Routing Entry Aggregation for Larger-Capacity FIB Tables

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Solution Overview

Problem

The existing network devices face a challenge in storing a large number of routing entries due to limited storage capacity in hardware chips, which prevents meeting market requirements for larger FIB tables.

Innovation Solution

A method and apparatus that combine multiple routing entries into fewer entries by using a dimension-reduced combination algorithm, reducing storage space requirements and allowing additional entries to be stored.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the FIB table stores more routing entries to meet market requirements for large capacity, then the routing capacity is improved, but the storage space required exceeds the maximum capacity of the hardware chip

Engineering Contradiction:
Improverouting capacityVSAvoidstorage space
Core Design Contradiction:
Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The patent combines multiple routing entries into aggregated routing entries by merging routes with common characteristics (such as common destination address prefixes or common outbound interfaces). This reduces the total number of routing entries that need to be stored in the FIB table, allowing the hardware chip to store more routing information without exceeding its storage capacity limit.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The aggregated routing entry serves multiple original routing entries simultaneously, making it a multi-functional structure. A single aggregated routing entry can represent multiple specific routes, allowing one storage location to serve multiple routing functions, thereby reducing the overall storage space required while maintaining the ability to handle diverse routing scenarios.

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

2Loss of information

If the entire FIB table is delivered to each interface board, then the routing information is complete, but the storage capacity of the interface board is insufficient when the FIB table is large

Engineering Contradiction:
Improverouting information completenessVSAvoidstorage capacity
Core Design Contradiction:
Loss of informationVSQuantity of substance

Solution Approach 1:

The patent extracts and removes redundant routing information from the FIB table by aggregating similar routing entries. The extracted and merged routing information is then delivered to interface boards, reducing the amount of data transmitted and stored while maintaining the essential routing information needed for packet forwarding decisions.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The FIB table is segmented into aggregated routing entries that can be selectively delivered to interface boards. This segmentation allows the main control board to deliver only the necessary routing information to each interface board, reducing the storage burden on interface boards while ensuring they receive sufficient routing information for proper packet forwarding.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3737050B1Routing table entry generation method and apparatus, and trie tree generation method and apparatus
Publication Date: 2025.09.17 HUAWEI TECH CO LTD
  • EP3737050B1 patent drawingFigure 1
  • EP3737050B1 patent drawingFigure 2a
  • EP3737050B1 patent drawingFigure 2b

AI summary

Embodiments of this application disclose a routing entry generation method and apparatus and a tree generation method and apparatus. The routing entry generation method includes: obtaining M first routing entries, where each first routing entry includes a correspondence between a route and an outbound interface, and M≥2; and combining the M first routing entries to generate N second routing entries, where at least one of the N second routing entries includes a correspondence between a common route and an outbound interface, the common route is used to indicate two or more routes, N<M, and both N and M are integers. According to the method, the M first routing entries are combined into the N second routing entries, so that a quantity of first routing entries is significantly reduced, storage space of routing entries is saved, and the saved storage space can store additional routing entries, thereby meeting a market requirement for a large capacity.