OTN Service Protection Path Allocation via APS/PCC Segmentation
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Solution Overview
Problem
In optical transport networks (OTN), existing service protection technologies face challenges in distinguishing and managing multiple service protections due to limited APS/PCC overhead bytes, leading to nesting relations and contention issues, which hinder effective service protection.
Innovation Solution
A method that determines and selects available APS/PCC paths for service protection by initializing and dividing APS/PCC overhead bytes into multiple parts, allowing any service monitoring mode to use any protection path, thereby preventing nesting and ensuring multiple service protections can coexist without contention.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If APS/PCC overhead bytes are divided through multiframes according to prior art standards, then the APS/PCC is equally divided into 8 parts for different service protections, but nesting relations occur between several service protections making them indistinguishable
Solution Approach 1:
The patent segments the APS/PCC overhead bytes by introducing a multiframe structure with specific identification fields. Each service protection is assigned a unique combination of multiframe type indicator (MTI) and multiframe connection indicator (MCI) values, creating distinct segments for different protection types (SNC/N, SPRing, etc.) within the overall APS/PCC structure. This segmentation allows multiple service protections to coexist without nesting confusion.
2Reliability
If multiple service protections are configured simultaneously on an ODUk trail, then service protection coverage is improved, but contention of APS/PCC paths occurs making service protection indistinguishable
Solution Approach 1:
The patent implements a feedback mechanism where each node in the service protection trail checks the APS/PCC overhead bytes to determine which protection paths are currently in use. The system maintains state information about allocated APS/PCC paths and uses this feedback to prevent allocation conflicts. When a service protection is established, it receives feedback about the assigned APS/PCC path, and this information is used to distinguish it from other protections in the network.
3Ease of manufacture
If APS/PCC paths are assigned according to prior art standards, then service protection can be established, but path contention occurs reducing service protection effectiveness
Solution Approach 1:
The patent applies preliminary action by pre-defining the multiframe structure and APS/PCC path allocation rules before service protections are actually established. The system pre-allocates APS/PCC paths to different service protections based on their requirements, using predetermined MTI and MCI value combinations. This preliminary allocation prevents path contention from occurring in the first place, rather than resolving conflicts after they arise.
Data Source
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AI summary
A method and device for service protection are provided. The method includes the following steps. Paths corresponding to automatic protection switching (APS)/protection communication channel (PCC) overhead bytes that are available to all nodes in a service protection trail are determined. A path for service protection is selected from the determined paths corresponding to the APS/PCC. The selected path is used for implementing service protection. Therefore, it is ensured that several service protections using APS/PCC may coexist in an optical transport network (OTN) and different kinds of service protection can be easily distinguished.