SPBM Network Path Switching for Link Failure Recovery
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Shortest Path Bridging (SPB) networks face challenges in efficiently managing link state information and forwarding packets due to the complexity of Spanning Tree Protocol (STP) and the need for stable, non-blocking layer-2 networks, particularly in large-scale environments.
Innovation Solution
The implementation of SPBM (Shortest Path Bridging-MAC) mode, which uses SPB-IS-IS protocol for link state synchronization and calculates forwarding paths, employs BEB and BCB devices for packet encapsulation and forwarding, and establishes multiple forwarding paths for service instances across B-VLANs, enabling dynamic path switching upon link failures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If Spanning Tree Protocol (STP) is used to manage link state information, then network stability is maintained, but link utilization ratio decreases and network blocking occurs
Solution Approach 1:
The patent segments the network into multiple virtual channel groups (VC groups), each with its own spanning tree instance. This allows different segments of the network to operate independently, enabling load balancing across multiple paths while maintaining stability within each segment. The segmentation of forwarding paths resolves the contradiction by allowing parallel operation of multiple trees instead of a single blocking tree.
Solution Approach 2:
The patent implements dynamic path selection by calculating multiple shortest path trees and dynamically selecting forwarding paths based on current network conditions. The system can switch between different VC groups and their associated spanning trees dynamically, transforming the static blocking nature of traditional STP into a dynamic load-balancing system that maintains stability while improving utilization.
2Productivity
If multiple forwarding paths are established for service instances, then load balancing and network utilization improve, but device complexity increases
Solution Approach 1:
The patent creates universal VC group structures that can be reused across multiple service instances. Each VC group represents a reusable forwarding path template that can be instantiated multiple times, reducing the overall complexity of managing multiple forwarding paths. This multi-functionality approach allows the same VC group structure to serve multiple purposes and service instances.
Solution Approach 2:
The patent performs preliminary calculation and establishment of multiple virtual channel groups and their associated spanning trees before actual packet forwarding begins. By pre-computing the forwarding paths and organizing them into structured VC groups, the system reduces the complexity of real-time path management while maintaining the benefits of multiple forwarding paths for load balancing.
3Productivity
If SPB-IS-IS protocol is used for link state synchronization, then parallel shortest path calculation is achieved, but protocol complexity and implementation difficulty increase
Solution Approach 1:
The patent implements a nested structure where Virtual Channel Groups are nested within service instances, and spanning trees are nested within VC groups. This hierarchical nesting organizes the complex SPB-IS-IS protocol operations into manageable layers, reducing implementation complexity while maintaining parallel shortest path calculation capabilities across the nested structures.
Data Source
AI summary
A service instance in a BEB device is allocated B-VLANs. Each of the B-VLANs may be mapped to a different ECT algorithm. For each B-VLAN of the service instance, BEB device calculates a forwarding path between the BEB device and a remote BEB device to obtain different forwarding paths for different B-VLANs of the service instance. The BEB device forwards a data flow in a first forwarding path of the service instance, and switches the data flow from the first forwarding path to a second forwarding path of the service instance if a link failure is detected in the first forwarding path.