in scenarios where services like Pseudo-Wire (PW) and Label Distribution Protocol (LDP) services require rapid and reliable protection switching, often exceeding the 50ms standard.
Innovation Solution
A multilayer protection method and device that sets a protection table at each layer to provide forwarding path information, allowing for level-to-level finding and integration of actual forwarding paths, enabling efficient protection switching by selecting between main and spare paths based on layer protect status.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If protection switching is implemented on outer-layer tunnel, then services of inner layers should be switched to effective tunnel, but no effective method is proposed for multilayer protection at present
Solution Approach 1:
The patent divides the protection switching process into separate operations for each layer. Each layer has its own protection switching mechanism that operates independently, with inner layer services being switched first, then outer layer tunnels being switched. This segmentation allows complex multilayer protection to be managed through simpler, layer-by-layer operations.
Solution Approach 2:
The patent implements preliminary action by pre-establishing protection tunnels at each layer before failures occur. The system maintains backup paths and pre-configures switching parameters so that when a failure is detected, protection switching can be executed immediately without requiring complex real-time calculations or configurations.
2Speed
If protection switching speed is increased to meet 50ms standard, then service continuity is improved, but existing multilayer protection methods cannot achieve this speed
Solution Approach 1:
The patent uses preliminary action by pre-establishing protection tunnels and pre-configuring switching parameters at each layer. When a failure occurs, the system only needs to execute pre-planned switching operations rather than calculating new paths in real-time, enabling switching speeds under 50ms while maintaining manageable complexity through the pre-established framework.
Solution Approach 2:
The patent employs copying by creating backup protection tunnels that are copies of the working tunnels. These backup tunnels have identical structure and parameters, allowing for rapid switching by simply switching traffic to the pre-copied backup paths rather than establishing entirely new paths, thus achieving high switching speeds.
3Reliability
If all services are switched to outer-layer path during protection, then service continuity is ensured, but switching coordination across multiple layers becomes complex
Solution Approach 1:
The patent segments the protection switching operation by layer, with each layer handling its own switching independently. The inner layer services are switched first, then the outer layer tunnels are switched separately. This segmentation simplifies coordination by eliminating the need for complex cross-layer synchronization and allows each layer to operate with its own simplified switching logic.
Data Source
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AI summary
The disclosure provides a multilayer protection method and a multilayer protection device. The method comprises: judging whether or not a current layer functions as protection when it is needed to forward a message; when the current layer functions as protection, selecting a protection path according to a protection table of the current layer, otherwise selecting a working path; when the current layer is not an outermost layer, entering a next layer according to the protection path or the working path, and returning to a judgement of whether or not the next layer functions as protection; when the current layer is the outermost layer, forwarding the message according to the protection path or the working path selected by each layer. The multilayer protection method and the multilayer protection device provided by the disclosure can provide protection switching for multilayer application scenes in a network.