Logical Switch Flow Table Segmentation for Capacity Expansion

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Solution Overview

Problem

In existing network architectures, the limited capacity of hardware in switches restricts the ability to expand network functions or performance without replacing the switch, leading to increased costs for capacity expansion.

Innovation Solution

A method where a logical switch is formed by allocating flow tables and sending mapping information and flow entries across multiple physical switches, allowing each physical switch to process data packets based on the allocated flow tables and mapping information, enabling the expansion of processing capabilities without replacing existing hardware.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the hardware capability of the Switch is increased to expand network capacity, then the processing capability and flow table quantity are improved, but the device cost increases due to replacement

Engineering Contradiction:
Improveprocessing capabilityVSAvoiddevice cost
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The patent segments the flow tables into multiple groups and distributes them across multiple physical switches. Each physical switch handles a subset of flow tables, allowing the logical switch to support more flow tables than any single physical switch could handle individually. This segmentation enables capacity expansion without replacing the entire switch hardware.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Multiple physical switches are made to serve a common logical switch function through the flow table distribution mechanism. Each physical switch can handle multiple flow tables allocated to it, and the system as a whole provides unified switch functionality with expanded capacity. This multi-functionality allows existing hardware to be utilized for capacity expansion.

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

2Adaptability or versatility

If more flow tables are supported by the Switch pipeline, then the network function capacity is expanded, but the hardware limitation prevents further expansion without replacement

Engineering Contradiction:
Improveflow table quantityVSAvoidhardware capability
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

Flow tables are segmented into multiple groups and distributed across different physical switches. The controller manages the segmentation and allocation, assigning specific flow table groups to specific physical switches. This allows the system to support a total number of flow tables that exceeds the capacity of any single physical switch while maintaining manageable complexity through centralized control.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The controller acts as an intermediary that manages the distribution and coordination of flow tables across multiple physical switches. It handles the complexity of flow table allocation, mapping, and updates, shielding the physical switches from the complexity of managing a large total number of flow tables. This intermediary approach enables expanded flow table support without proportionally increasing device complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If existing Switch hardware is used without replacement, then the network stability is maintained, but the capacity expansion capability is limited

Engineering Contradiction:
Improvenetwork stabilityVSAvoidcapacity expansion capability
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

By segmenting flow tables across multiple existing physical switches, the system maintains the stability of existing hardware while collectively providing expanded capacity. Each physical switch continues to operate stably with its allocated flow tables, while the aggregate system achieves capacity expansion that would be impossible for any single switch.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Multiple physical switches are merged into a single logical switch entity through the flow table distribution mechanism. This merging allows the system to combine the capacities of multiple switches to achieve overall capacity expansion while each individual switch maintains its operational stability. The logical switch provides unified functionality with expanded capabilities.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3197106B1Switch processing method, controller, switch, and switch processing system
Publication Date: 2020.01.01 HUAWEI TECH CO LTD
  • EP3197106B1 patent drawingFigure 1~2
  • EP3197106B1 patent drawingFigure 3~4
  • EP3197106B1 patent drawingFigure 5

AI summary

Embodiments of the present invention provide a switch processing method, a controller, a switch, and a switch processing system. The method provided by the embodiments of the present invention is executed by the controller and a logical Switch, where the logical Switch includes at least two physical Switches. The method includes: allocating, by the controller, a flow table of the logical Switch to each physical Switch; sending, by the controller, mapping information, so that each physical Switch obtains the mapping information; and sending, by the controller, flow entries, so that each physical Switch obtains flow entries corresponding to each physical switch and processes a data packet. For the logical Switch for executing the method provided by the embodiments of the present invention, new physical Switches may be stacked on a basis of a physical structure of the logical Switch. This helps to maintain stability of an existing network topology, improves a processing capability of the logical Switch, and reduces impact on network running and costs of capacity expansion.