BIER Network Specified Path Forwarding via Hierarchical Level Information

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Solution Overview

Problem

The Bit Indexed Explicit Replication (BIER) technology lacks the capability to forward a specific flow via a specified path, which is essential for providing resource-guaranteed services and differentiated transmission of flows in intermediate networks.

Innovation Solution

A method and device that transmit information of a specified path through a BIER network, using a tree list with a root node and level information to indicate node locations, allowing BIER packets to be forwarded according to computed or configured paths, including the use of bit strings and BFR-IDs to identify nodes and levels, and enabling egress nodes to clear information and establish tunnels for non-BIER nodes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If BIER technology is used to simplify intermediate network control, then control complexity is reduced, but the capability to forward specific flows via specified paths is lost

Engineering Contradiction:
Improvecontrol complexityVSAvoidflow forwarding capability
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The path information is segmented into level-based hierarchical structures, where the specified path is divided into multiple levels with each level containing a set of nodes. This segmentation allows the BIER network to process and forward flows through specified paths while maintaining the simplified control plane, as each level can be independently processed by intermediate nodes.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a new dimension to BIER forwarding by adding level information to the traditional bit-based forwarding. Instead of only using bit strings to identify egress nodes, the solution adds a hierarchical level dimension, creating a two-dimensional forwarding structure (level × node set) that enables specified path forwarding while preserving BIER's simplicity.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Adaptability or versatility

If traditional IP forwarding is used, then flow transmission is supported, but intermediate network status recording increases complexity

Engineering Contradiction:
Improveflow transmission capabilityVSAvoidintermediate status recording
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent extracts the path specification functionality from traditional IP forwarding and integrates it into BIER by adding level information to the BIER header. This extraction allows BIER to gain specified path forwarding capability without adopting the complex status recording mechanisms of traditional IP routing, maintaining BIER's lightweight intermediate node operation.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The level information structure serves multiple functions simultaneously: it enables specified path forwarding, provides hierarchical organization for efficient processing, and maintains compatibility with existing BIER bit-based forwarding. This multi-functionality allows a single mechanism to address flow transmission requirements without increasing intermediate node complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP3364613B1Method and device for transmitting traffic via specified path
Publication Date: 2020.06.10 ZTE CORP
  • EP3364613B1 patent drawingFigure 1~2
  • EP3364613B1 patent drawingFigure 3
  • EP3364613B1 patent drawingFigure 4~5

AI summary

A method and device for transmitting a flow via a specified path are provided. The method includes: transmitting, by an ingress node of a BIER network, information of the specified path through which the flow passes. Another method includes: obtaining, by a BIER network node, information of the specified path through which the flow passes; and transmitting, by the node of the BIER network, a BIER packet of the flow according to the information of the specified path.