Virtual Switch Wild Card Flow Entries for Routing Table Reduction

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Solution Overview

Problem

Virtual switches experience performance slowdowns due to the increasing number of unique network traffic flows, as they rely on exact match routing tables that become larger and slower to search, lacking the resource augmentation available for physical switches.

Innovation Solution

Implementing wild card flow entries in routing tables that can cover multiple network traffic flows, reducing the size of the routing tables significantly and improving switching speed by allowing a single entry to manage many flows, with virtual switches receiving routing information from hypervisors to generate and manage these entries.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If exact match routing tables are used to manage network traffic flows, then routing precision is improved, but device complexity and search time increase as the number of flows grows

Engineering Contradiction:

Improverouting precisionVSAvoidrouting table size

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The routing table is segmented into two distinct components: exact match routing tables for precise flow identification and wild card routing tables for broader flow patterns. This segmentation allows the system to maintain high routing precision for specific flows while using compressed representations for groups of flows, thereby reducing overall routing table size and complexity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces a new dimension to routing table organization by adding wild card fields that enable multi-dimensional matching. Instead of relying solely on exact matches across all fields, the system can now match on some fields exactly while using wild cards for others, creating a more efficient routing table structure that reduces size without sacrificing routing accuracy.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Measurement precision

If exact match routing tables are used to ensure precise flow matching, then routing accuracy is improved, but switching speed deteriorates as routing table size increases

Engineering Contradiction:

Improverouting accuracyVSAvoidswitching speed

Core Design Contradiction:

Measurement precisionVSSpeed

Solution Approach 1:

The routing lookup process is segmented into two stages: first checking the compact wild card routing table for matching patterns, then verifying against the exact match routing table if needed. This segmentation reduces the average search time by filtering out many flows at the wild card level, thereby maintaining routing accuracy while improving switching speed.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The wild card routing table performs preliminary matching before the exact match lookup. By pre-processing and organizing flows into wild card patterns, the system eliminates the need to search through the entire exact match routing table for every packet, thus maintaining routing accuracy while significantly improving switching speed.

Inventive Principle:

Principle #10Preliminary action

3Speed

If additional physical resources are added to address slow switching, then switching performance is improved, but device complexity and cost increase

Engineering Contradiction:

Improveswitching performanceVSAvoidphysical resources

Core Design Contradiction:

SpeedVSDevice complexity

Solution Approach 1:

The patent changes the structural parameters of the routing table by introducing wild card fields and hierarchical organization. This parameter change enables more efficient memory utilization and faster lookup algorithms without requiring additional physical switching resources, thereby improving switching performance while avoiding increased device complexity.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

Instead of duplicating full routing table entries for each flow variation, the system creates compressed wild card representations that represent multiple flows. This copying strategy reduces the number of physical resources needed while maintaining the ability to handle diverse network flows efficiently.

Inventive Principle:

Principle #26Copying

4Adaptability or versatility

If the number of unique network traffic flows increases, then network versatility is improved, but switching performance deteriorates due to larger routing tables

Engineering Contradiction:

Improvenetwork versatilityVSAvoidswitching performance

Core Design Contradiction:

Adaptability or versatilityVSSpeed

Solution Approach 1:

The wild card routing table entries are designed to be universal, where a single entry can match multiple different network flows that share common patterns. This multi-functionality allows the system to handle increased network versatility and diverse traffic types while maintaining efficient switching performance through reduced routing table size.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS9325630B2Wild card flows for switches and virtual switches based on hints from hypervisors

Publication Date: 2016.04.26 RED HAT INC

AI summary

A network switch receives routing information pertaining to a virtual machine from a hypervisor managing the virtual machine. The switch adds a wild card entry associated with the virtual machine to a first routing data structure, wherein the wild card entry specifies one or more exact match fields, one or more wild card fields and an action to perform for packets having properties that match the one or more exact match fields.