Overlay Network Node Multipath Forwarding via Data Path Notification

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Solution Overview

Problem

In NVO3 networks, tenant systems can become unreachable due to virtual access point status changes, and multi-homed NVEs complicate unicast and multicast traffic forwarding, leading to issues with dynamic routing and address mapping updates, which existing technologies fail to address effectively.

Innovation Solution

A method and apparatus for handling packet traffic by receiving a data path notification message with forwarding policy information, determining the overlay network address destination maps to multiple underlay addresses, and selecting one address based on this information to forward packets, using an overlay network node with circuitry including a processor and memory to implement this process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If tenant systems are made multi-homed to improve reliability and avoid single points of failure, then system reliability improves, but forwarding complexity and routing decision difficulty increase

Engineering Contradiction:
Improvetenant system reachabilityVSAvoidforwarding complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent introduces a Data Path Notification (DPN) message as an intermediary mechanism between peer NVEs to convey forwarding policy information. This mediator resolves the complexity by providing structured guidance for packet forwarding decisions in multi-homed scenarios, eliminating the need for complex distributed routing protocols while maintaining reliability.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the parameter of forwarding information by introducing explicit forwarding policy data in DPN messages. Instead of relying on complex dynamic routing protocols, the system uses simplified forwarding rules conveyed through parameter changes in control messages, reducing forwarding complexity while maintaining multi-homed reliability.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If dynamic routing protocols are implemented to adapt to changing network conditions, then adaptability improves, but information synchronization between peer NVEs deteriorates due to lack of update propagation

Engineering Contradiction:
Improverouting adaptabilityVSAvoidrouting update propagation
Core Design Contradiction:
Adaptability or versatilityVSLoss of information

Solution Approach 1:

The patent implements feedback through Data Path Notification (DPN) messages that carry forwarding policy information from peer NVEs. When a tenant system's routing preferences change, the attached NVE sends DPN messages to peer NVEs, providing feedback that ensures all NVEs have synchronized forwarding information without requiring complex distributed routing protocol updates.

Inventive Principle:
Principle #23Feedback

3Stability of the object's composition

If centralized NVA control is used to manage address mappings, then forwarding consistency improves, but control plane overhead and update propagation time increase

Engineering Contradiction:
Improveforwarding consistencyVSAvoidupdate propagation time
Core Design Contradiction:
Stability of the object's compositionVSLoss of time

Solution Approach 1:

The patent segments the control plane by allowing peer NVEs to independently generate and exchange Data Path Notification (DPN) messages for local forwarding policy updates. This segmentation reduces reliance on centralized NVA for every forwarding update, thereby reducing update propagation time while maintaining forwarding consistency through distributed DPN message exchange.

Inventive Principle:
Principle #1Segmentation

4Measurement precision

If peer NVEs maintain detailed routing information for tenant systems, then forwarding precision improves, but memory requirements and information storage complexity increase

Engineering Contradiction:
Improveforwarding precisionVSAvoidmemory requirements
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent extracts only the essential forwarding policy information needed for packet forwarding into Data Path Notification (DPN) messages. Instead of maintaining detailed routing tables, peer NVEs store only the condensed forwarding rules conveyed through DPN messages, reducing memory requirements while maintaining sufficient forwarding precision through the extracted essential information.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP3308507B1Multipath forwarding in an overlay network
Publication Date: 2020.08.05 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3308507B1 patent drawingFigure 1
  • EP3308507B1 patent drawingFigure 2
  • EP3308507B1 patent drawingFigure 3

AI summary

The use of overlay networks, such as Network Virtualization using Overlays over Layer 3 (NVO3), is a growing trend to address networking issues in data centers that make use of virtualization and cloud computing techniques. Additional considerations may be required to support multipath forwarding scenarios.